CV Development-02

Question 1

fetal circulatory system

Answer 1

many modifications to CV circuit because the lungs are not yet developed nor many other organs for waste extraction

Question 2

what are the 3 shunts in the fetal circulation?

Answer 2

ductus arteriosus, ductus venosus, foramen ovale

Question 3

what type of circuit is the fetal circulation?

Answer 3

2 open circuits operating in parallel

Question 4

what type of circuit is the adult circulation?

Answer 4

2 closed circuits arranged in series

Question 5

where is pressure greater in fetal circulation?

Answer 5

right side

Question 6

where is pressure greater in adult/postnatal circulation?

Answer 6

left side

Question 7

postnatal circulatory system

Answer 7

pulmonary circuit on right side returning deoxygenated blood to lungs and systemic circuit delivering oxygenated blood to the tissues

Question 8

what is the purpose of shunts in fetal circulation?

Answer 8

so that oxygenated blood from the placenta can quickly reach/bypass to the fetus’ systemic circuit quickly to feed tissues

Question 9

umbilical vein

Answer 9

delivers oxygenated blood from the placenta to the fetus

Question 10

ductus venosus

Answer 10

connects the umbilical vein to the IVC, bypassing the liver

Question 11

ductus arteriosus

Answer 11

diverts blood from the pulmonary trunk to the aorta

Question 12

foramen ovale

Answer 12

connects the two atria in the fetal heart, diverting blood from the RA to the LA

Question 13

left and right umbilical arteries

Answer 13

from systemic circuit; located next to the urinary bladder, go up through umbilicus and wrap around umbilical vein to send deoxygenated blood away from fetus

Question 14

what does the foramen ovale become?

Answer 14

fossa ovalis

Question 15

what does the ductus arteriosus become?

Answer 15

ligamentum arteriosum

Question 16

what does the ductus venosus become?

Answer 16

ligamentum venosum

Question 17

what do the umbilical arteries become?

Answer 17

medial umbilical ligaments

Question 18

what does the umbilical vein become after closure?

Answer 18

ligamentum teres

Question 19

tubular heart development

Answer 19

1. two tubular hearts fuse together 2. bulges/sacculations 3. saccular tube elongates (heart prominence) 4. valves form 5. two sides of tube come together and start eating away walls to create chambers and set up valves

Question 20

what important structure does the truncus arteriosus become?

Answer 20

pulmonary trunk and aorta

Question 21

what important structure does the bulbus cordis become?

Answer 21

right ventricle

Question 22

what important structure does the ventricle become?

Answer 22

the left ventricle

Question 23

what important structure does the atrium become?

Answer 23

mostly the LA and parts of the RA, right and left auricles

Question 24

what important structure does the sinus venosus become?

Answer 24

much of the RA, SA node, coronary sinus

Question 25

division of the truncus arteriosus

Answer 25

lateral ridges of the TA form the aorticopulmonary septum and it will spiral 180º when completely formed

Question 26

where do the SL valves form?

Answer 26

at the base of the truncus arteriosus

Question 27

persistent truncus

Answer 27

aorticopulmonary septum fails to form, mixed blood from L and R ventricles creating issues w/ ability to oxygenate blood and deliver this blood to the body (similar to 3 chambered hearts)

Question 28

transposition of the great vessels

Answer 28

aorticopulmonary septum forms, but fails to spiral 180º; this condition is fatal unless the following are also present: PDA, ASD, VSD

Question 29

valve stenosis

Answer 29

due to unequal partitioning, a result of deviation of the aorticopulmonary septum (one sided expanded, one side stenosed)

Question 30

patent ductus arteriosus (PDA)

Answer 30

ductus arteriosus remains open, can lead to volume overload in the pulmonary circuit, increased pulmonary blood flow may cause pulmonary edema – treated by surgically stitching

Question 31

atrial septal defect (ASD)

Answer 31

foramen oval fail to close

Question 32

formation of interatrial septum

Answer 32

2 phases: wall forms first, second wall forms behind it to form opening and flap;
septum primum (1st wall), foramen primum (1st hole), foramen secondum (2nd hole), septum secundum (2nd wall)

Question 33

septum primum (1st wall)

Answer 33

begins at top of left and right atrium and grows toward center of heart

Question 34

foramen primum (1st hole)

Answer 34

keeps developing down heart, once it starts reaching the center of the heart, upper portion of wall starts developing holes - foramen secundum (2nd hole)

Question 35

septum secundum (2nd wall)

Answer 35

forms in behind 1st wall, does not form completely and also has hole; 1st wall forms flap over 2nd wall’s hole (foramen ovale) called valve of foramen ovale

Question 36

what are 2 major vascular changes after birth?

Answer 36

1. increased systemic resistance w/ loss of placenta

2. decreased pulm. vascular resistance w breathing

Question 37

formation of interventricular septum

Answer 37

1. wall begins forming at apex 2. grows toward fibrous skeleton; first part is true IV septum, final segment is membranous portion

Question 38

formation of AV valves

Answer 38

form from stem cells found within bulges called cushions/swellings found around fibrous skeleton, 3 cushions for tricuspid valve and 2 for bicuspid

Question 39

tetralogy of Fallot

Answer 39

pulmonary valve stenosis, overriding aorta, VSD, RV hypertrophy