Loading....
Coupon Accepted Successfully!

Paediatric

Open Flashcards

CVS

Question
17 out of 63
 

Orygenated blood to the fetus is carried by- (LQ)



A Umblical artery
B Umblical vein

C SVC
D Pulmonary artery

Ans. B

Umblical vein

Fetal circulation

a. Fetal circulation differs from adult circulation in several ways. Almost all differences are attributable to the fundamental difference in the site of gas exchange.

b. In the adult gas exchange occurs in the lungs, while in the fetus placenta provides the exchange of gases an nutrients.

Course of fetal circulation

a. Blood returning to heart

i. Blood orytgenated in the placenta returns by way of the umblical vein, which enter the fetus at the umbilicus and course through to join the portal vein.

ii. The ductus venous is a bypass shunt between portal vein and IVC.

iii. Most of the umblical venous blood shu:rts through the ductus venosus to the IVC.

iv. Blood from IVC (which carries the blood drained ftom lower extrernities, umblical veins, hepatic veins and renal veins enters the right otrium.

v. On reaching the right atrium, about 1/3rd of total inferior vena caval return of blood enters the left atrium through formen oval

vi. The rest two third mixes with the venous return from SVC (which carries the blood drained from head, neck and upper limbs) to enter the right ventricles.

b. Blood coming out of the heart

i. Right side

• The right ventricle pumps out the blood into pulrnonary trunk -+ very small amount of this blood enters the pulrnonary circulation because ttre lungs are collapsed and pulmonary vascular resistance is high.

• Most ofthis blood passes to descending aorta through ductus arteriosus, a shunt between plumonary trunk and desending Aorta.

• Descending aorta carries blood to umblicus through umblical artery for oxygenation.

• Descending aorta also supplies the blood to lower lumbs, kidney and abdominal viscera.

ii. Left side

• The left ventricle pumps blood into the ascending aorta for distribution in coronary circulation, head and upper limbs.

CVS Flashcard List

63 flashcards
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
15)
16)
17)
18)
19)
20)
21)
22)
23)
24)
25)
26)
27)
28)
29)
30)
31)
32)
33)
34)
35)
36)
37)
38)
39)
40)
41)
42)
43)
44)
45)
46)
47)
48)
49)
50)
51)
52)
53)
54)
55)
56)
57)
58)
59)
60)
61)
62)
63)