B: Difference between revisions

From Embryology
mNo edit summary
mNo edit summary
 
(29 intermediate revisions by the same user not shown)
Line 12: Line 12:
:(More? [[Neural_Exam_-_Newborn_reflexes_-_plantar_reflex|Neural Exam - Newborn reflexes - plantar reflex]] | [[Neural System Development]] | [[Neonatal Development]] |  [http://www.nlm.nih.gov/medlineplus/ency/article/003294.htm Medline Plus - Babinski's reflex])
:(More? [[Neural_Exam_-_Newborn_reflexes_-_plantar_reflex|Neural Exam - Newborn reflexes - plantar reflex]] | [[Neural System Development]] | [[Neonatal Development]] |  [http://www.nlm.nih.gov/medlineplus/ency/article/003294.htm Medline Plus - Babinski's reflex])


===bacteria===  
==={{bacteria}}===  
:(bacterium, Greek, ''bakterion'' = little rod) A unicellular prokaryote cell, which exist in many different genetic and structural forms in many environments including [[C#commisural bacteria|commisural bacteria]] in the gastrointestinal tract and are also the cellular cause of infection.
:(bacterium, Greek, ''bakterion'' = little rod) A unicellular prokaryote cell, which exist in many different genetic and structural forms in many environments including [[C#commisural bacteria|commisural bacteria]] in the gastrointestinal tract and are also the cellular cause of infection.


:(More? [[Abnormal Development - Bacterial Infection]])
:(More? {{bacteria}})


===bacterial spore===
===bacterial spore===


:(bacterium, Greek, ''bakterion'' = little rod) An inactive and hardy form of [[B#bacteria|bacteria]], similar in function to a [[F#fungal spore|fungal spore]] that can survive in a metabolically dormant state for many years and can also withstand high temperatures, radiation, and toxic chemicals.
:(bacterium, Greek, ''bakterion'' = little rod) An inactive and hardy form of {{bacteria}}, similar in function to a [[F#fungal spore|fungal spore]] that can survive in a metabolically dormant state for many years and can also withstand high temperatures, radiation, and toxic chemicals.


:(More? [[Abnormal Development - Bacterial Infection]])
:(More? {{bacteria}})
[[File:Bacteria - gram-stained vaginal smear 01.jpg|thumb|alt=Bacteria - gram-stained vaginal smear|link=Abnormal_Development_-_Bacterial_Infection#Bacterial_Vaginosis|150px|alt=Bacterial vaginosis|Bacterial vaginosis (gram-stained vaginal smear)]]
[[File:Bacteria - gram-stained vaginal smear 01.jpg|thumb|alt=Bacteria - gram-stained vaginal smear|link=Abnormal_Development_-_Bacterial_Infection#Bacterial_Vaginosis|150px|alt=Bacterial vaginosis|Bacterial vaginosis (gram-stained vaginal smear)]]
===bacterial vaginosis===
===bacterial vaginosis===


:(BV, [[V#vaginitis|vaginitis]]) Clinical condition associated with loss of vaginal [[L#Lactobacillus|lactobacilli]] such as ''Lactobacillus acidophilus'', ''Lactobacillus crispatus'' and ''Lactobacillus jensenii'', and acquisition of complex communities of anaerobic bacteria such as species of ''Streptococcus''. A common condition, USA about 29% of reproductive age women. Can result in an increased risk for pre-term birth, HIV-1 acquisition and pelvic inflammatory disease.
:(BV, [[V#vaginitis|vaginitis]]) Clinical condition associated with loss of vaginal [[L#Lactobacillus|lactobacilli]] such as ''Lactobacillus acidophilus'', ''Lactobacillus crispatus'' and ''Lactobacillus jensenii'', and acquisition of complex communities of anaerobic {{bacteria}} such as species of ''Streptococcus''. A common condition, USA about 29% of reproductive age women. Can result in an increased risk for pre-term birth, HIV-1 acquisition and pelvic inflammatory disease.


:(More? [[Abnormal Development - Bacterial Infection]])
:(More? [[Abnormal Development - Bacterial Infection]])
Line 31: Line 31:
===bacteriophage===  
===bacteriophage===  


:(Greek, ''bakterion'' = little rod + ''phagein'' = to eat) or phage A [[V#virus|virus]] that infects [[B#bacteria|bacteria]].
:(Greek, ''bakterion'' = little rod + ''phagein'' = to eat) or phage A {{virus}} that infects {{bacteria}}.


:(More? [[Abnormal Development - Bacterial Infection]])
:(More? [[Abnormal Development - Bacterial Infection]])
[[File:Mouse oocyte balbini body EM01.jpg|thumb|150px|link=Oocyte Development|alt=Oocyte bambini body|Oocyte Balbiani body]]
[[File:Mouse oocyte balbini body EM01.jpg|thumb|150px|link=Oocyte_Development#Balbini_Body|alt=Oocyte bambini body|Oocyte Balbiani body]]
===Balbiani body===  
===Balbiani body===  
:([[M#mitochondrial cloud|mitochondrial cloud]]) collection of cell organelles ([[M#mitochondria|mitochondria]], [[E#endoplasmic reticulum|endoplasmic reticulum]], and granulofibrillar material) asymmetrically located beside the [[N#nucleus|nucleus]] in very young [[O#oocytes|oocytes]] in some species. Appears similar to germinal granule precursors seen some species that contain a definitive germ plasm ([[Fly Development|flies]], [[Worm Development|worms]], and [[Frog Development|frogs]]). Dynamic region involved in early cell polarity and RNA localisation in the oocyte. Named after Edouard-Gérard Balbiani (1823 – 1899) a French biologist who was among the first to describe them.
:([[M#mitochondrial cloud|mitochondrial cloud]]) collection of cell organelles ([[M#mitochondria|mitochondria]], [[E#endoplasmic reticulum|endoplasmic reticulum]], and granulofibrillar material) asymmetrically located beside the [[N#nucleus|nucleus]] in very young [[O#oocytes|oocytes]] in some species. Appears similar to germinal granule precursors seen some species that contain a definitive germ plasm ([[Fly Development|flies]], [[Worm Development|worms]], and [[Frog Development|frogs]]). Dynamic region involved in early cell polarity and RNA localisation in the oocyte. Named after Edouard-Gérard Balbiani (1823 – 1899) a French biologist who was among the first to describe them.
Line 52: Line 52:
===Barker Hypothesis===  
===Barker Hypothesis===  


:([[Abnormal Development - Developmental Origins of Health and Disease|Developmental Origins of Health and Disease]], DOHaD, Fetal Origins Hypothesis) Term named after the researcher, Barker who began a statistical analysis in the UK, of low birth weight data (early 1900's). The hypothesis has since been renamed as the Fetal Origins Hypothesis and proposes that in utero influences can lead too permanent changes in [[E#embryo|embryo]]/[[F#fetus|fetus]], low birth weight, which predisposes to chronic disease in adult life.  
:({{Developmental Origins of Health and Disease}}, {{DOHaD}}, Fetal Origins Hypothesis) Term named after the researcher, Barker who began a statistical analysis in the UK, of low birth weight data (early 1900's). The hypothesis has since been renamed as the Fetal Origins Hypothesis and proposes that in utero influences can lead too permanent changes in [[E#embryo|embryo]]/[[F#fetus|fetus]], low birth weight, which predisposes to chronic disease in adult life.  


:(More? [[Abnormal Development - Developmental Origins of Health and Disease|Developmental Origins of Health and Disease]])
:(More? {{Developmental Origins of Health and Disease}})


===Barlow test===
===Barlow test===
Line 62: Line 62:
:(More? [[Musculoskeletal System Development]] | [[Postnatal Development]] | Screening for developmental dysplasia of the hip: recommendation statement. PMID 16510673)
:(More? [[Musculoskeletal System Development]] | [[Postnatal Development]] | Screening for developmental dysplasia of the hip: recommendation statement. PMID 16510673)
[[File:Neutrophil EM01.jpg|thumb|150px|alt=Barr body|link=Molecular_Development_-_X_Inactivation|Barr body (human female neutrophil)]]
[[File:Neutrophil EM01.jpg|thumb|150px|alt=Barr body|link=Molecular_Development_-_X_Inactivation|Barr body (human female neutrophil)]]
===Barr body===  
==={{Barr body}}===  


:Name given to a visible cellular feature at the periphery of the nucleus, produced by the inactivation of a single X chromosome in females. Named after Murray Barr (1908 – 1995), a Canadian physician and medical researcher who first identified this cellular structure.
:Name given to a visible cellular feature at the periphery of the nucleus, produced by the inactivation of a single X chromosome in females. Named after Murray Barr (1908 – 1995), a Canadian physician and medical researcher who first identified this cellular structure.
Line 94: Line 94:
:(basal nuclei) A central nervous system (CNS) neural structure derived embryologically from the secondary vesicle telencephalon (endbrain) and the earlier primary vesicle prosencephalon (forebrain) from the neural tube. Structurally, it connects the cerebral cortex with the thalamus and brainstem and is associated with motor control and learning.
:(basal nuclei) A central nervous system (CNS) neural structure derived embryologically from the secondary vesicle telencephalon (endbrain) and the earlier primary vesicle prosencephalon (forebrain) from the neural tube. Structurally, it connects the cerebral cortex with the thalamus and brainstem and is associated with motor control and learning.


:(More? [[Neural - Basal Ganglia Development]] | [[Lecture - Ectoderm Development]] | [[Neural System Development]])
:(More? [[Neural - Basal Ganglia Development]] | {{ectoderm}} | [[Neural System Development]])
 
[[File:Human Stage22 spinal cord02.jpg|thumb|150px|alt=basal plate|link=Neural_-_Spinal_Cord_Development|basal plate]]
===basal plate===
===basal plate===
:The early [[N#neural tube|neural tube]] forms into two thicker lateral regions, the [[B#basal plate|basal plate]] and [[A#alar plate|alar plate]], which separate the [[F#floor plate|floor plate]] and  [[R#roof plate|roof  plate]] regions. The basal plate forms the ventral lateral region of the developing neural tube. At the level of  the spinal cord, this region will form the motor ventral horn region.
:The early {{neural tube}} forms into two thicker lateral regions, the [[B#basal plate|basal plate]] and [[A#alar plate|alar plate]], which separate the [[F#floor plate|floor plate]] and  [[R#roof plate|roof  plate]] regions. They are divided within the lateral wall of the tube by an indentation called the [[S#sulcus_limitans|sulcus limitans]]. The basal plate forms the ventral lateral region of the developing neural tube. At the level of  the spinal cord, this region will form the motor ventral horn region.


:(More? [[Neural System Development]] | Dev Biol [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?&rid=dbio.figgrp.2898 Development of the human spinal cord])
:(More? {{Spinal cord}} | {{Neural}} | Dev Biol [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?&rid=dbio.figgrp.2898 Development of the human spinal cord])


===base===  
===base===  
Line 105: Line 105:
:Another term for a [[N#nucleotide|nucleotide]] (usually a t c g) that forms deoxyribonucleic acid (DNA).  
:Another term for a [[N#nucleotide|nucleotide]] (usually a t c g) that forms deoxyribonucleic acid (DNA).  


