Fetal Circulation Flashcards
Primitive heart tube receives blood from what 3 venous sources?
- Vitelline veins
- umbilical vesicle/yolk sac to heart - Cardinal veins
- body to heart - Umbilical veins
- chorionic sac/placenta to heart
During 4th week of development, where does oxygenated blood exit the heart?
via aortic sacs and the pharyngeal (aortic) arch arteries that supply the pharyngeal arches and flows to the dorsal aorta
what does the dorsal aorta become?
-fuse caudally to become the common aorta which delivers blood to the rest of the body
When do pharyngeal arch arteries develop?
4th week
What do pharyngeal arch artery derivatives form?
form the fetal arterial system by 8th week
How many pairs of pharyngeal arch arteries form?
- 6 pairs develop
- by the time the 6th pair forms, the first 2 have disappeared
1st PAA derivative?
- mostly disappears
- contribution to Maxillary Artery
2nd PAA derivative?
- disappears mostly
- contribution to Hyoid and Stapedial arteries
3rd PAA?
- ventral part to Common Carotid
- dorsal part to Internal Carotid
4th PAA?
- right side: proximal part of Subclavian artery
- left side: part of Aortic arch
5th PAA?
rudimentary vessel
6th PAA?
- right side: part of right pulmonary artery
- left side: part of left pulmonary artery and ductus arteriosus
Change of course of Recurrent Laryngeal Nerve?
- Asymmetric transformation of 6th PAA cause recurrent laryngeal to change
- Right degenerates distally, moves to hook around proximal right Subclavian artery
- Left hooks around ductus arteriosus which involutes to become ligamentum arteriosum after birth
Coronary vessel formation?
- Proepicardium provides cell precursors for coronary vessels
- Proepicardial cells migrate out to form epicardium
- Epicardium undergoes EMT to form vascular smooth muscle cells and endothelial cells of coronary vessels
- Newly formed coronary arteries enter the Aorta
Vitelline Veins development?
- drain yolk sac and enter sinus venous
- anastomose around duodenum to form portal vein
- hepatic sinusoids incorporate into liver
- Left vitelline regresses
- Right vitelline form hepatic portal system (superior mesenteric) and part of IVC