embryology Flashcards
blastocyst deveopment
bilayer of cells (epiblast and hypoblast)- GASTRULATION then occurs, which forms a trilayer (ectoderm, mesoderm and endoderm)
what ectoderm, mesoderm and endoderm form
skin and CNS, muscles and blood and skeleton and heart, lungs and liver
what is neurulation
ectoderm forms CNS- neural plate forms early on, which fuse to form neural tubue
pre kidney names
most immature is PRONEPHROS, then MESONEPHROS, then METANEPHROS
what duct gives rise to male, and female genital ducts
mesonephric vs paramesonephric
abnormality of kidney
one kidney may be retained in pelvis, eg if they fuse together to form a horseshoe
why male forms rather than female- key hormones
hCG stimulates testosterone, and AMH forms (produced by SERTOLI), which causes regression of paramesonephric duct
key male gonad disorder
androgen insenstivity syndrome (mutant androgen receptor)- leads to lack of mesonephric duct, but NO female strcuture (as AMH production normal)
key female disorder
congential adrenal hyperplasia- mutation in 21 hydroxylase= less cortisol production from adrenals= more ACTH= more androgens from adrenals, but NO male structures (no testosterone+ AMH)
heart development
cardiogenic develop cells develop into a U shape, which form a pair of heart tubes, which fuse to form a single tube- septation then occurs to form the 4 chambers
difference between foetal and adult heart, and why
foramen ovale (gap between atria) and ductus arteriosus (gap between aorta and PA), as little blood needed to lungs
tetralogy of fallot- cardiac abnormalities in foetus
include pulmonary stenosis and ventricular septal defect
vascular abnormality- transposition of vessels
aorta connected to RIGHT ventricle, PA connected to left- only has effects when foramen ovale/ductus arteriosus close, causing cyanosis (hypoxia)
treatment of transposition
prostaglandins to keep the holes open, or surgery to switch arteries
