fetal circulation

Question 1

fetal circulation is designed to

Answer 1

serve prenatal needs and prepare for postnatal modifications

Question 2

fetal heart pressure

Answer 2

P right > P left

Question 3

ductus venosus purpose

Answer 3

to bypass fetal liver

Question 4

ductus arteriosus purpose

Answer 4

to bypass lungs

Question 5

foramen ovale purpose

Answer 5

to bypass right side of fetal heart and lungs

Question 6

highly oxygenated blood in the fetus is directed

Answer 6

to the developing brain

Question 7

first step of fetal circulation

Answer 7

highly oxygenated blood from the placenta enters via a single umbilical vein

Question 8

second step of fetal circulation

Answer 8

half blood in umbilical vein bypasses liver via the ductus venosus to enter the IVC, the other half enters the hepatic sinusoids to supply developing liver tissue

Question 9

third step of fetal circulation

Answer 9

IVC enters RA of heart, most of this blood then passes through foramen ovale into the LA

Question 10

fourth step of fetal circulation

Answer 10

highly oxygenated blood mixes with small amounts of deoxygenated blood from pulmonary veins in the LA

Question 11

fifth step of fetal circulation

Answer 11

fairly oxygenated blood travels from LA into LV and then to ascending aorta, arch of aorta and main branches

Question 12

sixth step of fetal circulation

Answer 12

deoxygenated blood returns via SVC and into RA where blood is still highly oxygenated

Question 13

seventh step of fetal circulation

Answer 13

blood that didn’t pass through the foramen ovale mixes with deoxygenated blood in the RA, then enters the RV and leaves via the pulmonary trunk

Question 14

which ventricle has thicker walls in the fetus

Answer 14

right

Question 15

eighth step of fetal circulation

Answer 15

10% of moderately oxygenated blood in pulmonary trunk enters pulmonary arteries to supply developing lungs, then this blood returns to LA

Question 16

ninth step of fetal circulation

Answer 16

90% of moderately oxygenated blood in pulmonary trunk passes through ductus arteriosus and travels down descending aorta

Question 17

ductus arteriosus protects

Answer 17

the lungs from overloading

Question 18

what keeps the ductus arteriosus patent

Answer 18

prostaglandins

Question 19

tenth step of fetal circulation

Answer 19

35% of blood in descending aorta supplies fetal viscera, 65% passes into umbilical arteries and returns to placenta

Question 20

timing of modifications

Answer 20

begin during labor and delivery, should be mostly done one week postnatal

Question 21

neonatal heart pressure

Answer 21

P right < P left

Question 22

umbilical arteries become

Answer 22

bilateral internal iliac and superior vesical arteries

Question 23

umbilical veins become

Answer 23

round ligament of liver

Question 24

ductus venosus becomes

Answer 24

ligamentum venosum

Question 25

foramen ovale becomes

Answer 25

fossa ovalis

Question 26

ductus arteriosus becomes

Answer 26

ligamentum arteriosum

Question 27

peripheral cyanosis

Answer 27

manifests in extremities, nail beds, periorbital areas

Question 28

central cyanosis

Answer 28

manifests all over body, even in mucous membranes of lips and tongue

Question 29

patent foramen ovale

Answer 29

type of atrial septal defect, deficient closure of foramen ovale

Question 30

ventral septal defects

Answer 30

incorrect interventricular septum formation L to R shunting

Question 31

atrial septal defects

Answer 31

incorrect interatrial septum formation L to R shunting

Question 32

patent ductus arteriosus

Answer 32

persistant ductus arteriosus L to R shunting

Question 33

coarctation of the aorta

Answer 33

narrow descending aorta near ductus arteriosus increased BP in UE

Question 34

transposition of the great vessels

Answer 34

two closed systems with improper ventricular-great vessel connections no shunting, cyanotic known as blue babies

Question 35

what causes transposition of the great vessels

Answer 35

aorticopulmonary septum fails to spiral due to incorrect neural crest cell migration

Question 36

tetralogy of Fallot

Answer 36

right heart obstructive lesion shunting and cyanotic, "blue kids" pressure R > L

Question 37

four features of tetralogy of Fallot

Answer 37

"prove" pulmonary stenosis right ventricular hypertrophy over-riding aorta ventricular septal defect

Question 38

hypoplastic left heart syndrome

Answer 38

left heart obstructive lesion, lack of development of left side of heart pressure R > L, cyanotic

Question 39

etiology of tetralogy of fallot

Answer 39

incorrect neural crest cell migration leads to unequal division of truncus arteriosus

Question 40

persistent truncus arteriosus

Answer 40

single outflow tract and VSD, cyanotic