:(More? [[Molecular Development - Genetics]])
:(More? {{Genetics}})


===base pair===  
===base pair===  
Line 111: Line 111:
:Double stranded DNA has nucleotides A-T, C-G, paired by hydrogen bonds (2 bonds for AT, 3 bonds for GC). Note this means that GC is harder to separate that AT.  
:Double stranded DNA has nucleotides A-T, C-G, paired by hydrogen bonds (2 bonds for AT, 3 bonds for GC). Note this means that GC is harder to separate that AT.  


:(More? [[Molecular Development - Genetics]])
:(More? {{Genetics}})


===basket cells===
===basket cells===
Line 117: Line 117:
:Central nervous system cerebellar interneurons located in the [[C#cerebellum|cerebellum]] molecular layer. These GABAergic neurons, and stellate cells, receive an excitatory synaptic input from granule cell axons (parallel fibers) and form an inhibitory synapse with Purkinje cells. The embryonic progenitors arise from the neuroepithelium at the level of of the fourth ventricle.
:Central nervous system cerebellar interneurons located in the [[C#cerebellum|cerebellum]] molecular layer. These GABAergic neurons, and stellate cells, receive an excitatory synaptic input from granule cell axons (parallel fibers) and form an inhibitory synapse with Purkinje cells. The embryonic progenitors arise from the neuroepithelium at the level of of the fourth ventricle.


:(More? [[Neural - Cerebellum Development]] | [[Lecture - Ectoderm Development]] | PMID 19500566)
:(More? {{Cerebellum}} | {{ectoderm}} | PMID 19500566)


===basonuclin 2===
===basonuclin 2===


:(bnc2, BNC2) A vertebrate zinc finger transcription factor that has a role in the proliferation of craniofacial mesenchymal cells and therefore in head and face development. (ortholog of drosophila disco proteins)
:(bnc2, BNC2) A vertebrate zinc finger transcription factor that has a role in the proliferation of craniofacial mesenchymal cells and therefore in {{head}} and face development. (ortholog of drosophila disco proteins)


:(More? PMID 16891417)
:(More? PMID 16891417)
Line 127: Line 127:
===battledore placenta===
===battledore placenta===


:(placenta battledore, ''batyldoure'' = a beating instrument) A term describing a placenta where the umbilical cord is attached at the margin. Occurs rarely and no described effects on placental function. The description probably comes from the similarity to a bat or paddle.
:(placenta battledore, ''batyldoure'' = a beating instrument) A term describing a placenta where the umbilical cord is attached at the margin. Occurs 7- 9% in singleton pregnancies and 24-33% in twin pregnancies and may effect placental function/fetal growth. The description probably comes from the similarity to a bat or paddle.


:(More? [[Placenta Development]])
:(More? {{Placenta abnormalities}} | [[Placenta Development]])


===Bayley Scales of Infant Development===  
===Bayley Scales of Infant Development===  
Line 136: Line 136:


:(More? [[Neural System Development]] | [[Neonatal_Development#Postnatal_Neural|Neonatal Development - Postnatal Neural]])
:(More? [[Neural System Development]] | [[Neonatal_Development#Postnatal_Neural|Neonatal Development - Postnatal Neural]])
===Becker muscular dystrophy===
:(BMD) A muscle degenerative disorder, similar to [[D#Duchenne_muscular_dystrophy|Duchenne muscular dystrophy]] (DMD), but allows muscles to function better than in DMD, slower progression, make a shortened form of the mutated protein. Named after Peter Emil Becker, a German doctor who first described this variant in the 1950s. PMID 13249581
:(More? [[Musculoskeletal_System_-_Muscle_Development#Becker_Muscular_Dystrophy|becker muscular dystrophy]] | PMID 13249581)
[[File:Tooth bell stage.jpg|thumb|150px|alt=tooth bell stage|link=Integumentary System - Tooth Development|bell stage]]
===bell stage===
:Tooth stage development occurring after cap stage  and before terminal differentiation. The cap folds in and acquires the form of a bell, secondary enamel knots appear.
{{Tooth stages}}
:(More?  [[Integumentary System - Tooth Development|Tooth Development]])


===beta-catenin===
===beta-catenin===
Line 147: Line 159:
:Endocrine cells located in the pancreas (pancreatic islets, islets of Langerhans) that secrete insulin and  increase glucose uptake. In development, their secretion stimulates fetal growth and the cells continue to proliferate to postnatal, in infancy most abundant. There are 4 different endocrine cell types ([[A#alpha cell|alpha]], [[B#beta cell|beta]], [[D#delta cell|delta]], [[F#F-cell|F-cells]]) in each pancreatic islet. Loss of these cells is associated with diabetes.
:Endocrine cells located in the pancreas (pancreatic islets, islets of Langerhans) that secrete insulin and  increase glucose uptake. In development, their secretion stimulates fetal growth and the cells continue to proliferate to postnatal, in infancy most abundant. There are 4 different endocrine cell types ([[A#alpha cell|alpha]], [[B#beta cell|beta]], [[D#delta cell|delta]], [[F#F-cell|F-cells]]) in each pancreatic islet. Loss of these cells is associated with diabetes.


:(More? [[Endocrine_-_Pancreas_Development|Pancreas Development]] | [[Abnormal Development - Maternal Diabetes|Maternal Diabetes]])
:(More? {{Pancreas}} | [[Abnormal Development - Maternal Diabetes|Maternal Diabetes]])


===beta-thalassemia===
===beta-thalassemia===
Line 153: Line 165:
:A group of hereditary blood disorders caused by anomalies in the synthesis of the beta chains of haemoglobin, resulting in variable phenotypes from severe anemia to clinically asymptomatic individuals. Total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union.  
:A group of hereditary blood disorders caused by anomalies in the synthesis of the beta chains of haemoglobin, resulting in variable phenotypes from severe anemia to clinically asymptomatic individuals. Total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union.  


:(More? [[Abnormal_Development_-_Genetic|Genetic Abnormalities]] | [[Cardiovascular System Development]] | PMID 20492708)
:(More? [[Abnormal_Development_-_Genetic|Genetic Abnormalities]] | {{Cardiovascular}} | PMID 20492708)
===bicornuate uterus===
===bicornuate uterus===


Line 159: Line 171:


:(More? [[Uterus Development]] | [[Lecture - Genital Development]] | [[Genital System - Abnormalities]])
:(More? [[Uterus Development]] | [[Lecture - Genital Development]] | [[Genital System - Abnormalities]])
 
[[File:Stage6 bf01.jpg|thumb|150px|alt=bilaminar embryo|link=Week 2|bilaminar embryo]]
===bilaminar embryo===
===bilaminar embryo===


:(two layer embryo) Term used in early embryonic development to describe the [[I#inner cell mass|inner cell mass]] differentiating to form an initial two layered structure ([[E#epiblast|epiblast]] and [[H#hypoblast|hypoblast]]). In human development, this occurs during [[Week 2|week 2]]. The epiblast layer will then form the majority of the embryo replacing the hypoblast during gastrulation during [[Week 3|week 3]].
:(two layer embryo) Term used in early embryonic development to describe the [[I#inner cell mass|inner cell mass]] differentiating to form an initial two layered structure ([[E#epiblast|epiblast]] and [[H#hypoblast|hypoblast]]). In human development, this occurs during [[Week 2|week 2]]. The epiblast layer will then form the majority of the embryo replacing the hypoblast during gastrulation during [[Week 3|week 3]].


===bile salts===
:(conjugated bile alcohols and bile acids) Liver synthesized compounds derived from cholesterol that function postnatally in the small intestine to solubilize and absorb lipids, vitamins, and proteins. These compounds act as water-soluble amphipathic detergents.
:(More? [[Gastrointestinal_Tract_-_Liver_Development|Liver Development]] | [[Gastrointestinal Tract Development]] | [[Lecture - Gastrointestinal Development]])
===biliary cells===  
===biliary cells===  


Line 187: Line 203:


:An [[E#enzyme|enzyme]] required to free biotin from its bound form for use. Biotinidase deficiency can be detected in newborn screening and treated with daily biotin supplementation.
:An [[E#enzyme|enzyme]] required to free biotin from its bound form for use. Biotinidase deficiency can be detected in newborn screening and treated with daily biotin supplementation.
:(More? {{Guthrie test}})
[[File:Autosomal recessive inheritance.jpg|thumb|150px|{{autosomal recessive}}]]
===biotinidase deficiency===
:Term used to classify a group of metabolic disorders which disrupt normal amino acid metabolism, particularly branched-chain amino acids, causing a buildup of acids which are usually not present. Multiple carboxylase deficiency (MCD) is an {{autosomal recessive}} metabolic disorder characterized primarily by cutaneous and neurologic abnormalities. Symptoms result from the inability to reutilize biotin, a necessary nutrient.
::{{ICD-11}} {{ICD11weblink}}1921636230 5C50.E Organic aciduria] - {{ICD11weblink}}1879509617 5C50.E0 Classical organic aciduria]
:(More? {{Guthrie test}})


===biparietal diameter===  
===biparietal diameter===  
Line 192: Line 217:
:An [[U#ultrasound|ultrasound]] measurement of Biparietal Diameter (BPD) is used to determine fetal age and normal development (small/large/abnormal) parameters. Measured as the diameter between the 2 sides of the head, used in clinical [[U#ultrasound|ultrasound]] measurements after 13 weeks (2.4 cm) to term (9.5 cm). It is one of the four typical [[U#ultrasound|ultrasound]] assessments of fetal size and age: Biparietal Diameter (BPD), [[H#head_circumference|Head Circumference]] (HC), [[A#abdominal_circumference|Abdominal Circumference]] (AC), and [[F#femur_length|Femur Length]] (FL).  
:An [[U#ultrasound|ultrasound]] measurement of Biparietal Diameter (BPD) is used to determine fetal age and normal development (small/large/abnormal) parameters. Measured as the diameter between the 2 sides of the head, used in clinical [[U#ultrasound|ultrasound]] measurements after 13 weeks (2.4 cm) to term (9.5 cm). It is one of the four typical [[U#ultrasound|ultrasound]] assessments of fetal size and age: Biparietal Diameter (BPD), [[H#head_circumference|Head Circumference]] (HC), [[A#abdominal_circumference|Abdominal Circumference]] (AC), and [[F#femur_length|Femur Length]] (FL).  


:(More? [[Ultrasound]] | [[Head Development]])
:(More? {{Ultrasound}} | {{Head}})
 
[[File:Birth- Magnetic Resonance Imaging 02.jpg|thumb|150px|alt=Birth MRI|link=Birth|Birth MRI]]
===birth===  
===birth===  


:(parturition) Term describing the physiological process of offspring (child) being born.  
:(parturition) Term describing the physiological process of offspring (child) being born.  


:(More? [[Birth]])
:(More? {{Birth}})


===birth rate===  
===birth rate===  
Line 204: Line 229:
:A statictical term typically calculated by dividing the number of live births in a population in a year by the mid-year resident population.  
:A statictical term typically calculated by dividing the number of live births in a population in a year by the mid-year resident population.  


