Respiratory, GIT, cardiac Flashcards
Which germ layers form the respiratory system?
Endoderm- lining of lungs
Splanchnic Mesoderm (LPM)- vessels, smooth muscle, cartilage
Name the different stages of lung development with timings
- Budding (week 4)
- Pseudoglandular stage (week 8-16)
- Canalicular stage (week 16-26)
- Terminal sac stage (week 26+)
Failure of what structure to form causes TOF?
Tracheo-oesophageal septum
Describe the boundaries of the gut regions
Foregut: up to 1st part duodenum
Midgut: 2nd duodenum to 2/3 transverse colon
Hindgut: distal 1/3 transverse to rectum
Describe the arterial supply of the foregut
Coeliac A ->
Left gastric
Splenic
Common hepatic
Describe the arterial supply of the midgut
SMA ->
Jejunal
Ileal
Ileocolic
Right colic
Middle colic
Describe the arterial supply of the hindgut
IMA ->
Left colic
Sigmoid
Superior rectal
What does the liver and pancreas derive from?
Foregut of the endoderm
By which week is does the fetus produce surfactant?
Begins at week 24-28
Production sufficient to breathe by 34/35 weeks
Describe the difference between exomphalos and gastroschisis
Exomphalos: gut fails to return to cavity, sac outside body, cord inserts into sac. Assoc w aneuploidy
Gastroschisis: gut protrudes thru wall lateral to cord insertion. No risk aneuploidy
What does the diaphragm arise from?
Septum transversum + pleuroperitoneal membrane mostly
What does the notochord give rise to?
Nucleus polposus
What does the anterior pituitary derive from?
Ectoderm -> Rathke’s pouch -> Ant pituitary
What is the origin of the median and medial umbilical ligaments?
Median: urachus (
Medial: umbilical artery
What is the urachus?
Fibrous remnant of the allantois, which is a canal connecting the urinary bladder and umbilicus
