Talk:Lecture - Musculoskeletal Development

From Embryology

2017

Mark Hill (talk) 11:32, 10 September 2017 (AEST) Reorganised lecture structure for online presentation.

Terms

Bone Terms  
Bone Development
  • canaliculus - (plural, canaliculi) small channel in the bone matrix in which an osteocyte process lies and communicates with other osteocytes and the Haversian canal.
  • cartilage - connective tissue from mesoderm in the embryo forms most of the initial skeleton which is replaced by bone. In adult, found on the surface of bone joints.
  • Cbfa1 - Core-Binding Factor 1 (Runx2) transcription factor protein key to the differentiation of bone OMIM: Cbfa1
  • centrum - the primordium of the vertebral body formed initially by the sclerotome.
  • clavicle - (Latin, clavicle = little key) bone which locks shoulder to body.
  • diaphysis - anatomical term that refers to the shaft of long bones.
  • endochondrial ossification - the process of replacement of the cartilagenous framework by osteoblasts with bone.
  • endosteum - inner layer of cells lining the medullary cavity of long bones and is highly vascularised. A similar cellular region and fibrous layer lies on the outside of the bone, the periosteum.
  • epiphysis - anatomical term that refers to the expanded ends of long bones.
  • extracellular matrix - material secreted by and surrounding cells. Consists if fibers and ground substance.
  • fibroblast growth factors - (FGF) a family of at least 10 secreted proteins that bind membrane tyrosine kinase receptors. A patterning switch with many different roles in different tissues. (FGF8 = androgen-induced growth factor (AIGF)
  • fibroblast growth factor receptor - receptors comprise a family of at least 4 related but individually distinct tyrosine kinase receptors (FGFR1- 4). They have a similar protein structure, with 3 immunoglobulin-like domains in the extracellular region, a single membrane spanning segment, and a cytoplasmic tyrosine kinase domain.
  • haematopoiesis (Greek, haima = "blood"; poiesis = "to make") the process of blood cell formation. In the adult, this occurs only in the bone marrow. In the embryo this occurs in other locations (yolk sac, liver, spleen, thymus) until bone develops.
  • Haversian canal - the central canal of an osteon (Haversian system) in compact bone, within which blood vessels and nerves travel throughout the bone.
  • Haversian system - (osteon) the historic name for the functional unit of compact bone. Consists of a central canal (Haversian canal) surrounded by lamellar bone matrix within which osteocytes reside. Named after Clopton Havers (1650-1702) an English physician and anatomist. PMID 12999959
  • Howship's lacuna - (resorptive bay) the historic name for the shallow bay or cavity lying directly under an osteoclast. This is the site of bone matrix resorption. Named after John Howship (1781–1841) a British anatomist who identified this region in 1820.
  • lacuna - (Latin, lacuna = “ditch, gap” diminutive form of lacus = “lake”) lacunae is the plural, cavity in bone or cartilage for cell.
  • lamellar bone - the highly organized strong bone matrix deposited in concentric sheets with a low proportion of osteocytes. Many collagen fibers parallel to each other in the same layer. Replaces woven bone.
  • medullary cavity - (bone marrow) refers to the cavity within the bone, that is lined with cells (endosteum) and filled with bone marrow. in the adult, this can also be identified as either red or yellow marrow.
  • mesenchymal progenitor cells - (MPCs) cells able to differentiate in various types of connective tissue, including cartilage, bone and adipose tissue.
  • metaphysis - anatomical term that connecting region, that lies between the diaphysis and epiphysial line.
  • osteoblast - The mesenchymal cells that differentiate to form the cellular component of bone and produce bone matrix. Mature osteoblasts are called osteocytes. (More? Musculoskeletal Development - Bone)
  • osteoclast - Cells that remove bone (bone resorption) by enzymatically eroding the bone matrix. These cells are monocyte-macrophage in origin and fuse to form a multinucleated osteoclast. These cells allow continuous bone remodelling and are also involved in calcium and phosphate metabolism. The erosion cavity that the cells lie iwithin and form is called Howship's lacuna. (More? Musculoskeletal Development - Bone)
  • osteocyte - The mature bone-forming cell, which form the cellular component of bone and produce bone matrix. Differentiate from osteoblasts, mesenchymal cells that differentiate to form bone. (More? Musculoskeletal Development - Bone)
  • osteon - (Haversian system) the functional unit of compact bone. Consists of a central canal (Haversian canal) surrounded by lamellar bone matrix within which osteocytes reside.
  • pedicle - (Latin, pediculus = small foot) part of the vertebral arch forming the segment between the transverse process and the vertebral body.