:(More? [[Birth]] | [[Australia’s mothers and babies 2007]] | [http://embryology.med.unsw.edu.au/Stats/page1.htm Statistics])
:(More? {{Birth}} | [[Australia’s mothers and babies 2015]] | [http://embryology.med.unsw.edu.au/Stats/page1.htm Statistics])


===Bishop score===
===Bishop score===
:(Bishop's score) A clinical test prior to birth named after the obstetrician/gynaecologist Edward H. Bishop (1913-1995) who published a 1964 paper "Pelvic Scoring For Elective Induction". PMID 14199536
:(Bishop's score) A clinical test prior to birth named after the obstetrician/gynaecologist Edward H. Bishop (1913-1995) who published a 1964 paper "Pelvic Scoring For Elective Induction". PMID 14199536


:(More? [[Birth]] | PMID 14199536 | [http://agosonline.org/member-pages-in-memoriam/bishop-eh-1995.html 1995 In Memoriam])
:(More? {{Birth}} | PMID 14199536 | [http://agosonline.org/member-pages-in-memoriam/bishop-eh-1995.html 1995 In Memoriam])
[[File:Stage 22 image 214.jpg|thumb|150px|alt=Urinary Bladder (week 8)|link=Urinary_Bladder_Development|Urinary Bladder (week 8)]]
===bladder===  
===bladder===  


:([[U#urinary bladder|urinary bladder]]) The simplified term used to describe the [[U#urinary bladder|urinary bladder]] muscular sac for the storage of urine.
:([[U#urinary bladder|urinary bladder]]) The simplified term used to describe the [[U#urinary bladder|urinary bladder]] muscular sac for the storage of urine.


:(More?  [[Renal System Development]] | [[Lecture - Renal Development]])
:(More?  [[Urinary_Bladder_Development|Bladder Development]] | {{Renal}} | [[Lecture - Renal Development]])


===bladder exstrophy===  
===bladder exstrophy===  
Line 220: Line 246:
:(Greek, ''ekstriphein'' = "turn inside out") A congenital malformation with [[U#urinary bladder|urinary bladder]] open to ventral wall of abdomen (between umbilicus and pubic symphysis) and may have other anomolies associated with failure of closure of abdominal wall and [[U#urinary bladder|urinary bladder]] (epispadias, pubic bone anomolies).
:(Greek, ''ekstriphein'' = "turn inside out") A congenital malformation with [[U#urinary bladder|urinary bladder]] open to ventral wall of abdomen (between umbilicus and pubic symphysis) and may have other anomolies associated with failure of closure of abdominal wall and [[U#urinary bladder|urinary bladder]] (epispadias, pubic bone anomolies).


:(More? [[Renal System - Abnormalities]])
:(More? {{Renal abnormalities}})


===blastema===  
===blastema===  
Line 227: Line 253:


:(More? [[W#Wilms_tumour|Wilm's tumour]])
:(More? [[W#Wilms_tumour|Wilm's tumour]])
 
[[File:Human embryo day 5 label2.jpg|thumb|150px|alt=Blastocoel|link=Blastocyst Development|Blastocoel]]
===blastocoel===  
===blastocoel===  


:(blastocoele, blastocele) A fluid-filled cavity that forms in early development within the [[B#blastocyst|blastocyst]]. Initially the dividing cells form a solid cellular mass ([[M#morula|morula]]) continued cell division and compaction lead to the formation of this space or cavity. In humans, this cavity is present during the end of the first week and into the second week of development.  
:(blastocoele, blastocele) A fluid-filled cavity that forms in early development within the [[B#blastocyst|blastocyst]]. Initially the dividing cells form a solid cellular mass ([[M#morula|morula]]) continued cell division and compaction lead to the formation of this space or cavity. In humans, this cavity is present during the end of the first week and into the second week of development.  


:(More? [[Week 1]] | [[Week 2]] | [[Blastocyst]])
:(More? [[Week 1]] | [[Week 2]] | {{Blastocyst}})


===blastocyst===  
===blastocyst===  
Line 238: Line 264:
:(Greek, ''blastos'' = sprout + cystos = cavity) Term used to describe the hollow cellular mass that forms in early development. The blastocyst consists of cells forming an outer [[T#trophoblast|trophoblast]] layer, an inner cell mass and a fluid-filled cavity. The blastocyst inner cell mass is the source of true embryonic stem cells capable of forming all cell types within the [[E#embryo|embryo]]. In humans, this stage occurs in the first and second weeks after the [[Z#zygote|zygote]] forms a solid cellular mass ([[M#morula|morula]] stage) and before implantation.  
:(Greek, ''blastos'' = sprout + cystos = cavity) Term used to describe the hollow cellular mass that forms in early development. The blastocyst consists of cells forming an outer [[T#trophoblast|trophoblast]] layer, an inner cell mass and a fluid-filled cavity. The blastocyst inner cell mass is the source of true embryonic stem cells capable of forming all cell types within the [[E#embryo|embryo]]. In humans, this stage occurs in the first and second weeks after the [[Z#zygote|zygote]] forms a solid cellular mass ([[M#morula|morula]] stage) and before implantation.  


:(More? [[Blastocyst]] | [[Week 2]] | [[Stem Cells]])
:(More? {{Blastocyst}} | [[Week 2]] | [[Stem Cells]])


[[File:Human carnegie stage 3 label.jpg|thumb|150px|alt=blastocyst hatching|link=Blastocyst Development|Blastocyst Hatching (day 5)]]
===blastocyst biopsy===
:An  [[Assisted Reproductive Technology]]  preimplantation genetic diagnosis technique carried out at blastocyst stage (day 4-5), removes several trophoblast (trophoderm) cells, detects chromosomal abnormalities of both maternal and paternal origin and may detect cellular mosaicism.
:(More? [[Assisted Reproductive Technology]] | [[Preimplantation Genetic Diagnosis]] | {{Zygote}} | {{Morula}} | [[Week 1]] | [[Abnormal Development - Genetic|Genetic Abnormalities]])
===blastocyst hatching===
===blastocyst hatching===


:(Greek, ''blastos'' = sprout + cystos = cavity) Term used to describe the process of [[B#blastocyst|blastocyst]] emerging from the surrounding protective [[Z#zona pellucida|zona pellucida]]. The process may commence at the site of original spermatozoa fertilization and must occur before implantation can commence.
:(Greek, ''blastos'' = sprout + cystos = cavity) Term used to describe the process of [[B#blastocyst|blastocyst]] emerging from the surrounding protective [[Z#zona pellucida|zona pellucida]]. In human development this process occurs at the end of the first week (day 5-7) {{GA}} week 3. The location of hatching from the ZP can occur at the original spermatozoa entry site for fertilisation, and must complete before implantation can commence.
 
:(More? [[Blastocyst]] | [[Quicktime_Movie_-_Blastocyst_Contractions|Quicktime - Blastocyst Contractions]] | [[Movie_-_Blastocyst_Contractions|Flash - Blastocyst Contractions]] | [[Implantation]])


:(More? {{Blastocyst}} | [[Blastocyst Hatching Movie]] | {{Implantation}})
[[File:Human embryo day 2.jpg|thumb|150px|alt=Human Embryo (day 2) 4 blastomere|link=Morula|Human Embryo (day 2) 4 blastomeres]]
===blastomeres===
===blastomeres===


:Term used to describe the first cells formed by mitotic cell division of the [[Z#zygote|zygote]].
:Term used to describe the first cells formed by mitotic cell division of the [[Z#zygote|zygote]].


:(More? [[Zygote]] | [[Week 1]])
:(More? {{Zygote}} | {{Morula}} | [[Week 1]])
 
===blastomere biopsy===


:An  [[Assisted Reproductive Technology]] preimplantation genetic diagnosis technique carried out at cleavage stage (day 3), excluding poor quality embryos, detects chromosomal abnormalities of both maternal and paternal origin. May not detect cellular mosaicism in the embryo.
:(More? [[Assisted Reproductive Technology]] | [[Preimplantation Genetic Diagnosis]] | {{Zygote}} | {{Morula}} | [[Week 1]] | [[Abnormal Development - Genetic|Genetic Abnormalities]])
===blastopore===  
===blastopore===  


:The opening formed by the gastrulating cell migration in early [[B#blastula|blastula]] to [[G#gastrula|gastrula]] development.  
:The opening formed by the gastrulating cell migration in early [[B#blastula|blastula]] to [[G#gastrula|gastrula]] development.  


:(More? [[Week 2]] | [[Week 3]] | [[Frog Development]])
:(More? [[Week 2]] | [[Week 3]] | {{Frog}})


===blastula===  
===blastula===  
Line 263: Line 301:
::morula -> blastula ->  gastrula
::morula -> blastula ->  gastrula


:(More? [[Week 1]])
:(More? {{Blastocyst}} | [[Week 1]])


===blighted ovum===  
===blighted ovum===  
Line 277: Line 315:
===blood islands===  
===blood islands===  


:The initial small patches which form within [[M#mesoderm|mesoderm]] that differentiate into both the blood vessel wall and blood cells. These islands enlarge and connect together to form the initial vascular beds.  
:The initial small patches which form within {{mesoderm}} that differentiate into both the blood vessel wall and blood cells. These islands enlarge and connect together to form the initial vascular beds.  


:(More? [[Lecture - Early Vascular Development]] | [[Cardiovascular System - Blood Development]])
:(More? {{blood}} | [[Lecture - Early Vascular Development]])


===blood-brain barrier===
===blood-brain barrier===
Line 285: Line 323:
:(BBB) The barrier formed at the cellular level by endothelial cells of brain capillaries, differing in junctions, transport and glial association from those found in peripheral capillaries. Damage to this barrier can occur following injuries involving ischemia and reperfusion.
:(BBB) The barrier formed at the cellular level by endothelial cells of brain capillaries, differing in junctions, transport and glial association from those found in peripheral capillaries. Damage to this barrier can occur following injuries involving ischemia and reperfusion.


:(More? [[Neural System Development]] | [[Cardiovascular System Development]])
:(More? {{Neural}} | {{Cardiovascular}})


===blood-testis barrier===
===blood-testis barrier===
Line 291: Line 329:
:(BTB) In the testis this barrier is formed by tight junctions, basal ectoplasmic specializations, desmosome-like junctions and gap junctions between adjacent Sertoli cells near the basement membrane of the seminiferous epithelium. Historically referred to as a "barrier" as intravenous dyes in rodents failed to ‘stain’ the seminiferous tubules in the testis as well as in the brain, the blood-brain barrier (BBB).
:(BTB) In the testis this barrier is formed by tight junctions, basal ectoplasmic specializations, desmosome-like junctions and gap junctions between adjacent Sertoli cells near the basement membrane of the seminiferous epithelium. Historically referred to as a "barrier" as intravenous dyes in rodents failed to ‘stain’ the seminiferous tubules in the testis as well as in the brain, the blood-brain barrier (BBB).


