Final Embryo - Heart Development Flashcards Preview

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Flashcards in Final Embryo - Heart Development Deck (64):
1

This is when splanchnic mesoderm cells cluster together to form a solid horseshoe-shaped cord of endothelial cells

vasculogenesis

2

Where does the horseshoe shaped endothelial cord form

within cardiac mesoderm

3

True or False
The cardiac system is the last system that becomes functioning in an embryo

False; it is the first functioning system

4

When does the horseshoe shaped endothelial cord hollow out

in the 4th week

5

How does the horseshoe shaped endothelial cord form a single heart tube

via the folding of the lateral sides of the endothelial tube in ventrally and medially approaching each other at the midline to fuse

6

Upon lateral folding to form the heart tube, what else fuses

paired dorsal aortae

7

This repositions the developing heart and pericardial cavity

head folding

8

prior to head folding, the heart is located where

rostral to oropharyngeal membrane
ventral to pericardial cavity

9

post head folding, the heart is located where

caudal to oropharyngeal membrane
dorsal to pericardial cavity
ventral to foregut
rostral to spetum transversum (diaphragm)

10

This acts like a "hinge" in head folding to reposition the heart

oropharyngeal membrane

11

As the dorsal mesocardium degenerates (day 22), what forms

transverse pericardial sinus
space behind the aorta and pulmonary trunk

12

What are the layers of the primitive heart tube from deep to superficial

endothelium
cardiac jelly
myocardium
epicardium
pericardial cavity
parietal pericardium

13

All of the layers of the primitive heart tube are derived from what

splanchnic mesoderm

14

At what day does the heart begin to beat

Day 22 or 23

15

What are the dilations of the primordial heart tube

sinus venosus
primordial atrium
primordial ventricle
conus cordis
truncus arteriosus

16

The sinus venous forms what structures in adults

coronary sinus
sinus venarum

17

The primordial atrium forms what structures in adults

right and left auricles
portions of the atria

18

The primordial ventricle forms what structure in adults

left ventricle

19

The conus cordis forms what structures in adults

outflow tract of the ventricles
caudal (proximal) portion of forms right ventricle

20

The truncus arterioles forms what structures in adults

pulmonary trunk
aorta

21

What to primitive structures form the bulbs cordis

truncus arteriosus
conus cordis

22

This is between the primordial atrium and primordial ventricle

atrioventricular sulcus
atrioventricular canal

23

This is between the primordial ventricle and conus cordis

bulboventricular sulcus
primary interventricular foramen

24

Where does the blood flow after the bulbs cordis

aortic sac then pharyngeal arch arteries

25

When does the formation of the cardiac loop/heart folding takes place when

Days 22-28

26

As the heart fold, which direction does it move

its cranial end will shift ventrally, caudally and to the right
its caudal end will shift dorsally and superiorly

27

What is the blood circulation through the primordial heart

sinus venosus
primordial atrium
atrioventricular canal
left (primordial) ventricle
interventricular foramen
right ventricle
conus cordis
truncus arteriosus
aortic sac
pharyngeal aa.
dorsal aortae

28

Partioning of he primordial heart takes place when

Days 27-37

29

In partitioning the atrioventricular canal endothelial cells near the AV junction do what

revert to mesenchymal state, invade the underlying cardiac jelly, and proliferate

30

What does the endothelial cells near the AV junction cause

it cause the endocardium to bulge out into the AV canal from its dorsal and ventral walls

31

The dorsal and ventral endocardial walls develop and fuse together forming what

atrioventricular septum that divide the atrioventricular canal into right and left AV canals

32

Is the portioned AV canal completely sealed off?

No

33

Partioning of the primordial atrium involved what

forming two septa that will fuse together to from the interatrial septum

34

What are the two septa of the intertribal septum

septum primum (first)
septum secundum (second)

35

This develops from the roof of the primordial atrium as the thin, moon-shaped membrane

septum primum

36

This grows inferiorly to fuse with the endocardial cushions

spetum primun

37

The opening between the inferior edge of the septum primun and the endocardial cushions is what

foramen primun

38

As the septum primum fuses with the endocardial cushions and the foramen primum closes, what forms

holes in the center of the septum primun via apoptosis
forming foramen secundum

39

As the foramen secundum is formed, what beings to develop to the right

septum secundum

40

The septam secundum grows inferiorly and develops an opening called what

foramen ovale (oval foramen)

41

Where does blood flow via the foramen ovale and foramen secundum

blood now passed from right to left atrium

42

After birth, what happens to the foramen ovale

it closes off and there is no blood flow between atria

43

What forms the valve of the foramen ovale

the septum primum; the cranial portion degenerates

44

After birth, what happens to the valve of the foramen ovale

The blood pressure of the left atrium exceeds the right atrium which pushed the valve closed and they fuse which closes of the foramen

45

What does the closing of the foramen oval create

fossa ovalis; a depression in the wall of the right atrium

46

The muscular portion of the IV septum grows where

cranially toward the AV septum, but does not fuse with it

47

The opening between the right and left ventricles is what

the interventricular foramen

48

The membranous portion of the IV septum is derived from what

the mesenchyme of the endocardial cushion tissue

49

This develops at different orientations through the length of the conus cordis and truncus arteriosus

endocardial cushions

50

The endocardial cushions of the bulbus cordis fuse with each other forming what

a twisting aorticopulmonary septum that divides the outflow tract into pulmonary trunk and aorta

51

What is the most common congenital heart defect

ventricular septal defect

52

What is a ventricular septal defect

failure of IV septum to completely form

53

What is the anatomical basis for a ventricular septal defect

in most cases (80%) the membranous portion of the septum fails to form, but can also be the muscular portion

54

What are some of the main transpositions of great vessels

the aorticopulmonary septum grows straight instead of spiraling
aorta arises from right ventricle
pulmonary trunk arises from left ventricle

55

What is the tetralogy of fallot

interventricular septal defect
hypertrophy of right ventricle
overring aorta
pulmonary stenosis

56

Aorticopulmonary septum divides what

outflow tract unequally, resulting in stenosis of pulmonary trunk and an overriding aorta

57

What 3 pairs veins drain into the sinus venosus

vitelline (from yolk sac)
umbilical (deoxygenated blood)
common cardinal (body of embryo)

58

Originally, the sinus venous opens where

directly into the central dorsal wall of the primordial atrium

59

Blood flow from the heart gradually shifts to the right side due to what

remodeling of the vitelline, umbilical, and anterior cardinal veins

60

What is the result of the blood flow remodeling to the right

the right horn of the sinus venosus becomes larger than the left

61

The right horn of the sinus venosus becomes what

smooth walled portion of the right atrium (sinus venarum)

62

The left horn of the sinus venosus becomes what

the coronary sinus that drains into the right atrium

63

As the heart grows, the primordial pulmonary veins and portions of its branches are incorporated where

into the dorsal aspect of the heart, forming the smooth-walled portion of the left atrium

64

The aortic sac becomes what in adults

ascending aorta