fetal circulation and embryology

Question 1

at 21 to 23 days in embryo the heart consist of

Answer 1

the heart tubes are forced to midline during a folding process that fuses them into a single tube

Question 2

the sinus venosus is formed by

Answer 2

the union off 3 veins (common, vitelline, and umbilical)

Question 3

the sinus venosus becomes the…

Answer 3

SVC , IVC, pulmonary veins, coronary sinus and oblique vein of the LV and posterior portions and of the right/left atria

Question 4

the primitive atria divides into

Answer 4

the right and left atria

Question 5

the atrioventricular sulcus divides into

Answer 5

primitive atria and ventricle

Question 6

proximal bulbus cordis gives rise to

Answer 6

trabecular expansion that forms the apex of the RV

Question 7

mid portion of the bulbus cordis forms the

Answer 7

right and left outflow tracts

Question 8

distal bulbus cordis or truncus arteriosus forms the

Answer 8

aorta and MPA

Question 9

1st aortic arch

Answer 9

pair regresses

Question 10

2nd aortic arch

Answer 10

leads to mandibular and maxillary arteries

Question 11

3rd aortic arch

Answer 11

leads to common and internal carotid arteries.

Question 12

4th aortic arch

Answer 12

leads to adult aorta and forms the left subclavian and braciocephalic trunk

Question 13

6th aortic arch

Answer 13

derive the main left and right pulmonary arteries

Question 14

the endocardial cushion develops into

Answer 14

mitral and tricuspid valves

Question 15

when is the fetal heart development complete

Answer 15

at 7 weeks or 49 days

Question 16

when does the heart start to beat

Answer 16

3 weeks or 21 days

Question 17

name the 3 shunts in fetal circulation

Answer 17

foramne ovale
ductus arteriosus
ductus venosus

Question 18

process of fetal circulation

Answer 18

1. placenta
2. umbilical vein
3. small blood into liver
4. blood shunted through ductus venosus
5. IVC
6. RA
7. some blood through RA to RV to MPA
8. most blood shunted through formane ovale
9. blood bypasses the lungs through ductus arterious
10. through aorta

Question 19

the remnant of the ductus arterious becomes the

Answer 19

ligamentum arteriosum

Question 20

the remnant of the ductus venosum becomes

Answer 20

ligament venosum

Question 21

the umbilical veins becomes which ligament

Answer 21

the ligamentum teres