:(More? [[Testis Development]] | [[Spermatozoa Development]] | [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2804914 PMC2804914])
:(More? {{Testis}} | {{Spermatozoa}} | [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2804914 PMC2804914])


===blueberry muffin baby===
===blueberry muffin baby===
Line 307: Line 345:
:A proto-oncogene protein located in the nucleus, which is a member of the Polycomb-group gene family (required to maintain the repression of homeotic genes). Expressed in range of stem cells including hematopoietic, neural and intestinal stem cells. Human BMI-1 gene on the short arm of chromosome 10 (10p13). [http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=18536716 PMID: 18536716]
:A proto-oncogene protein located in the nucleus, which is a member of the Polycomb-group gene family (required to maintain the repression of homeotic genes). Expressed in range of stem cells including hematopoietic, neural and intestinal stem cells. Human BMI-1 gene on the short arm of chromosome 10 (10p13). [http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=18536716 PMID: 18536716]


:(More? [[Gastrointestinal Tract Development]] | [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=164831 OMIM - proto-oncogene BMI-1])
:(More? {{Gastrointestinal}} | [https://omim.org/entry/164831 OMIM - proto-oncogene BMI-1])


===BOC===  
===BOC===  
Line 313: Line 351:
:Acronym for '''B'''rother '''o'''f '''C'''don a cell surface receptor. CDON is also a acronym for '''C'''ell adhesion molecule-regulated/'''d'''ownregulated by '''on'''cogenes. Both Boc and Cdon are cell surface receptors (for sonic hedgehog) of the immunoglobulin (Ig)/fibronectin type III that interact with each other, are coexpressed and involved in neural and muscle development.  
:Acronym for '''B'''rother '''o'''f '''C'''don a cell surface receptor. CDON is also a acronym for '''C'''ell adhesion molecule-regulated/'''d'''ownregulated by '''on'''cogenes. Both Boc and Cdon are cell surface receptors (for sonic hedgehog) of the immunoglobulin (Ig)/fibronectin type III that interact with each other, are coexpressed and involved in neural and muscle development.  


:(More? [[Developmental Signals - Sonic hedgehog]] | [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=608708 OMIM - BROTHER OF CDON])
:(More? [[Developmental Signals - Sonic hedgehog]] | [https://omim.org/entry/608708 OMIM - BROTHER OF CDON])


===Bochdalek hernia===
===Bochdalek hernia===
Line 334: Line 372:


:(More? [[Gastrointestinal Tract Development]] | [[Endocrine System Development]])
:(More? [[Gastrointestinal Tract Development]] | [[Endocrine System Development]])
 
[[File:Bone marrow histology 01.jpg|thumb|120px|alt=Bone marrow histology|link=Cardiovascular_System_-_Blood_Development|Bone marrow histology]]
===bone===  
===bone===  


Line 340: Line 378:


:(More? [[Bone_Development|Bone Development]] | [[Musculoskeletal System - Bone Development]] | [http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Bone/Bone.htm Blue Histology - Bone])
:(More? [[Bone_Development|Bone Development]] | [[Musculoskeletal System - Bone Development]] | [http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Bone/Bone.htm Blue Histology - Bone])
 
[[File:Hematopoietic and stromal cell differentiation.jpg|thumb|150px|alt=bone marrow stromal cells|link=Musculoskeletal_System_-_Bone_Development|bone marrow stromal cells]]
===bone marrow===  
===bone marrow===  


:The cellular components found within the core of bones, mainly long bones, which contain the adult blood stem cell population and a range of other cell types. Generally described as either red marrow (myeloid tissue) or yellow marrow (mainly fat cells.)  
:The cellular components found within the core of bones, mainly long bones, which contain the adult blood stem cell population and a range of other cell types. Generally described as either red marrow (myeloid tissue) or yellow marrow (mainly fat cells.)  


:(More? [[Musculoskeletal_System_-_Bone_Development|Musculoskeletal Development - Bone]] | [[Cardiovascular_System_-_Blood_Development|Blood Development]] | [[Musculoskeletal System Development]])  
:(More? {{Bone}} | {{Blood}} | {{Musculoskeletal}})  
 
===bone marrow stromal cells===  
===bone marrow stromal cells===  


:(BMSCs) These are pluripotental cells from bone marrow that can potentially differentiate into a range of connective tissue and muscle cell types (cardiomyocytes, rhabdomyocytes, hepatocytes, osteocytes, chondrocytes, tencoytes, adipocytes, smooth muscle cells). These cells have therefore been seen as a source of stem cells for tissue repair.  
:(BMSCs) These are pluripotental cells from bone marrow that can potentially differentiate into a range of connective tissue and muscle cell types (cardiomyocytes, rhabdomyocytes, hepatocytes, osteocytes, chondrocytes, tencoytes, adipocytes, smooth muscle cells). These cells have therefore been seen as a source of stem cells for tissue repair.  


:(More? [[Musculoskeletal_System_-_Bone_Development|Musculoskeletal Development - Bone]] | [[Cardiovascular_System_-_Blood_Development|Blood Development]] | [[Musculoskeletal System Development]])
:(More? {{Bone}} | {{Blood}} | {{Musculoskeletal}})
 
[[File:Borrelia-burgdorferi.jpg|thumb|150px|alt=borrelia burgdorferi|link=Abnormal Development - Bacterial Infection|borrelia burgdorferi]]
===borrelia burgdorferi===  
===borrelia burgdorferi===  


Line 358: Line 395:


:(More? [[Abnormal Development - Bacterial Infection]])
:(More? [[Abnormal Development - Bacterial Infection]])
[[File:Patent Ductus Arteriosus.jpg|thumb|150px|alt=Botallo's duct|}link=Cardiovascular_System_-_Patent_Ductus_Arteriosus|Botallo's duct]]
===Botallo's duct===


===Botallo's duct===
:([[D#ductus_arteriosus|ductus arteriosus]], ligamentum arteriosum, ductus Botallo, ductus Botalli)  A vascular shunt between pulmonary trunk and the aortic arch. This channel degenerates to form the ligamentum arteriosum (ligamentum Botalli). In preterm infants this channel may remain open as a patent [[D#ductus arteriosus|ductus arteriosus]]. Named after [[Embryology_Historic_Terminology#Botallo_duct|Leonardo Botallo]] an Italian surgeon in Paris (1530-1600).


:([[D#ductus_arteriosus|ductus arteriosus]]) A vascular shunt between pulmonary trunk and the aortic arch. This channel degenerates to form the ligamentum arteriosum (ligamentum Botalli). In preterm infants this channel may remain open as a patent [[D#ductus arteriosus|ductus arteriosus]]. Named after Leonardo Botallo an Italian surgeon in Paris (1530-1600).
:(More? [[Cardiovascular System - Patent Ductus Arteriosus|Patent Ductus Arteriosus]] | [[Cardiovascular System Development]] | [[Birth]])


:(More? [[Cardiovascular System Development]] | [[Birth]])
===bouquet stage===
:[[M#meiosis|Meiosis]] term used to describe in prophase the chromosome telomeres attachment to the inner nuclear envelope and form a cluster. This occurs before the onset of homologous pairing and synapsis. The name comes from the chromosomes resembling a "bouquet of flowers",  observed in all organisms except worms (caenorhabditis elegans) and flies (drosophila).


:(More? {{Meiosis}} | {{Spermatozoa}} | {{Oocyte}} | [[Week 1]] | [https://www.ncbi.nlm.nih.gov/pubmed/15316078 PMID 15316078])
===bowel===  
===bowel===  


:(intestine) Term used to describe the midgut and hindgut portion of the gastrointestinal tract running from after the stomach to the anus. Also subdivided into the small bowel ([[S#small intestine|small intestine]]) and the large bowel (large intestine).
:(intestine) Term used to describe the midgut and hindgut portion of the gastrointestinal tract running from after the stomach to the anus. Also subdivided into the small bowel ([[S#small intestine|small intestine]]) and the large bowel (large intestine).


:(More? [[Gastrointestinal Tract Development]])
:(More? {{Gastrointestinal}})


===Bowen-Conradi syndrome===
===Bowen-Conradi syndrome===
Line 375: Line 416:
:(BCS) A human autosomal recessive genetic disorder characterized by a severe growth failure and psychomotor retardation, leading to death in early childhood. The cause is a mutation in the protein Essential for Mitotic Growth 1 (EMG1, Nep1), a nucleolar protein critical for [[R#ribosome|ribosome]] biogenesis and pre-implantation mouse embryo development.
:(BCS) A human autosomal recessive genetic disorder characterized by a severe growth failure and psychomotor retardation, leading to death in early childhood. The cause is a mutation in the protein Essential for Mitotic Growth 1 (EMG1, Nep1), a nucleolar protein critical for [[R#ribosome|ribosome]] biogenesis and pre-implantation mouse embryo development.


:(More? PMID 20858271)
:(More? [https://www.ncbi.nlm.nih.gov/pubmed/20858271 PMID 20858271])


===Bowman's capsule===
===Bowman's capsule===
:Term describing the cup-shaped double epithelium surrounding the [[G#glomerulus|glomerulus]] of the [[N#nephron|nephron]] within the kidney. The outer parietal layer is a squamous simple epithelium. The inner visceral layer is formed by [[P#podocyte|podocytes]] covering glomerular capillaries. Named after Sir William Bowman (1816 - 1892), an English physician and physiologist.
:Term describing the cup-shaped double epithelium surrounding the [[G#glomerulus|glomerulus]] of the [[N#nephron|nephron]] within the kidney. The outer parietal layer is a squamous simple epithelium. The inner visceral layer is formed by [[P#podocyte|podocytes]] covering glomerular capillaries. Named after Sir William Bowman (1816 - 1892), an English physician and physiologist.


:(More? [[Renal System Development]] | [[Renal_System_Histology|Renal Histology]])
:(More? {{Renal}} | [[Renal_System_Histology|Renal Histology]])


===BPD===  
===BPD===  
Line 386: Line 427:
:Acronym for '''b'''i'''p'''arietal '''d'''iameter, measurement between the 2 sides of the head, used in clinical [[U#ultrasound|ultrasound]] measurements after 13 weeks.  
:Acronym for '''b'''i'''p'''arietal '''d'''iameter, measurement between the 2 sides of the head, used in clinical [[U#ultrasound|ultrasound]] measurements after 13 weeks.  


:(More? [[Ultrasound]])
:(More? {{Ultrasound}})


===Brachet's cleft===
===Brachet's cleft===
:A visible cleft separates mesendoderm and ectoderm that appears during early gastrulation. This region is also a fibronectin-rich extracellular matrix that generates a [[C#chordin|Chordin]], secreted by the dorsal Spemann organiser, morphogen gradient.
:A visible cleft separates mesendoderm and {{ectoderm}} that appears during early gastrulation. This region is also a fibronectin-rich extracellular matrix that generates a [[C#chordin|Chordin]], secreted by the dorsal Spemann organiser, morphogen gradient.


:(More? [[Frog Development]] [[Gastrulation]] PMID 24284174)
:(More? {{Frog}} | {{Gastrulation}} | [https://www.ncbi.nlm.nih.gov/pubmed/24284174 PMID 24284174])
[[File:Gray0807.jpg|thumb|150px|alt=brachial plexus|link=Neural_-_Spinal_Cord_Development#Brachial_Plexus|brachial plexus]]
===brachial plexus===  
===brachial plexus===  


:(Latin, ''bracchium'' = arm) The mixed spinal nerves innervating the upper limb form a complex meshwork (crossing).
:(Latin, ''bracchium'' = arm) The mixed spinal nerves innervating the upper limb form a complex meshwork (crossing). Formed by union of the anterior divisions of the lower 4 cervical nerves and the greater part of the anterior division of the first thoracic nerve.