  • periosteum - the cellular region and fibrous layer lying on the outside of the bone.
  • primary centre of ossification - the first area where bone growth occurs between the periosteum and cartilage.
  • resorptive bay - (Howship's lacuna) the shallow bay or cavity lying directly under an osteoclast. This is the site of bone matrix resorption.
  • sclerotome - ventromedial half of each somite that forms the vertebral body and intervertebral disc.
  • suture - in the skull a form of articulation where the contiguous margins of the bones are united by a thin layer of fibrous tissue.
  • woven bone - the first deposited weaker bone matrix with many osteocytes and a matrix disorganized structure. Replaced by lamellar bone. Seen in developing, healing and bone disease.
Other Terms Lists  
Terms Lists: ART | Birth | Bone | Cardiovascular | Cell Division | Gastrointestinal | Genetic | Hearing | Heart | Immune | Integumentary | Neural | Oocyte | Palate | Placenta | Renal | Respiratory | Spermatozoa | Ultrasound | Vision | Historic | Glossary
  • annulus fibrosus - the circularly arranged fibers (derived from sclerotome)that together with the nucleus pulposus (derived from notochord) form the intervertebral disc (IVD) of the vertebral column.
  • axial mesoderm - (=notochord)
  • cartilage - connective tissue from mesoderm in the embryo forms the initial skeleton which is replaced by bone. In adult, found on the surface of bone joints.
  • Cbfa1 - Core-Binding Factor 1 (Runx2) transcription factor protein key to the differentiation of bone OMIM: Cbfa1
  • centrum - the primordium of the vertebral body formed initially by the sclerotome.
  • clavicle - (Latin, clavicle = little key) bone which locks shoulder to body.
  • dermatome -
  • dermomyotome - dorsolateral half of each somite that forms the dermis and muscle.
  • ectoderm - the layer (of the 3 germ cell layers) which form the nervous system from the neural tube and neural crest and also generates the epithelia covering the embryo.
  • endochondrial ossification - the process of replacement of the cartilagenous framework by osteoblasts with bone.
  • epaxial myotome - the dorsal portion of the myotome that generates dorsal skeletal muscles (epaxial muscles), which include other muscles associated with the vertebrae, ribs, and base of the skull.
  • extracellular matrix - material secreted by and surrounding cells. Consists if fibers and ground substance.
  • fibroblast growth factors - (FGF) a family of at least 10 secreted proteins that bind membrane tyrosine kinase receptors. A patterning switch with many different roles in different tissues. (FGF8 = androgen-induced growth factor (AIGF)
  • fibroblast growth factor receptor - receptors comprise a family of at least 4 related but individually distinct tyrosine kinase receptors (FGFR1- 4). They have a similar protein structure, with 3 immunoglobulin-like domains in the extracellular region, a single membrane spanning segment, and a cytoplasmic tyrosine kinase domain.
  • growth factor - usually a protein or peptide that will bind a cell membrane receptor and then activates an intracellular signaling pathway. The function of the pathway will be to alter the cell directly or indirectly by changing gene expression. (eg shh)
  • hox - (=homeobox) family of transcription factors that bind DNA and activate gene expression. Expression of different Hox genes along neural tube defines rostral-caudal axis and segmental levels.
  • hypaxial myotome - the ventral portion of the myotome that generates ventral skeletal muscles (hypaxial muscles) which include some vertebral muscles, the diaphragm, the abdominal muscles, and all limb muscles.
  • intercostal- the region between adjacent ribs, usually comprising intercostal muscles and connective tissue.
  • intervertebral disc- (IVD) the annulus fibrosus+nucleus pulposus together form the intervertebral disc (IVD) of the vertebral column. This is the flexible region between each bony vertebra that allows the column to be bent.
  • lumbar plexus - mixed spinal nerves innervating the lower limb form a complex meshwork (crossing).
  • mesenchymal progenitor cells - (MPCs) cells able to differentiate in various types of connective tissue, including cartilage, bone and adipose tissue.
  • mesoderm - the middle layer of the 3 germ cell layers of the embryo. Mesoderm outside the embryo and covering the amnion, yolk and chorion sacs is extraembryonic mesoderm.
  • myoblast - the undifferentiated mononucleated muscle cells that will fuse together to form a multinucleated myotube, then mature into a muscle fibre.
  • MyoD - transcription factor involved in the determination of muscle cells in the somite. A basic helix-loop-helix factor which binds DNA.
  • myotome - the portion of the dermamyotome that generates skeletal muscle. Has 2 components epaxial (dorsal muscles ) hypaxial (ventral muscles).
