BGDB Sexual Differentiation - Late Embryo: Difference between revisions
From Embryology
mNo edit summary |
mNo edit summary |
||
Line 121: | Line 121: | ||
===Development of the Kidney=== | ===Development of the Kidney=== | ||
{| | |||
| width=420px|<mediaplayer width='400' height='280' image="http://embryology.med.unsw.edu.au/embryology/images/5/59/Renal_001_icon.jpg">File:Nephron_development.mp4</mediaplayer> | |||
| | |||
* The adult kidneys (the metanephroi) form from day 35, from a portion of the intermediate mesoderm called the metanephric blastema (or metanephric mesenchyme). | * The adult kidneys (the metanephroi) form from day 35, from a portion of the intermediate mesoderm called the metanephric blastema (or metanephric mesenchyme). | ||
* They are induced to form by the ureteric buds, outgrowths from the end of the mesonephric ducts, which come into contact with the metanephric blastema. | * They are induced to form by the ureteric buds, outgrowths from the end of the mesonephric ducts, which come into contact with the metanephric blastema. | ||
* Upon contact, they begin to lengthen and bifurcate rapidly in the metanephric blastema – these branches differentiate into the collecting ducts. | * Upon contact, they begin to lengthen and bifurcate rapidly in the metanephric blastema – these branches differentiate into the collecting ducts. | ||
* Both the ureteric buds and the metanephric blastema begin to differentiate; interestingly each induces differentiation in the other structure. | * Both the ureteric buds and the metanephric blastema begin to differentiate; interestingly each induces differentiation in the other structure. | ||
**The ureteric bud is induced by the metanephric blastema to form the collecting tubules, renal pelvis and ureters. | ** The ureteric bud is induced by the metanephric blastema to form the collecting tubules, renal pelvis and ureters. | ||
** The metanephric blastema is induced to form the nephrons. | ** The metanephric blastema is induced to form the nephrons. | ||
|} | |||
{| | {| | ||
| width=320px|<mediaplayer width='295' height='430' image="http://embryology.med.unsw.edu.au/embryology/images/7/71/Renal_blood_01_icon.jpg">File:Renal blood 01.mp4</mediaplayer> | | width=320px|<mediaplayer width='295' height='430' image="http://embryology.med.unsw.edu.au/embryology/images/7/71/Renal_blood_01_icon.jpg">File:Renal blood 01.mp4</mediaplayer> |
Revision as of 11:25, 3 June 2013
Practical 12: Sex Determination | Early Embryo | Late Embryo | Fetal | Postnatal | Abnormalities | 2011 Audio |
Week 8
<mediaplayer width='503' height='480' image="http://embryology.med.unsw.edu.au/embryology/images/2/26/Stage22_URG3d.jpg">File:Stage22_URG3d.mp4</mediaplayer>
Week 8, Carnegie stage 22, male. Page |
Begin by observing the internal structure of the embryo at the end of week 8.
|
Embryo (week 8, Stage 22) Renal
Urinary System Development
Development of the Urinary Bladder
<mediaplayer width='360' height='500' image="http://embryology.med.unsw.edu.au/embryology/images/f/fe/Urogenital_sinus_001_icon.jpg">File:Urogenital_sinus_001.mp4</mediaplayer> | <mediaplayer width='420' height='415' image="http://embryology.med.unsw.edu.au/embryology/images/8/88/Urogenital_septum_001_icon.jpg">File:Urogenital_septum_001.mp4</mediaplayer> | Division of the Cloaca
|
Development of the Urethra
Further development of the urinary system outflow tract, the urethra, varies depending on the sex of the embryo.
- Males - the pelvic urethra forms the membranous urethra, the prostatic urethra and penile urethra. (The sex of the above animation and sections is male)
- Females - the pelvic urethra forms the membranous urethra and the vestibule of the vagina.
Development of the Kidney
<mediaplayer width='400' height='280' image="http://embryology.med.unsw.edu.au/embryology/images/5/59/Renal_001_icon.jpg">File:Nephron_development.mp4</mediaplayer> |
|
<mediaplayer width='295' height='430' image="http://embryology.med.unsw.edu.au/embryology/images/7/71/Renal_blood_01_icon.jpg">File:Renal blood 01.mp4</mediaplayer> |
|
Genital System Development
Male
peritoneal cavity | rete tesits | G3 testis |
- week 8 - males Sertoli cells secrete anti müllerian hormone (AMH), which causes regression of the paramesonephric ducts between the 8th and 10th weeks.
- week 9 to 10 - gonadal cells begin to produce testosterone, which maintains the mesonephric ducts.
- mesonephric ducts go on to form the internal genital tract:
- rete testis
- ductuli efferentes
- vas deferens
Female
- during the same time course as above, the opposite occurs.
- The sex cords degenerate and the genital ridge forms secondary cortical sex cords.
- These induce the primordial germ cells to form the ovarian follicles.
- Due to the lack of AMH and testosterone, the mesonephric ducts degenerate
- paramesonephric ducts go on to form the internal genital tract:
- uterine (fallopian) tubes
- uterus body
- vagina
In both sexes, the external genitalia appear similar until week 12 (GA week 14).
Trigone
<mediaplayer width='445' height='365' image="http://embryology.med.unsw.edu.au/embryology/images/5/5b/Trigone_001_icon.jpg">File:Trigone_001.mp4</mediaplayer> | This animation shows the posterior of the developing bladder between Week 4 and 6.
|
G5 urogenital | urogenital |
Practical 12: Sex Determination | Early Embryo | Late Embryo | Fetal | Postnatal | Abnormalities | 2011 Audio |
Additional Information
References
BGDB: Lecture - Gastrointestinal System | Practical - Gastrointestinal System | Lecture - Face and Ear | Practical - Face and Ear | Lecture - Endocrine | Lecture - Sexual Differentiation | Practical - Sexual Differentiation | Tutorial
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, April 26) Embryology BGDB Sexual Differentiation - Late Embryo. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/BGDB_Sexual_Differentiation_-_Late_Embryo
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G