CARDIOVASCULAR- EMBRYOLOGY

Question 1

What does the following embryonic structure of the heart give rise to: truncus arteriosus?

Answer 1

Ascending aorta and pulmonary trunk

Question 2

What does the following embryonic structure of the heart give rise to: bulbus cordis?

Answer 2

Smooth parts of left and right ventricle

Question 3

What does the following embryonic structure of the heart give rise to: primitive atria?

Answer 3

Trabeculated part of the left and right atria

Question 4

What does the following embryonic structure of the heart give rise to: primitive ventricle?

Answer 4

Trabeculated part of the left and right ventricles

Question 5

What does the following embryonic structure of the heart give rise to: primitive pulmonary vein?

Answer 5

Smooth part of the left atrium

Question 6

What does the following embryonic structure of the heart give rise to: left horn of the sinus venosus?

Answer 6

Coronary sinus

Question 7

What does the following embryonic structure of the heart give rise to: right horn of the sinus venosus?

Answer 7

Smooth part of the right atrium

Question 8

What does the following embryonic structure of the heart give rise to: right common cardinal vein and right anterior cardinal vein?

Answer 8

SVC

Question 9

In embryonic development, what is the first functional organ?

Answer 9

Heart

Question 10

When does the heart start to beat?

Answer 10

4 weeks

Question 11

What can a defect in left-right dynein result in? What disease is this seen in?

Answer 11

Dextrocardia, as seen in Kartagener Syndrome

Question 12

Outline the septation of the atria.

Answer 12

1) Septum primum grows toward endocardial cushions (forming the “foramen primum”)
2) Superior portion of the septum primum regresses, forming the “foramen secundum”
3) Septum secundum begins to develop
4) Septum primum and septum secundum overlap forming the FORAMEN OVALE

*Foramen ovale usually closes at birth b/c of an increase in left atrial pressure

Question 13

What is a patent foramen ovale?

Answer 13

Failure of the septum primum and secundum to fuse after birth

Question 14

In extreme cases (and if untreated), what can a patient foramen ovale cause?

Answer 14

Paradoxical emboli

Question 15

Outline the septation of the ventricles.

Answer 15

1) Muscular ventricular septum forms
2) Aorticopulmonary septum rotates and fuses with muscular ventricular septum
- Forms the membranous interventricular septum
- Closes the interventricular foramen
3) Endocardial cushions develop contributing the the interventricular septum

Question 16

Where do most ventricular septal defects occur (VSD)?

Answer 16

Membranous portion of the interventricular septum

Question 17

What are the heart valves derived from?

Answer 17

Endocardial cushions

Question 18

Specifically, what are the aortic and pulmonary valves derived from?

Answer 18

Endocardial cushions of the outflow tract

Question 19

Specifically, what are the mitral and tricuspid valves derived from?

Answer 19

Endocardial cushions of the AV canal

Question 20

Where does fetal erythropoiesis take place? Use a mnemonic to recall.

Answer 20

Young Liver Synthesizes Blood

1) Yolk sac (3-8 weeks)
2) Liver (6 weeks to birth)
3) Spleen (10-18 weeks)
4) Bone marrow (18 weeks to adult)

Question 21

What is fetal Hemoglobin?

Answer 21

HbF

Question 22

Describe the composition of fetal Hb.

Answer 22

2x alpha and 2x gamma

Question 23

What is adult Hemoglobin?

Answer 23

HbA

Question 24

Describe the composition of adult Hb. What is a mnemonic to recall this information?

Answer 24

2x alpha and 2x beta

Alpha always; Gamma goes: Becomes beta

Question 25

How does HbF compare to HbA?

Answer 25

Higher oxygen affinity

Question 26

Why does HbF have a higher oxygen affinity than HbA? What is the functional outcome of HbF having higher oxygen affinity?

Answer 26

Less affinity of 2,3-BPG *Allows HbF to extract oxygen from maternal HbA, across the placenta*

Question 27

What blood vessel carries blood from the placenta to the fetus?

Answer 27

Umbilical vein

Question 28

What allows blood from the placenta to bypass the liver?

Answer 28

Ductus venosus

Question 29

Once blood gets from the placenta/ umbilical vein to the RA, where can it go?

Answer 29

1) Into RV like normal | 2) Through the FORAMEN OVALE into the LA

Question 30

What is the function of the foramen ovale?

Answer 30

Allows blood to bypass the fetal lungs

Question 31

What is the ductus arteriosus?

Answer 31

Fetal connection between the pulmonary trunk and aorta

Question 32

What is the function of the ductus arteriosus?

Answer 32

Allows blood that enters the RV/ pulmonary artery to also bypass the fetal lungs

Question 33

What does the umbilical vein become in the adult?

Answer 33

Ligamentum teres hepatis (in the Falciform Ligament)

Question 34

What do the umbilical arteries become in the adult?

Answer 34

Medial umbilical ligaments

Question 35

What does the ductus arteriosus become in the adult?

Answer 35

Ligamentum arteriosum

Question 36

What does the ductus venosus become in the adult?

Answer 36

Ligamentum venosum

Question 37

What does the formaen ovale become in the adult?

Answer 37

Fossa ovalis

Question 38

What does the allantois become in the adult?

Answer 38

Median umbilical ligament

Question 39

What does the notochord become in the adult?

Answer 39

Nucleus pulposus of the intervertebral discs

Question 40

What are the two major branches of the RCA?

Answer 40

Marginal artery | Posterior descending artery

Question 41

What does the marginal artery supply?

Answer 41

Right ventricle

Question 42

What does the PDA supply?

Answer 42

Posterior 1/3 of IV septum and posterior ventricular walls

Question 43

What are the major branches of the LCA?

Answer 43

Left circumflex | Left Anterior Descending

Question 44

What artery supplies the SA and AV nodes?

Answer 44

RCA

Question 45

What can a RCA infarct cause?

Answer 45

Bradycardia or heart block

Question 46

What is right-dominant circulation?

Answer 46

PDA arises from RCA

Question 47

What is left dominant circulation?

Answer 47

PDA arises from Left Circumflex

Question 48

What is codominant circulation?

Answer 48

PDA arises from both RCA and Left Circumflex

Question 49

What coronary artery is most commonly occluded?

Answer 49

LAD

Question 50

When does coronary blood flow peak?

Answer 50

Early diastole

Question 51

What is the most posterior part of the heart?

Answer 51

Left atrium

Question 52

What can happen with enlargement of the left atrium?

Answer 52

1) Dysphagia--borders the esophagus | 2) Hoarseness--pressure on the recurrent laryngeal