4 Embryo Development of Heart

Question 1

parts of bulbus cordis

Answer 1

conus cordis truncus arteriosus

Question 2

aortic sac

Answer 2

ascending aorta

Question 3

truncus arteriosus

Answer 3

roots & pulmonary portions of aorta and pulmonary trunk

Question 4

conus cordis

Answer 4

outflow tracts of ventricles

Question 5

proximal segment of bulbus cordis

Answer 5

right ventricle

Question 6

primordial ventricle

Answer 6

left ventricle

Question 7

primordial atrium

Answer 7

left and right auricles & trabeculated portions of the atria

Question 8

right horn of sinus venosus

Answer 8

sinus venarum (smooth-walled portion of R atrium)

Question 9

left horn of sinus venosus

Answer 9

coronary sinus

Question 10

primordial pulmonary v + its branches

Answer 10

smooth-walled portion of left atrium

Question 11

In what week does heart development begin?

Answer 11

Week 3. Solid, then canalizes at Week 4.

Question 12

Tissue responsible when heart begins to form?

Answer 12

Cardiogenic mesoderm form solid, horseshoe-shaped endothelial cord.

Question 13

What creates primitive heart tube?

Answer 13

Lateral body folding (ventrally and medially, to approach midline).

Question 14

How does head folding reposition heart and pericardial cavity? Before head fold

Answer 14

Rostral to oropharyngeal membrane Ventral to pericardial cavity

Question 15

How does head folding reposition heart and pericardial cavity? After head fold

Answer 15

Caudal to oropharyngeal membrane Dorsal to pericardial cavity Ventral to the foregut Rostral to the septum transversum/diaphragm

Question 16

Fate of dorsal mesocardium?

Answer 16

Degenerates to transverse pericardial sinus

Question 17

What day does heart beat begin?

Answer 17

Day 22 or 23

Question 18

When does heart folding occur?

Answer 18

Day 22-28

Question 19

Describe how folding heart tube creates cardiac loop.

Answer 19

Cranial: CRV caudally, right, ventrally Caudal: DS dorsally, superiorly

Question 20

Circulation through primordial heart!

Answer 20

Yay! :)

Question 21

VSD

Answer 21

Ventricular septal defect Most common Membranous portion of IV septum fails to form.

Question 22

Transposition of great vessels

Answer 22

Aorticopulmonary septum grows straight instead of spiraling

Question 23

Tetralogy of Fallot

Answer 23

Aorticopulmonary septum divides outflow tract unequally. INTERnational: VSD H: hypertrophy of right ventricle O: overriding aorta PancakeS: pulmonary stenosis

Question 24

atrioventricular septum

Answer 24

Endothelial cells revert to mesenchymal state. Endocardial cushions fuse. Divide atrioventricular canal into R + L AV canals.

Question 25

interatrial septum

Answer 25

fusion of septum primum and septum secundum

Question 26

Blood flow before and after birth.

Answer 26

Before: R to L atrium through foramen ovale. After: Foramen ovale becomes fossa ovalis (valve of foramen ovale against septum secundum due to high pressure in L atrium)

Question 27

interventricular septum

Answer 27

membranous portion from mesenchyme of endocardial cushion tissue.

Question 28

aorticopulmonary septum

Answer 28

Endocardial cushions throughout conus cordis and truncus arteriosus. Later fuses inferiorly with membranous IV septum

Question 29

Outflow tract

Answer 29

Pulmonary trunk (right ventricle) Aorta (left ventricle)

Question 30

Smooth portions of R and L atrium

Answer 30

R: sinus venorum, from right horn of sinus venosus L: pulmonary veins

Question 31

ID structure.

Derivative?

Divided by?

Answer 31

truncus arteriosus

–> pulmonary trunk & ascending aorta

divided by aorticopulmonary (spirling) septum

Question 32

ID opening.

Answer 32

foramen ovale (oval foramen)