:(More? [[Neural System Development]])
:(More? [[Neural_-_Spinal_Cord_Development#Brachial_Plexus|Brachial Plexus]] | [[Neural System Development]])


===brachiocephalic trunk===  
===brachiocephalic trunk===  
Line 404: Line 446:
:(More? [[Lecture - Early Vascular Development]] | [[Cardiovascular System Development]])
:(More? [[Lecture - Early Vascular Development]] | [[Cardiovascular System Development]])


===bradycardia===
:Clinical term for a slow heart rate. In fetal heart monitoring for the term fetus, this is defined as a heart rate of less than 110 beats per minute.
:(More? [[Cardiovascular_System_-_Heart_Rate_Development|Fetal Heart Rate]] | [[Fetal Development]]
[[File:Brain fissure development 03.jpg|thumb|150px|alt=Brain fissure development|link=Neural_System_Development|Brain fissure development]]
===brain===  
===brain===  


Line 410: Line 457:
:(More? [[Neural System Development]])
:(More? [[Neural System Development]])


[[File:Stage14 sem2l.jpg|thumb|150px|alt=pharyngeal arch|link=Head_Development|Pharyngeal arches human embryo (week 5)]]
===branchial arch===  
===branchial arch===  


Line 430: Line 478:
:([[P#pharyngeal arch pouch|pharyngeal arch pouch]], Greek, ''branchial'' = gill) See [[P#pharyngeal arch pouch|pharyngeal arch pouch]].
:([[P#pharyngeal arch pouch|pharyngeal arch pouch]], Greek, ''branchial'' = gill) See [[P#pharyngeal arch pouch|pharyngeal arch pouch]].


[[File:Galletti1770 breech 01.jpg|thumb|150px|alt=Breech Birth Position|link=Birth|Breech birth position]]
===breech===  
===breech===  


Line 441: Line 490:


:(More? [[Spermatozoa Development]] | [[Week 1]])
:(More? [[Spermatozoa Development]] | [[Week 1]])
===Brenner hypothesis===
:A clinical renal hypothesis that states, individuals with a congenital reduction in nephron number have a much greater likelihood of developing adult hypertension and subsequent renal failure. Developed in the 1980's by [https://nephrology.ucsf.edu/about/hist-brenner.html Barry Brenner] at the Brigham and Women's Hospital, this also fits with the [Abnormal Development - Developmental Origins of Health and Disease|DOHAD hypothesis].
:(More? [[Renal System Development|Renal Development]] | {{DOHAD}} | [https://www.ncbi.nlm.nih.gov/pubmed/3063284 PubMed 3063284] | [https://nephrology.ucsf.edu/about/hist-brenner.html Barry Brenner])


===Brn3a===
===Brn3a===
Line 452: Line 507:
:Human female genital tract mesentery formed by a double fold of [[P#peritoneum|peritoneum]] that connects the [[U#uterus|uterus]] to the peritoneal floor and walls. Anatomically it has three parts: [[M#mesometrium|mesometrium]] (surrounding the [[U#uterus|uterus]]), [[M#mesosalpinx|mesosalpinx]] (surrounding the uterine tube) and [[M#mesovarium|mesovarium]] (surrounding the [[O#ovary|ovary]]).  
:Human female genital tract mesentery formed by a double fold of [[P#peritoneum|peritoneum]] that connects the [[U#uterus|uterus]] to the peritoneal floor and walls. Anatomically it has three parts: [[M#mesometrium|mesometrium]] (surrounding the [[U#uterus|uterus]]), [[M#mesosalpinx|mesosalpinx]] (surrounding the uterine tube) and [[M#mesovarium|mesovarium]] (surrounding the [[O#ovary|ovary]]).  


:(More? [[Genital_-_Female_Development|Genital System - Female]])
:(More? {{Female}})


===bronchi===
===bronchi===
Line 458: Line 513:
:(Latin, ''bronchos'' = windpipe) Plural of bronchus, the two subdivisions of the trachea carrying air to the lungs. Embryologically forms as an endodermal outpocket of the foregut which branch (bronchiole, subdivision of the bronchus) as they grow.  
:(Latin, ''bronchos'' = windpipe) Plural of bronchus, the two subdivisions of the trachea carrying air to the lungs. Embryologically forms as an endodermal outpocket of the foregut which branch (bronchiole, subdivision of the bronchus) as they grow.  


:(More? [[Respiratory System Development]])
:(More? {{Respiratory}})


===bronchiole===
===bronchiole===
Line 464: Line 519:
:(Latin, ''bronchos'' = windpipe) A smaller branch subdivision of the respiratory tract [[B#bronchus|bronchus]].
:(Latin, ''bronchos'' = windpipe) A smaller branch subdivision of the respiratory tract [[B#bronchus|bronchus]].


:(More? [[Respiratory System Development]] | [[Lecture - Respiratory Development]])
:(More? {{Respiratory}} | [[Lecture - Respiratory Development]])


===bronchopulmonary dysplasia===
===bronchopulmonary dysplasia===
Line 470: Line 525:
:A heterogeneous lung disease seen in preterm (premature) infants and diagnosed within the first months of life. Condition was first described in 1967.
:A heterogeneous lung disease seen in preterm (premature) infants and diagnosed within the first months of life. Condition was first described in 1967.


:(More? [[Birth_-_Preterm|Preterm Birth]])
:(More? {{Preterm birth}})


===bronchus===
===bronchus===
Line 476: Line 531:
:(Latin, ''bronchos'' = windpipe) The individual division of the [[T#trachea|trachea]] carrying air to the lungs. Develops as an endodermal outpocket of the foregut which branch repeatedly as they grow (bronchiole, subdivision of the bronchus).  
:(Latin, ''bronchos'' = windpipe) The individual division of the [[T#trachea|trachea]] carrying air to the lungs. Develops as an endodermal outpocket of the foregut which branch repeatedly as they grow (bronchiole, subdivision of the bronchus).  


:(More? [[Respiratory System Development]] | [[Lecture - Respiratory Development]])
:(More? {{Respiratory}} | [[Lecture - Respiratory Development]])
 
[[File:Brown adipose histology.jpg|thumb|150px|alt=Brown adipose histology|link=Adipose Tissue Development|Brown adipose histology]]
===brown adipose===  
===brown adipose===  


:(brown fat) Neonatal specialized form of adipose tissue used in mammals to generate body temperature (thermogenic organ) by non-shivering thermogenesis. Adult fat (white adipose) cannot be used in this fashion. This form of adipose tissue is also seen in animals that hibernate.  
:(brown fat) Neonatal specialized form of adipose tissue used in mammals to generate body temperature (thermogenic organ) by non-shivering thermogenesis. Adult fat (white adipose) cannot be used in this fashion. This form of adipose tissue is also seen in animals that hibernate.  


:(More? [[Musculoskeletal System Development]] | [[Integumentary System Development]])
:(More? [[Adipose Tissue Development]] | [[Birth]] | [[Musculoskeletal System Development]] | [[Integumentary System Development]])


===Bruce effect===  
===Bruce effect===  
Line 500: Line 555:
:(Latin, ''bucca'' = cheek) A term used to relate to the mouth (oral cavity).  
:(Latin, ''bucca'' = cheek) A term used to relate to the mouth (oral cavity).  


:(More? [[Gastrointestinal Tract Development]])
:(More? {{Gastrointestinal}} )


===buccopharyngeal membrane===  
===buccopharyngeal membrane===  


:(oral membrane; Latin, ''bucca'' = "cheek") A membrane which forms the external upper membrane limit (cranial end) of the early gastrointestinal tract (GIT). This membrane develops during gastrulation by [[E#ectoderm|ectoderm]] and [[E#endoderm|endoderm]] without a middle (intervening) layer of [[M#mesoderm|mesoderm]]. The membrane lies at the floor of the ventral depression (stomadeum) where the oral cavity will open and will breakdown to form the initial "oral opening" of the gastrointestinal tract. The equivilent membrane at the lower end of the gastrointestinal tract is the [[C#cloacal_membrane|cloacal membrane]].  
:(oral membrane; Latin, ''bucca'' = "cheek") A membrane which forms the external upper membrane limit (cranial end) of the early gastrointestinal tract (GIT). This membrane develops during gastrulation by {{ectoderm}} and [[E#endoderm|endoderm]] without a middle (intervening) layer of [[M#mesoderm|mesoderm]]. The membrane lies at the floor of the ventral depression (stomadeum) where the oral cavity will open and will breakdown to form the initial "oral opening" of the gastrointestinal tract. The equivilent membrane at the lower end of the gastrointestinal tract is the [[C#cloacal_membrane|cloacal membrane]].  


:(More? [[Gastrointestinal Tract Development]] | [[Head Development]] | [[Lecture - Gastrointestinal Development]])
:(More? [[Gastrointestinal Tract Development]] | [[Head Development]] | [[Lecture - Gastrointestinal Development]])
[[File:Tooth bud stage.jpg|thumb|150px|alt=tooth bud stage|link=Integumentary System - Tooth Development|bud stage]]
===bud stage===
:Tooth stage development occurring after placode and before cap stage. At the sites of the dental placodes the epithelial cells proliferate and intrude within the mesenchyme forming the tooth buds. At this developmental stage the odontogenic potential is lost form the epithelium and granted to the ectomesenchyme.
{{Tooth stages}}
:(More?  [[Integumentary System - Tooth Development|Tooth Development]])


===bulbourethral gland===  
===bulbourethral gland===  
Line 513: Line 576:


:(More? [[Lecture - Genital Development]] | [[Genital System Development]])
:(More? [[Lecture - Genital Development]] | [[Genital System Development]])
 
[[File:Outflow Tract Division (Cross-Section).jpg|thumb|150px|alt=heart bulbar ridges|link=Intermediate - Outflow Tract|Heart bulbar ridges]]
===bulbar ridge===
===bulbar ridge===
:Term describing a spiral region in the developing heart bulbus cordis, there is a left and right bulbar ridge, that contribute to the septation of membranous portion of ventricular septum that is continuous with the outflow tract. These regions fuse to separate the single embryonic outflow tract into the aortic and pulmonary arteries.
:Term describing a spiral region in the developing heart bulbus cordis, there is a left and right bulbar ridge, that contribute to the septation of membranous portion of ventricular septum that is continuous with the outflow tract. These regions fuse to separate the single embryonic outflow tract into the aortic and pulmonary arteries.


:(More? [[Advanced_-_Cardiac_Septation|Heart Tutorial]] | [[Ventricular_Septum_Movie_1|Ventricular Septum Movie]] | [[Heart Outflow Septation Movie]] | [[Cardiovascular System Development]] | [[Lecture - Heart Development]])
:(More? [[Advanced_-_Cardiac_Septation|Heart Tutorial]] | [[Ventricular_Septum_Movie_1|Ventricular Septum Movie]] | [[Heart Outflow Septation Movie]] | [[Cardiovascular System Development]] | [[Lecture - Heart Development]])
 
[[File:Heart Tube Segments.jpg|thumb|150px|alt=Heart bulbus cordis|link=Cardiovascular System Development|Heart bulbus cordis]]
===bulbus cordis===  
===bulbus cordis===  



Latest revision as of 09:16, 24 January 2020

Embryology - 29 Mar 2024    Facebook link Pinterest link Twitter link  Expand to Translate  
Google Translate - select your language from the list shown below (this will open a new external page)

العربية | català | 中文 | 中國傳統的 | français | Deutsche | עִברִית | हिंदी | bahasa Indonesia | italiano | 日本語 | 한국어 | မြန်မာ | Pilipino | Polskie | português | ਪੰਜਾਬੀ ਦੇ | Română | русский | Español | Swahili | Svensk | ไทย | Türkçe | اردو | ייִדיש | Tiếng Việt    These external translations are automated and may not be accurate. (More? About Translations)

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

B

B-Myb

A protein transcription factor and a member of the A-Myb, B-Myb (MybL2) and C-Myb family found in all proliferating cells. B-Myb is the only member of this Myb family specific to embryonic stem cells and is required for both cycle progression and mitotic spindle formation. In mice, lack of the gene leads to early embryonic death, after implantation due to defects on the inner cell mass.

