Development of the Heart Lecture Points

Question 1

the heart starts as a …

Answer 1

blood vessel

Question 2

where do embryonic blood vessels form?

Answer 2

splanchnic layer of later plate mesoderm

Question 3

where do extraembryonic blood vessels form?

Answer 3

yolk sac mesoderm cells

Question 4

which area of the embryo (cranial and lateral to prochordal plate) does the heart form?

Answer 4

cardiogenic area

Question 5

where are angiogenic cell clusters found?

Answer 5

coelomic area

Question 6

transverse and longitudinal folding is critical to the …

Answer 6

positioning of the heart

Question 7

which structures allow blood to flow into the heart?

Answer 7

RL sinus venosus

Question 8

how many atria do adults have?

Answer 8

two

Question 9

how many ventricles do adults have?

Answer 9

two

Question 10

explain the process of lateral folding

Answer 10

endocardial heart tubes brought to midline positions where they fuse and separate from guttube (by breakdown of dorsal mesocardium) and suspends freely

Question 11

what two structures “grow immensely” and drive the positioning of the mature heart?

Answer 11

left ventricle and bulbis cordis

Question 12

adult left ventricle derived from …?

Answer 12

primitive ventricle and bulbus/conus cordis

Question 13

adult right ventricle derived from …?

Answer 13

bulbus/conus cordis

Question 14

aortic arch forms the …

Answer 14

dorsal LR aorta

Question 15

aortic arch is associated with what …?

Answer 15

pharyngeal arches

Question 16

why are cardiac defects tolerated so well?

Answer 16

not a major source of gas exchange in the fetal period (the placenta is)

Question 17

right atrium of the heart derived from?

Answer 17

R horn of the sinus venosus

Question 18

left atrium of the heart derived from?

Answer 18

portion of primitive pulmonary veins

Question 19

primitive atria derived from …?

Answer 19

portions of both atria (RL)

Question 20

path between septum primum and septum secundum is called the …

Answer 20

foramen ovale

Question 21

closure of the foramen primum results from the fusion of ….

Answer 21

septum primum and endocardial cushion

Question 22

why is the foramen ovale important?

Answer 22

permits blood flow from RL atria during fetal development

Question 23

at birth, which side of the lungs has the most pressure?

Answer 23

left

Question 24

a complete interatrial septum is made from …?

Answer 24

septum primum and septum secundum

Question 25

if there is R hypertension, how does blood flow?

Answer 25

right to left

Question 26

right to left shunt of blood possible, cyanosis may result

Answer 26

patent foramen ovale

Question 27

“physical hole”; mixing of RL blood

Answer 27

secundum atrial septal defect

Question 28

what two structures are found in the outflow region?

Answer 28

bulbus cordis and truncus arteriosus

Question 29

which septum is the “spiraling septum”?

Answer 29

aortic pulmonary septum

Question 30

why are facial and cardiovascular defects typically found together?

Answer 30

they are both neural crest cell derived

Question 31

the interventricular septum is composed of … ?

Answer 31

muscular and membranous part (fused w/ endocardial cushions)

Question 32

name the space between the endocardial cushions and the muscular septum that allows open communication up until the 7th week

Answer 32

interventricular foramen