  • neural crest - cell region at edge of neural plate, then atop the neural folds, that remains outside and initially dorsal to the neural tube when it forms. These paired dorsal lateral streaks of cells migrate throughout the embryo and can differentiate into many different cell types(=pluripotential). Those that remain on the dorsal neural tube form the sensory spinal ganglia (DRG). Neural crest cells migrate into the somites.
  • osteoblast - The mesenchymal cells that differentiate to form the cellular component of bone and produce bone matrix. Mature osteoblasts are called osteocytes. (More? Musculoskeletal Development - Bone)
  • osteoclast - Cells that remove bone (bone resorption) by enzymatically eroding the bone matrix. These cells are monocyte-macrophage in origin and fuse to form a multinucleated osteoclast. These cells allow continuous bone remodelling and are also involved in calcium and phosphate metabolism. The erosion cavity that the cells lie iwithin and form is called Howship's lacuna. (More? Musculoskeletal Development - Bone)
  • osteocyte - The mature bone-forming cell, which form the cellular component of bone and produce bone matrix. Differentiate from osteoblasts, mesenchymal cells that differentiate to form bone. (More? Musculoskeletal Development - Bone)
  • osteon - The anatomical (histological) unit structure (principal structure) of compact bone. (More? Musculoskeletal Development - Bone)
  • Pax - name derived from Drosophila gene 'paired' (prd) the 'paired box' is a amino end 124 amino-acid conserved domain (signature aa 35-51: P-C-x(11)-C-V-S). Transcription factor of the helix-turn-helix structural family, DNA binding, and activating gene expression. In human, nine member proteins from Pax-1 to Pax-9. Regulate differentiation of many different tissues. Some members of the family (PAX3, PAX4, PAX6, PAX7) also contain a functional homeobox domain.
  • pedicle - (Latin, pediculus = small foot) part of the vertebral arch forming the segment between the transverse process and the vertebral body.
  • primary centre of ossification - the first area where bone growth occurs between the periosteum and cartilage.
  • sclerotome - ventromedial half of each somite that forms the vertebral body and intervertebral disc.
  • segmentation - to break a solid structure into a number of usually equal size pieces.
  • somatic mesoderm - derived from lateral mesoderm closest to the ectoderm and separated from other component of lateral mesoderm (splanchnic, near endoderm) by the intraembryonic coelom.
  • somite - segmental block (ball) of mesoderm formed from paraxial mesoderm adjacent to notochord (axial mesoderm). Differentiates to form initially sclerotome and dermamyotome (then dermotome and myotome).
  • somitic mesoderm-
  • somitocoel - a transient cavity that appears within each of the the early forming somites then is lost.
  • somitogenesis - the process of segmentation of the paraxial mesoderm to form "mesoderm balls" beginning cranially (humans day20) and extending caudally at 1 somite/90 minutes until approx. 44 pairs have been formed.
  • sonic hedgehog - (=shh) secreted growth factor that binds patched (ptc) receptor on cell membrane. SHH function is different for different tissues in the embryo. In the nervous system, it is secreted by the notochord, ventralizes the neural tube, inducing the floor plate and motor neurons. In the Limb it is secreted by the zone of polarizing activity (ZPA) organizing limb axis formation.
  • Tbx - T-box genes (transcription factor) involved in mouse forelimb (Tbx4) and hindlimb (Tbx5) specification.
  • transcription factor- a factor (protein or protein with steroid) that binds to DNA to alter gene expression, usually to activate. (eg steroid hormone+receptor, Retinoic acid+Receptor, Hox, Pax, Lim, Nkx-2.2).
  • vertebral body- formed by centrum, vertebral arch, facets for ribs. It is the mature vertebral structure formed by the 5 secondary ossification centers after puberty.
  • vertebral column - name given to the complete structure formed from the alternating segments of vertebra and intervertebral discs which support the spinal cord.
  • vertebral foramen - the dorsal cavity within each vertebra, generated by the vertebral arch that surrounds the spinal cord.
  • Wnt7a - The designation 'Wnt' was derived from 'wingless' and 'int'. The Wnt gene was first defined as a protooncogene, int1. Humans have at least 4 Wnt genes: Wnt7a gene is at 3p25 encoding a 349aa secreted glycoprotein. A patterning switch with different roles in different tissues. The mechanism of Wnt distribution (free diffusion, restricted diffusion and active transport) and all its possible cell receptors are still being determined. At least one WNT receptor is Frizzled (FZD). The Frizzled gene family encodes a seven-transmembrane receptor.