Babinski reflex

(Babinski sign, plantar reflex) Clinical term describing a primitive reflex, an involuntary response (reflex) that is present at birth and that normally disappears between 12 to 24 months. The reflex occurs when the sole of the foot has been firmly stroked the big toe moves toward the top of the foot and the other toes fan out. It is present in the newborn as the myelination of the corticospinal tracts has not yet been completed. Postnatal persistence (beyond 24 months or 2 years) occurs in infants with damage to the corticospinal tract.
(More? Neural Exam - Newborn reflexes - plantar reflex | Neural System Development | Neonatal Development | Medline Plus - Babinski's reflex)

bacteria

(bacterium, Greek, bakterion = little rod) A unicellular prokaryote cell, which exist in many different genetic and structural forms in many environments including commisural bacteria in the gastrointestinal tract and are also the cellular cause of infection.
(More? bacteria)

bacterial spore

(bacterium, Greek, bakterion = little rod) An inactive and hardy form of bacteria, similar in function to a fungal spore that can survive in a metabolically dormant state for many years and can also withstand high temperatures, radiation, and toxic chemicals.
(More? bacteria)
Bacterial vaginosis
Bacterial vaginosis (gram-stained vaginal smear)

bacterial vaginosis

(BV, vaginitis) Clinical condition associated with loss of vaginal lactobacilli such as Lactobacillus acidophilus, Lactobacillus crispatus and Lactobacillus jensenii, and acquisition of complex communities of anaerobic bacteria such as species of Streptococcus. A common condition, USA about 29% of reproductive age women. Can result in an increased risk for pre-term birth, HIV-1 acquisition and pelvic inflammatory disease.
(More? Abnormal Development - Bacterial Infection)

bacteriophage

(Greek, bakterion = little rod + phagein = to eat) or phage A virus that infects bacteria.
(More? Abnormal Development - Bacterial Infection)
Oocyte bambini body
Oocyte Balbiani body

Balbiani body

(mitochondrial cloud) collection of cell organelles (mitochondria, endoplasmic reticulum, and granulofibrillar material) asymmetrically located beside the nucleus in very young oocytes in some species. Appears similar to germinal granule precursors seen some species that contain a definitive germ plasm (flies, worms, and frogs). Dynamic region involved in early cell polarity and RNA localisation in the oocyte. Named after Edouard-Gérard Balbiani (1823 – 1899) a French biologist who was among the first to describe them.
(More? EM Image | Oocyte Development | E. Balbiani | PMID 15654016)

Ballottement

(French, ballottement = "a tossing about") Clinical palpatory test (clinical week 6 - 20) used to detect pregnancy, when the lower uterine segment (or cervix) is tapped by examiner's finger, the fetus floats upward, then sinks again and can be felt on the finger. Not considered diagnostic as it can also be elicited in the presence ovarian cysts.

Bardet-Biedl syndrome

(BBS) is an abnormality with triallelic inheritance and is characterized by a rangne of multisystem abnormalities (cone-rod dystrophy, truncal obesity, postaxial polydactyly, cognitive impairment, neural development, male hypogonadotrophic hypogonadism, complex female genitourinary malformations, and renal dysfunction).
(More? Sensory - Vision Abnormalities | Genital System - Abnormalities | OMIM - Bardet-Biedl syndrome | GeneReviews - Bardet-Biedl syndrome)

Barker Hypothesis

(Developmental Origins of Health and Disease, DOHaD, Fetal Origins Hypothesis) Term named after the researcher, Barker who began a statistical analysis in the UK, of low birth weight data (early 1900's). The hypothesis has since been renamed as the Fetal Origins Hypothesis and proposes that in utero influences can lead too permanent changes in embryo/fetus, low birth weight, which predisposes to chronic disease in adult life.
(More? Developmental Origins of Health and Disease)

Barlow test

(Barlow maneuver) A clinical term to describe a physical examination of the newborn for developmental dysplasia of the hip (DDH). The examiner adducts the hip (bringing the thigh towards the midline) while applying light pressure on the knee, directing the force posteriorly. A positive sign is the hip being dislocatable, if the hip can be popped out of socket with this test. This test is then combined with the Ortolani test (maneuver). The test is named after Thomas Barlow (1845 – 1945) a British royal physician.
(More? Musculoskeletal System Development | Postnatal Development | Screening for developmental dysplasia of the hip: recommendation statement. PMID 16510673)
Barr body
Barr body (human female neutrophil)

Barr body

Name given to a visible cellular feature at the periphery of the nucleus, produced by the inactivation of a single X chromosome in females. Named after Murray Barr (1908 – 1995), a Canadian physician and medical researcher who first identified this cellular structure.
(More? X Inactivation | PMID 18120749)

Barth syndrome

(BS) Rare X-linked infantile-onset cardioskeletal disease characterized by cardiomyopathy, hypotonia, growth delay, neutropenia and 3-methylglutaconic aciduria. It is caused by mutations in the TAZ gene encoding tafazzin, a protein involved in the metabolism of cardiolipin, a mitochondrial-specific phospholipid involved in mitochondrial energy production.
(More? Cardiovascular Abnormalities | OMIM 302060 | GHR - tafazzin PMID 23409742)

Bartholin gland

(greater vestibular gland) A pair of female external genital tract glands which secretes mucus to lubricate the vagina. The equivalent male gland is the Bulbourethral Gland or Cowper's Gland.
(More? Lecture - Genital Development | Genital - Female Development)

basal body

The base of an axoneme; a cylinder about 500 nm long that resembles a centriole; the microtubule organizing center of a cilium or a eukaryotic flagellum.

basal body temperature

(bbt) The temperature taken at its lowest point in the day, typically in the morning before getting out of bed. Note that body temperature changes, an increase, is used to approximately establish the time of ovulation.
(More? Menstrual Cycle | Abnormal Development - Maternal Hyperthermia)

basal ganglia

(basal nuclei) A central nervous system (CNS) neural structure derived embryologically from the secondary vesicle telencephalon (endbrain) and the earlier primary vesicle prosencephalon (forebrain) from the neural tube. Structurally, it connects the cerebral cortex with the thalamus and brainstem and is associated with motor control and learning.
(More? Neural - Basal Ganglia Development | ectoderm | Neural System Development)
basal plate
basal plate

basal plate

The early neural tube forms into two thicker lateral regions, the basal plate and alar plate, which separate the floor plate and roof plate regions. They are divided within the lateral wall of the tube by an indentation called the sulcus limitans. The basal plate forms the ventral lateral region of the developing neural tube. At the level of the spinal cord, this region will form the motor ventral horn region.
(More? spinal cord | neural | Dev Biol Development of the human spinal cord)

base

Another term for a nucleotide (usually a t c g) that forms deoxyribonucleic acid (DNA).
(More? genetics)

base pair

Double stranded DNA has nucleotides A-T, C-G, paired by hydrogen bonds (2 bonds for AT, 3 bonds for GC). Note this means that GC is harder to separate that AT.
(More? genetics)

basket cells

Central nervous system cerebellar interneurons located in the cerebellum molecular layer. These GABAergic neurons, and stellate cells, receive an excitatory synaptic input from granule cell axons (parallel fibers) and form an inhibitory synapse with Purkinje cells. The embryonic progenitors arise from the neuroepithelium at the level of of the fourth ventricle.
(More? cerebellum | ectoderm | PMID 19500566)

basonuclin 2

(bnc2, BNC2) A vertebrate zinc finger transcription factor that has a role in the proliferation of craniofacial mesenchymal cells and therefore in head and face development. (ortholog of drosophila disco proteins)
(More? PMID 16891417)

battledore placenta

(placenta battledore, batyldoure = a beating instrument) A term describing a placenta where the umbilical cord is attached at the margin. Occurs 7- 9% in singleton pregnancies and 24-33% in twin pregnancies and may effect placental function/fetal growth. The description probably comes from the similarity to a bat or paddle.
(More? placenta abnormalities | Placenta Development)

Bayley Scales of Infant Development

(BSID) A postnatal (from 1 to 42 months) neurological assessment scale used in screening and diagnosis of development using 178 item mental scale and the 111 item motor scale, the original BSID was revised in 1993 to version 2 (BSID-II). THere are several alternative assessments tests and tasks including: Alberta Infant Motor Scale (AIMS), Fagan Test of Infant Intelligence (FTII), Peabody Developmental Motor Scale II (PDMS-2) Comprehensive Developmental Inventory for Infants and Toddlers (CDIIT), Means-End Problem-Solving Task, Operant Discrimination Learning, Mobile/Train Conjugate Reinforcement Tasks, The Transparent Barrier Detour Task, The A-not-B Task
(More? Neural System Development | Neonatal Development - Postnatal Neural)

Becker muscular dystrophy

(BMD) A muscle degenerative disorder, similar to Duchenne muscular dystrophy (DMD), but allows muscles to function better than in DMD, slower progression, make a shortened form of the mutated protein. Named after Peter Emil Becker, a German doctor who first described this variant in the 1950s. PMID 13249581
(More? becker muscular dystrophy | PMID 13249581)
tooth bell stage
bell stage

bell stage

Tooth stage development occurring after cap stage and before terminal differentiation. The cap folds in and acquires the form of a bell, secondary enamel knots appear.
Tooth stages: lamina | placode stage | bud stage | cap stage | bell stage | all stages | Tooth Development
(More? Tooth Development)

beta-catenin

(β-Catenin) See catenin.
(More? Developmental Signals - Wnt‎)

beta cell

Endocrine cells located in the pancreas (pancreatic islets, islets of Langerhans) that secrete insulin and increase glucose uptake. In development, their secretion stimulates fetal growth and the cells continue to proliferate to postnatal, in infancy most abundant. There are 4 different endocrine cell types (alpha, beta, delta, F-cells) in each pancreatic islet. Loss of these cells is associated with diabetes.
(More? pancreas | Maternal Diabetes)

beta-thalassemia

A group of hereditary blood disorders caused by anomalies in the synthesis of the beta chains of haemoglobin, resulting in variable phenotypes from severe anemia to clinically asymptomatic individuals. Total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union.
(More? Genetic Abnormalities | cardiovascular | PMID 20492708)

bicornuate uterus

("heart-shaped" uterus) Female uterus (internal genital tract) abnormality, where the paramesonephric ducts (Mullerian ducts) fail to completely fuse forming two separate body parts that fuse close to the opening into the vagina.
(More? Uterus Development | Lecture - Genital Development | Genital System - Abnormalities)
bilaminar embryo
bilaminar embryo

bilaminar embryo

(two layer embryo) Term used in early embryonic development to describe the inner cell mass differentiating to form an initial two layered structure (epiblast and hypoblast). In human development, this occurs during week 2. The epiblast layer will then form the majority of the embryo replacing the hypoblast during gastrulation during week 3.

bile salts

(conjugated bile alcohols and bile acids) Liver synthesized compounds derived from cholesterol that function postnatally in the small intestine to solubilize and absorb lipids, vitamins, and proteins. These compounds act as water-soluble amphipathic detergents.
(More? Liver Development | Gastrointestinal Tract Development | Lecture - Gastrointestinal Development)

biliary cells

The liver epithelial cell formed from hepatoblast differentiation (hepatoblasts form initially from endoderm).
(More? Liver Development | Gastrointestinal Tract Development | Lecture - Gastrointestinal Development)

Billings Method

See Billings Ovulation Method.

