Embryology Flashcards
Which structure develops into the kidney and renal duct?
The metanephros
At what age foes the anterior fontanelle close
At what age foes the posterior fontanelle close
Anterior - 18 months
Posterior - 2 months
In foetal circulation, umbilical venous blood passes through which structure before entering the inferior vena cava?
Ductus venosus
A bicornuate uterus is the result of failure of which embryonic structure to correctly fuse?
Paramesonephric duct
How many cells are there on Day 3?
Day 3 - Morula - 12 to 16 cells
Day 4/5 - Blastocyst
Day 6 - Implantation
At what age are there the maximum number of ova?
20 weeks gestation
What drug is used to close a symptomatic ductus arteriosus?
Indomethacin
(a prostaglandin antagonist)
The renal tubules develop from
Metanephros
Uterus didelphus results from the failure of fusion of which structure
Paramesonephric duct
On fetal US abdomen shows defect in abdominal wall with intestine protruding out covered with layer
Omphalocele
O - omphalocele
In a bubble ‘O’
What is the embryonic origin of the trigone of urinary bladder?
Mesoderm
(caudal end of the mesonephric duct)
The rest of the bladder is from the endoderm
What does the genital ridge give rise to in the female foetus?
Ovary
What is the name of a placenta where the umbilical cord is attached to the margin?
Battledore placenta
The round ligament of the uterus develop From which embryonic structure?
Gubernaculum
What is the embryological origin of Gartners duct cyst?
Mesonephric duct
Ductus venosus is completely obliterated after birth to form what adult structure?
Ligamentum venosum
Ductus venosus –> ligamentum venosum
Which cells produce mullerian-inhibiting substance in fetal testis?
Sertoli cells
Where in the developing embryo do primordial germ cells originate?
Yolk Sac Endothelium
The greater omentum is derived from which of the following embryonic structures? Be specific
Dorsal mesogastrium
In Horseshoe Kidney what structure prevents the kidney from ascending from pelvis to abdomen?
Inferior mesenteric artery
(the arterial supply of the hind gut)
Primary mechanism of shunting blood away from the pulmonary circulation
Ductus arteriosus
Gonads are derived from which part of which embryonic layer?
Intermediate mesoderm
The ureteric bud is derived from which of the following structures ?
Mesonephric duct
Mesonephros –> ureteric bud –>
Ureter, renal pelvis, calyx, collecting duct
Metanephros–>
Glomerulus, capsule, PCT/Henle/DCT
Allantois embryonic origin
Endoderm
CNS is the most affected during teratogenesis. What is the first sensation developed in the fetus?
Touch
Gastrulation is process of
Development of three germ layers
In fetal circulation which structure caryy oxygenated blood from right atrium to left atrium?
Foramen ovale
Central lump pointed to by arrow
Inner cell mass
When does adult haemoglobin start being produced?
At birth
Embryonic origin of oocytes
Primordial germ cell
Embryological origin of appendix testis
Paramesonephric duct
What do the umbilical arteries become?
What does the umbilical vein become?
Umbilical arteries - medial umbilical ligaments
Umbilical vein - ligamentum teres
Embryological origin of the lower 2/3 of the vagina
Endoderm and urogenital sinus
Remember endoderm also makes the cloaca
Embryological origin of the bladder
Endoderm:
Cloaca –>urogenital sinus –> bladder
When do the primordial germ cells migrate from the yolk sac to the mesoderm?
/Where are germ cells at week 4
Week 5
Yolk sac
What is the main Hb in fetus 32 weeks?
HbF
What structures form from the 2nd pharyngeal arch?
Muscles - muscles of facial expression
Nerve - Facial nerve
Skeletal - stapes, temporal styloid process, hyoid, stylohyoid
What two structures does the ductus venosus join?
umbilical vein
IVC
The ductus arteriosus connects which two structures?
Aorta and pulmonary artery
Which structure establishes bilateral symmetry, determines the site of gastrulation, and initiates germ layer formation?
Primitive streak
What day does the neural tube close?
30 (4 weeks)
What structures does the vitilline duct connect?
Yolk sac and midgut
What is the source of cholesterol in a term foetus?
Foetal liver
At what week does the foetus begin to produce urine?
At what week does foetal urine become the major contributor to amniotic fluid?
Week 10
Week 18
At what cell stage do monochorionic diamniotic twins split?
4 - 8 days - early blastocyst
Morula day 3
Blastocyst day 4-5
Implantation day 6
When does the anterior pituitary begin to develop?
6-7 weeks (?)
What structure does ligamentum arteriosus come from?
Ductus arteriosus