2015

ECHO360 Recording  
ECHO360 icon.gif

Links only work with currently enrolled UNSW students.

Lecture 17 -

The Powerpoint file used to present this lecture is available as a pdf document 2013 Musculoskeletal Lecture Lecture Date: 2013-09-17 Lecture Time: 12:00 Venue: Wallace Wurth LG02 Speaker: Steve Palmer.

Musculoskeletal medical conditions

Health expenditure for arthritis and musculoskeletal conditions, 2004-05

"Arthritis and musculoskeletal conditions affect more than 6 million Australians. In 2004-05, direct health expenditure on these conditions amounted to $4.0 billion or 7.5% of total allocated health expenditure in Australia."


  • Williams-Beuren syndrome is a genetic disease caused by a hemizygous deletion of 28 genes on chromosome 7. Leads to a distinctive set of craniofacial features. Probably caused by defects in patterning rather than differentiation as all of the structures form normally, just in slightly different positions relative to each other.

Neuromuscular and regenerative medicine unit, SOMS Craniofacial abnormalities in Williams-Beuren syndrome


Textbooks

The Developing Human: Clinically Oriented Embryology

The Developing Human, 9th edn.jpg Citation: The Developing Human: clinically oriented embryology 9th ed. Keith L. Moore, T.V.N. Persaud, Mark G. Torchia. Philadelphia, PA: Saunders, 2011.

Larsen's Human Embryology

Larsen's human embryology 4th edn.jpg Citation: Larsen's human embryology 4th ed. Schoenwolf, Gary C; Larsen, William J, (William James). Philadelphia, PA : Elsevier/Churchill Livingstone, c2009.
Logo.png Hill, M.A. (2012) UNSW Embryology (12th ed.). Sydney:UNSW.
Head Links: Introduction | Medicine Lecture | Medicine Lab | Science Lecture | Lecture Movie | Science Lab | Craniofacial Seminar | Mouth | Palate | Tongue | Placodes | Skull Development | Head and Face Movies | Abnormalities | Category:Head
Historic Head Embryology  
1910 Skull | 1910 Skull Images | 1912 Nasolacrimal Duct | 1921 Human Brain Vascular | 1923 Head Subcutaneous Plexus | 1919 21mm Embryo Skull | 1920 Human Embryo Head Size | 1921 43 mm Fetal Skull | Historic Disclaimer


Old Textbook Links

The Developing Human, 8th edn.jpg Moore, K.L. & Persuad, T.V.N. (2008). The Developing Human: clinically oriented embryology (8th ed.). Philadelphia: Saunders.
(chapter links only work with a UNSW connection).
Larsen's human embryology 4th edn.jpg Schoenwolf, G.C., Bleyl, S.B., Brauer, P.R. and Francis-West, P.H. (2009). Larsen’s Human Embryology (4th ed.). New York; Edinburgh: Churchill Livingstone.
(chapter links only work with a UNSW connection).
Logo.png Hill, M.A. (2011) UNSW Embryology (11th ed.). Sydney:UNSW.
Musculoskeletal Links: Introduction | Mesoderm | Somitogenesis | Limb | Cartilage | Bone | Bone Timeline | Axial Skeleton | Skull | Joint | Muscle | Muscle Timeline | Tendon | Diaphragm | Lecture - Musculoskeletal Development | Lecture Movie | Abnormalities | Limb Abnormalities | Cartilage Histology | Bone Histology | Skeletal Muscle Histology | Category:Musculoskeletal
Historic Musculoskeletal Embryology  
1902 - Pubo-femoral Region | Spinal Column and Back | Body Segmentation | Cranium | Body Wall, Ribs, and Sternum | Limbs | 1901 - Limbs | 1902 - Arm Development | 1906 Human Embryo Ossification | 1906 Lower limb Nerves and Muscle | 1907 - Muscular System | Skeleton and Limbs | 1908 Vertebra | 1909 Mandible | 1910 - Skeleton and Connective Tissues | Muscular System | Coelom and Diaphragm | 1913 Clavicle | 1920 Clavicle | 1921 - External body form | Connective tissues and skeletal | Muscular | Diaphragm | 1929 Rat Somite | 1932 Pelvis | 1940 Synovial Joints | 1943 Human Embryonic, Fetal and Circumnatal Skeleton | 1947 Joints | 1949 Cartilage and Bone | 1957 Chondrification Hands and Feet | 1968 Knee
Links: Embryology Textbooks