Billings Ovulation Method

(BOM, Billings Method, Ovulation Method, rhythm method, Natural Family Planning) A self-observation method for women use to monitor their fertility. Used by women trying to either avoid pregnancy or trying to conceive. Named after John Billings and Evelyn Billings, two Australian doctors. Evelyn Billings co-authored the original book "The Billings Method" (1980) with Dr Ann Westmore, recently republished.
(More? Menstrual Cycle | Fertilization | 2011 edition | Billings LIFE | PMID 4117608)

biopsy

A fragment of tissue removed for (clinical/pathological/medical) study under the microscope.

biotinidase

An enzyme required to free biotin from its bound form for use. Biotinidase deficiency can be detected in newborn screening and treated with daily biotin supplementation.
(More? Guthrie test)

biotinidase deficiency

Term used to classify a group of metabolic disorders which disrupt normal amino acid metabolism, particularly branched-chain amino acids, causing a buildup of acids which are usually not present. Multiple carboxylase deficiency (MCD) is an autosomal recessive metabolic disorder characterized primarily by cutaneous and neurologic abnormalities. Symptoms result from the inability to reutilize biotin, a necessary nutrient.
 ICD-11 5C50.E Organic aciduria - 5C50.E0 Classical organic aciduria
(More? Guthrie test)

biparietal diameter

An ultrasound measurement of Biparietal Diameter (BPD) is used to determine fetal age and normal development (small/large/abnormal) parameters. Measured as the diameter between the 2 sides of the head, used in clinical ultrasound measurements after 13 weeks (2.4 cm) to term (9.5 cm). It is one of the four typical ultrasound assessments of fetal size and age: Biparietal Diameter (BPD), Head Circumference (HC), Abdominal Circumference (AC), and Femur Length (FL).
(More? ultrasound | head)
Birth MRI
Birth MRI

birth

(parturition) Term describing the physiological process of offspring (child) being born.
(More? birth)

birth rate

A statictical term typically calculated by dividing the number of live births in a population in a year by the mid-year resident population.
(More? birth | Australia’s mothers and babies 2015 | Statistics)

Bishop score

(Bishop's score) A clinical test prior to birth named after the obstetrician/gynaecologist Edward H. Bishop (1913-1995) who published a 1964 paper "Pelvic Scoring For Elective Induction". PMID 14199536
(More? birth | PMID 14199536 | 1995 In Memoriam)
Urinary Bladder (week 8)
Urinary Bladder (week 8)

bladder

(urinary bladder) The simplified term used to describe the urinary bladder muscular sac for the storage of urine.
(More? Bladder Development | renal | Lecture - Renal Development)

bladder exstrophy

(Greek, ekstriphein = "turn inside out") A congenital malformation with urinary bladder open to ventral wall of abdomen (between umbilicus and pubic symphysis) and may have other anomolies associated with failure of closure of abdominal wall and urinary bladder (epispadias, pubic bone anomolies).
(More? renal abnormalities)

blastema

Term used to describe an undifferentiated mass of cells, for example in Wilm's tumour.
(More? Wilm's tumour)
Blastocoel
Blastocoel

blastocoel

(blastocoele, blastocele) A fluid-filled cavity that forms in early development within the blastocyst. Initially the dividing cells form a solid cellular mass (morula) continued cell division and compaction lead to the formation of this space or cavity. In humans, this cavity is present during the end of the first week and into the second week of development.
(More? Week 1 | Week 2 | blastocyst)

blastocyst

(Greek, blastos = sprout + cystos = cavity) Term used to describe the hollow cellular mass that forms in early development. The blastocyst consists of cells forming an outer trophoblast layer, an inner cell mass and a fluid-filled cavity. The blastocyst inner cell mass is the source of true embryonic stem cells capable of forming all cell types within the embryo. In humans, this stage occurs in the first and second weeks after the zygote forms a solid cellular mass (morula stage) and before implantation.
(More? blastocyst | Week 2 | Stem Cells)
blastocyst hatching
Blastocyst Hatching (day 5)

blastocyst biopsy

An Assisted Reproductive Technology preimplantation genetic diagnosis technique carried out at blastocyst stage (day 4-5), removes several trophoblast (trophoderm) cells, detects chromosomal abnormalities of both maternal and paternal origin and may detect cellular mosaicism.
(More? Assisted Reproductive Technology | Preimplantation Genetic Diagnosis | zygote | morula | Week 1 | Genetic Abnormalities)

blastocyst hatching

(Greek, blastos = sprout + cystos = cavity) Term used to describe the process of blastocyst emerging from the surrounding protective zona pellucida. In human development this process occurs at the end of the first week (day 5-7) GA week 3. The location of hatching from the ZP can occur at the original spermatozoa entry site for fertilisation, and must complete before implantation can commence.
(More? blastocyst | Blastocyst Hatching Movie | implantation)
Human Embryo (day 2) 4 blastomere
Human Embryo (day 2) 4 blastomeres

blastomeres

Term used to describe the first cells formed by mitotic cell division of the zygote.
(More? zygote | morula | Week 1)

blastomere biopsy

An Assisted Reproductive Technology preimplantation genetic diagnosis technique carried out at cleavage stage (day 3), excluding poor quality embryos, detects chromosomal abnormalities of both maternal and paternal origin. May not detect cellular mosaicism in the embryo.
(More? Assisted Reproductive Technology | Preimplantation Genetic Diagnosis | zygote | morula | Week 1 | Genetic Abnormalities)

blastopore

The opening formed by the gastrulating cell migration in early blastula to gastrula development.
(More? Week 2 | Week 3 | frog)

blastula

(Greek, blastos = sprout = little sprout) A stage of an animal embryo that consists of a fluid-filled sphere of cells on the surface. In mammals, blastulation leads to the formation of the blastocyst, which should not be confused with the blastula. The blastocyst contains an inner embryoblast (inner cell mass), which is homologous to the blastula. However, it also includes the trophoblast, which goes on to form the extraembryonic tissues.
morula -> blastula -> gastrula
(More? blastocyst | Week 1)

blighted ovum

(missed abortion, early fetal loss) A historic term now called replaced by early fetal loss, describing embryo loss that occurs in first trimester.

BLIMP1

DNA-binding transcriptional repressor (zinc-finger) which has a role in both embryo development and adult tissues by regulating (repressing) p53 expression allowing normal cell growth.
(More? PMID 17264218)

blood islands

The initial small patches which form within mesoderm that differentiate into both the blood vessel wall and blood cells. These islands enlarge and connect together to form the initial vascular beds.
(More? blood | Lecture - Early Vascular Development)

blood-brain barrier

(BBB) The barrier formed at the cellular level by endothelial cells of brain capillaries, differing in junctions, transport and glial association from those found in peripheral capillaries. Damage to this barrier can occur following injuries involving ischemia and reperfusion.
(More? neural | cardiovascular)

blood-testis barrier

(BTB) In the testis this barrier is formed by tight junctions, basal ectoplasmic specializations, desmosome-like junctions and gap junctions between adjacent Sertoli cells near the basement membrane of the seminiferous epithelium. Historically referred to as a "barrier" as intravenous dyes in rodents failed to ‘stain’ the seminiferous tubules in the testis as well as in the brain, the blood-brain barrier (BBB).
(More? testis | spermatozoa | PMC2804914)

blueberry muffin baby

Term used historically by paediatricians to describe the appearance of newborns infected with rubella during the American epidemic of the 1960s.
(More? Abnormal Development - Rubella Virus)

BMI

Acronym for Body Mass Index which is a measure of body composition. Used to determine adiposity, that is fat content, which has influences upon growth and health.

Bmi1

A proto-oncogene protein located in the nucleus, which is a member of the Polycomb-group gene family (required to maintain the repression of homeotic genes). Expressed in range of stem cells including hematopoietic, neural and intestinal stem cells. Human BMI-1 gene on the short arm of chromosome 10 (10p13). PMID: 18536716
(More? gastrointestinal | OMIM - proto-oncogene BMI-1)

BOC

Acronym for Brother of Cdon a cell surface receptor. CDON is also a acronym for Cell adhesion molecule-regulated/downregulated by oncogenes. Both Boc and Cdon are cell surface receptors (for sonic hedgehog) of the immunoglobulin (Ig)/fibronectin type III that interact with each other, are coexpressed and involved in neural and muscle development.
(More? Developmental Signals - Sonic hedgehog | OMIM - BROTHER OF CDON)

Bochdalek hernia

The most common form (80-85%) of the Congenital Diaphragmatic Hernia (CDH) types occurring mainly on the postero-lateral (left) side of the respiratory diaphragm. Due to the pleuroperitoneal foramen (foramen of Bochdalek) failing to developmentally close allowing visceral organs to enter the pleural cavity. The less common CDH form is the Morgagni hernia (through the foramen of Morgagni) occurring beside the xiphoid process of the sternum. CDH is a musculoskeletal defect which impacts upon respiratory development and function.
(More? Congenital Diaphragmatic Hernia | Medline Plus - CDH)

body mass index

(BMI) The most commonly used method of assessing whether a person is normal weight, underweight, overweight or obese. It is calculated by dividing the person’s weight (in kilograms) by their height (in metres) squared. For both adult men and women, underweight is a BMI below 18.5, acceptable weight is from 18.5 to less than 25, overweight is 25 and above (includes obese), and obese is 30 and over.

body-stalk

(connecting stalk) Historic term used to describe the early extra-embryonic mesoderm region connecting the embryonic disc to the chorion. Present mainly in week 3 of human development, this region will later form the placental cord region, becomes vascular, and connect the embryo to the placenta.
(More? Fig. 25. early formation of body-stalk | Week 3 | Placenta Development)

bombesin receptor

A cell receptor family associated mainly with gastrointestinal function (motility and secretion) and neural functions (circadian rhythm, thermoregulation anxiety/fear responses, food intake). In mammals, these G protein-coupled receptors are: neuromedin B, gastrin-releasing peptide, and orphan receptor bombesin receptor subtype 3.
(More? Gastrointestinal Tract Development | Endocrine System Development)
Bone marrow histology
Bone marrow histology

bone

A connective tissue forming the main structural component of the skeleton originating in the body from mesoderm, with some neural crest contribution in the head region. There are two processes of bone formation (ossification): endochondrial, replacing a pre-existing cartilage template (most of the skeleton); or intramembranous, ossification directly from a membrane (cranial vault, scapula). Adult bone gross histology is described as either trabecular bone (also called cancellous or spongy bone) or compact bone (does not have any spaces or hollows).
(More? Bone Development | Musculoskeletal System - Bone Development | Blue Histology - Bone)
bone marrow stromal cells
bone marrow stromal cells

bone marrow

The cellular components found within the core of bones, mainly long bones, which contain the adult blood stem cell population and a range of other cell types. Generally described as either red marrow (myeloid tissue) or yellow marrow (mainly fat cells.)
(More? bone | blood | musculoskeletal)

bone marrow stromal cells

(BMSCs) These are pluripotental cells from bone marrow that can potentially differentiate into a range of connective tissue and muscle cell types (cardiomyocytes, rhabdomyocytes, hepatocytes, osteocytes, chondrocytes, tencoytes, adipocytes, smooth muscle cells). These cells have therefore been seen as a source of stem cells for tissue repair.
(More? bone | blood | musculoskeletal)
borrelia burgdorferi
borrelia burgdorferi

borrelia burgdorferi

(B. burgdorferi) The agent of Lyme disease in North America and Europe. A species of bacteria of the spirochete class of the genus Borrelia.
(More? Abnormal Development - Bacterial Infection)
Botallo's duct
Botallo's duct

Botallo's duct

(ductus arteriosus, ligamentum arteriosum, ductus Botallo, ductus Botalli) A vascular shunt between pulmonary trunk and the aortic arch. This channel degenerates to form the ligamentum arteriosum (ligamentum Botalli). In preterm infants this channel may remain open as a patent ductus arteriosus. Named after Leonardo Botallo an Italian surgeon in Paris (1530-1600).
(More? Patent Ductus Arteriosus | Cardiovascular System Development | Birth)

bouquet stage

Meiosis term used to describe in prophase the chromosome telomeres attachment to the inner nuclear envelope and form a cluster. This occurs before the onset of homologous pairing and synapsis. The name comes from the chromosomes resembling a "bouquet of flowers", observed in all organisms except worms (caenorhabditis elegans) and flies (drosophila).
(More? meiosis | spermatozoa | oocyte | Week 1 | PMID 15316078)

bowel

(intestine) Term used to describe the midgut and hindgut portion of the gastrointestinal tract running from after the stomach to the anus. Also subdivided into the small bowel (small intestine) and the large bowel (large intestine).
(More? gastrointestinal)

Bowen-Conradi syndrome

(BCS) A human autosomal recessive genetic disorder characterized by a severe growth failure and psychomotor retardation, leading to death in early childhood. The cause is a mutation in the protein Essential for Mitotic Growth 1 (EMG1, Nep1), a nucleolar protein critical for ribosome biogenesis and pre-implantation mouse embryo development.
(More? PMID 20858271)

Bowman's capsule

Term describing the cup-shaped double epithelium surrounding the glomerulus of the nephron within the kidney. The outer parietal layer is a squamous simple epithelium. The inner visceral layer is formed by podocytes covering glomerular capillaries. Named after Sir William Bowman (1816 - 1892), an English physician and physiologist.
(More? renal | Renal Histology)

BPD

Acronym for biparietal diameter, measurement between the 2 sides of the head, used in clinical ultrasound measurements after 13 weeks.
(More? ultrasound)

Brachet's cleft

A visible cleft separates mesendoderm and ectoderm that appears during early gastrulation. This region is also a fibronectin-rich extracellular matrix that generates a Chordin, secreted by the dorsal Spemann organiser, morphogen gradient.
(More? frog | gastrulation | PMID 24284174)
brachial plexus
brachial plexus

brachial plexus

(Latin, bracchium = arm) The mixed spinal nerves innervating the upper limb form a complex meshwork (crossing). Formed by union of the anterior divisions of the lower 4 cervical nerves and the greater part of the anterior division of the first thoracic nerve.
(More? Brachial Plexus | Neural System Development)

brachiocephalic trunk

(Latin, bracchium = arm, cephalicus = head) The blood vessel forming the first branch of the aortic arch, arises superolaterally and splits into the right subclavian and the right common carotid arteries.
(More? Lecture - Early Vascular Development | Cardiovascular System Development)

bradycardia

Clinical term for a slow heart rate. In fetal heart monitoring for the term fetus, this is defined as a heart rate of less than 110 beats per minute.
(More? Fetal Heart Rate | Fetal Development
Brain fissure development
Brain fissure development

brain

The general term for the central nervous system (CNS) component formed initially from the cranial end of the neural tube. The remainder of the CNS is the spinal cord. The brain forms initially as 3 primary brain vesicles which later form 5 secondary brain vesicles.
(More? Neural System Development)
pharyngeal arch
Pharyngeal arches human embryo (week 5)

branchial arch

(pharyngeal arch, Greek, branchial = gill) See pharyngeal arch.

branchial arch artery

(pharyngeal arch artery, Greek, branchial = gill) See pharyngeal arch artery.

branchial arch cartilage

(pharyngeal arch cartilage, Greek, branchial = gill) See pharyngeal arch cartilage.

branchial arch nerve

(pharyngeal arch nerve, Greek, branchial = gill) See pharyngeal arch nerve.

branchial arch pouch

(pharyngeal arch pouch, Greek, branchial = gill) See pharyngeal arch pouch.
Breech Birth Position
Breech birth position

breech

A birth term where the fetal buttocks are presented first, this can also occur in different forms depending on the fetal structure presentation (complete breech, frank breech, footing breech, knee breech).
(More? Birth | Image Breech Position)

Brek/Lmtk2

Acronym for brain-enriched kinase/lemur tyrosine kinase 2. A signaling protein member of the Aatyk family of kinases, mouse knockouts are infertile with azoospermia.
(More? Spermatozoa Development | Week 1)

Brenner hypothesis

A clinical renal hypothesis that states, individuals with a congenital reduction in nephron number have a much greater likelihood of developing adult hypertension and subsequent renal failure. Developed in the 1980's by Barry Brenner at the Brigham and Women's Hospital, this also fits with the [Abnormal Development - Developmental Origins of Health and Disease|DOHAD hypothesis].
(More? Renal Development | DOHAD | PubMed 3063284 | Barry Brenner)

Brn3a

(POU4F1) A signaling factor of the POU-domain transcription factor class 4, expressed in many developing tissues including sensory neurons and immune B lymphocyte and T lymphocyte lineages and retina (retinal ganglion cells). Recently shown to act as a transcriptional repressor.
(More? Neural Crest Development | OMIM Brn3a | PMID19877281)

broad ligament

Human female genital tract mesentery formed by a double fold of peritoneum that connects the uterus to the peritoneal floor and walls. Anatomically it has three parts: mesometrium (surrounding the uterus), mesosalpinx (surrounding the uterine tube) and mesovarium (surrounding the ovary).
(More? Female)

bronchi

(Latin, bronchos = windpipe) Plural of bronchus, the two subdivisions of the trachea carrying air to the lungs. Embryologically forms as an endodermal outpocket of the foregut which branch (bronchiole, subdivision of the bronchus) as they grow.
(More? respiratory)

bronchiole

(Latin, bronchos = windpipe) A smaller branch subdivision of the respiratory tract bronchus.
(More? respiratory | Lecture - Respiratory Development)

bronchopulmonary dysplasia

A heterogeneous lung disease seen in preterm (premature) infants and diagnosed within the first months of life. Condition was first described in 1967.
(More? preterm birth)

bronchus

(Latin, bronchos = windpipe) The individual division of the trachea carrying air to the lungs. Develops as an endodermal outpocket of the foregut which branch repeatedly as they grow (bronchiole, subdivision of the bronchus).
(More? respiratory | Lecture - Respiratory Development)
Brown adipose histology
Brown adipose histology

brown adipose

(brown fat) Neonatal specialized form of adipose tissue used in mammals to generate body temperature (thermogenic organ) by non-shivering thermogenesis. Adult fat (white adipose) cannot be used in this fashion. This form of adipose tissue is also seen in animals that hibernate.
(More? Adipose Tissue Development | Birth | Musculoskeletal System Development | Integumentary System Development)

Bruce effect

Reproductive change in female mice, pheromones from a strange male can prevent embryo implantation in recently bred female.
(More? Mouse Estrous Cycle)

brucellosis

(Malta fever, Mediterranean fever) A common bacterial zoonotic disease, the human form is transmitted mainly through unpasteurised dairy products derived from infected animals (sheep, goats, cow). Brucella species are small Gram negative coccobacilli, after infection the period of incubation can last from two to eight weeks, and during the first trimester lead to increased rates of spontaneous abortion.
(More? PMID 18162038)

buccal

(Latin, bucca = cheek) A term used to relate to the mouth (oral cavity).
(More? gastrointestinal )

buccopharyngeal membrane

(oral membrane; Latin, bucca = "cheek") A membrane which forms the external upper membrane limit (cranial end) of the early gastrointestinal tract (GIT). This membrane develops during gastrulation by ectoderm and endoderm without a middle (intervening) layer of mesoderm. The membrane lies at the floor of the ventral depression (stomadeum) where the oral cavity will open and will breakdown to form the initial "oral opening" of the gastrointestinal tract. The equivilent membrane at the lower end of the gastrointestinal tract is the cloacal membrane.
(More? Gastrointestinal Tract Development | Head Development | Lecture - Gastrointestinal Development)
tooth bud stage
bud stage

bud stage

Tooth stage development occurring after placode and before cap stage. At the sites of the dental placodes the epithelial cells proliferate and intrude within the mesenchyme forming the tooth buds. At this developmental stage the odontogenic potential is lost form the epithelium and granted to the ectomesenchyme.
Tooth stages: lamina | placode stage | bud stage | cap stage | bell stage | all stages | Tooth Development
(More? Tooth Development)

bulbourethral gland

(Cowper's Gland) A male genital tract gland which secretes a small amount of a thick clear mucous fluid prior to ejaculation, the alkaline content apparently buffers acidity of the urethra. The equivalent female genital tract gland is the greater vestibular gland or Bartholin gland.
(More? Lecture - Genital Development | Genital System Development)
heart bulbar ridges
Heart bulbar ridges

bulbar ridge

Term describing a spiral region in the developing heart bulbus cordis, there is a left and right bulbar ridge, that contribute to the septation of membranous portion of ventricular septum that is continuous with the outflow tract. These regions fuse to separate the single embryonic outflow tract into the aortic and pulmonary arteries.
(More? Heart Tutorial | Ventricular Septum Movie | Heart Outflow Septation Movie | Cardiovascular System Development | Lecture - Heart Development)
Heart bulbus cordis
Heart bulbus cordis

bulbus cordis

A region of the early developing heart tube forming the common outflow tract, will differentiate to form three regions of the heart.
Blood Pathway: sinus venosus -> atrium -> ventricle -> bulbus cordis (outflow tract)
(More? Cardiovascular System Development | Lecture - Heart Development)

bursa

(Latin, bursa = a bag, pouch, purse) Anatomical term describing a closed, fluid-filled sac that functions as a gliding surface to reduce friction between tissues of the body.

bursa omentalis

(omental bursa, lesser sac)

Anatomical term describing the double fold of peritoneum that connects the stomach with other abdominal organs. Formed from an infolding of the greater omentum.


(More? Gastrointestinal Tract Development | Historic)


Glossary Comments

Use this page to access brief definitions of specific embryology terms. Additional information can be accessed from links listed at the end of each definition. Glossary from the UNSW Embryology program compiled and written by Dr Mark Hill. Reference material used in preparing this glossary list includes: texts listed on page 1 "Reading" of each notes section, Department of Anatomy Publications, WWW resources from NCBI, NIH, OMIM, NHMRC (Australia), AMA (USA), Office of Rare Diseases (USA), PubMed Medline Dictionaries, MSDS, Merck Manual home edn. and WHO ART terminology (2009).

These notes are for Educational Purposes Only Please email Dr Mark Hill if you wish to make a comment about this current project.

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

Cite this page: Hill, M.A. (2024, March 29) Embryology B. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/B

What Links Here?
© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G