Exam 2 Lecture - Development of the Cardiovascular System Flashcards Preview

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Flashcards in Exam 2 Lecture - Development of the Cardiovascular System Deck (62)
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1
Q

Where does the right atrium receive blood from?

A

the caudal and cranial vena cava; system return

2
Q

Where does the right ventricle send blood?

A

pushes it out through the pulmonary trunk and arteries to the lungs; pulmonary outflow

3
Q

Where does the left atrium get blood from?

A

the pulmonary veins; pulmonary return

4
Q

Where does the left ventricle send blood?

A

to the aorta, out to the rest of the body; systemic outflow

5
Q

What is special about the relationship of the pulmonary trunk and the aorta?

A

they wrap around each other

6
Q

True or False: the heart is the first organ to differentiate and the first organ to function

A

False: it is only the first organ to function

7
Q

At what important developmental event does the 1st heat beat happen at?

A

the closure of the neural tube

8
Q

In early development, what is the function of the heart?

A

move blood from extra embryonic vessels through the embryonic circulatory system

9
Q

What is the heart in the first stage of embryonic development?

A

a cardiogenic plate

10
Q

Where is the cardiogenic plate located at the beginning of its development?

A

outside of the embryo proper

11
Q

What process brings the cardiogenic plate inside of the embryo proper?

A

body folding brings the cardiogenic plate inside by turning it 180 degrees

12
Q

Where is the heart located in early development?

A

where the mandible is

13
Q

What causes the first heart beat?

A

the two heart tubes within the cardiogenic plate spontaneously contract and then fuse

14
Q

What is the pump of the early development heart considered?

A

simple peristaltic pump - contraction goes from caudal (inflow) to cranial (outflow)

15
Q

What are the primitive heart regions?

A

sinous venosus, atrium, ventricle, bulbus cordis, truncus arteriosus, and bulbus cordis

16
Q

What does the sinous venosus give rise to?

A

the left part becomes the coronary sinus, the right part becomes part of the wall of the atrium

17
Q

What does the atrium become?

A

the left and right atria

18
Q

What does the bulbus cordis become?

A

part of the right and a small part of the left ventricle

19
Q

What does the truncus arteriosus and bulbs cordis become?

A

the ascending aorta and the pulmonary trunk

20
Q

What does the ventricle become?

A

part of the right and left ventricle

21
Q

What causes the rotation in the heart (cardiac loop)?

A

one part of the embryologic heart will grow faster than the other part causing rotation

22
Q

How does the cardiac loop affect the location of the atria?

A

it helps it become dorsal to the ventricle

23
Q

How does the cardiac loop affect the location of the ventricle?

A

puts the ventricle next to the bulbus cordus

24
Q

How are the atrium and the ventricle connected?

A

via the atrioventricular canal

25
Q

How are the endocardial cushions formed?

A

the heart begins to form a constriction between the atrium and the ventricle

26
Q

What is the purpose of the endocardial cushion?

A

it divides the atrioventricular canal into two different sections

27
Q

Why is atrial partitioning important?

A

because it will ensure that the developing animal can move blood from the right atrium to the left atrium

28
Q

What are the structures that develop from atrial partitioning?

A
Septum 1
Foramen 1
Foramen 2
Septum 2
Oval foramen
29
Q

What is the first structure to develop?

A

septum 1

30
Q

What is the opening between septum 1 and the endocardial cushions called?

A

foramen 1

31
Q

What happens to foramen 1?

A

IT GETS OBLITERATED as septum 1 continues to grow down and meet the endocardial cushion

32
Q

What forms foramen 2?

A

an area of apoptosis

33
Q

The septum 2 forms after foramen 2 forms, what forms within septum 2?

A

Foramen 3 (oval foramen)

34
Q

How does blood flow beginning at the right atrium and ending at the left atrium in the embryonic heart?

A

flows from the right atrium through the oval foramen in between septum 1 and 2 and flow through foramen 2

35
Q

Why is the pulmonary trunk and the aorta twisted around each other?

A

because during development, the endocardial cushions fuse together, but as you move down the atrioventricular canal, they are oriented differently causing a spiral septum dividing the outflow

36
Q

What 3 things are vital to closing the intraventricular foramen?

A

the intraventricular septum, the spiral septum, the endocardial cushion

37
Q

Ectopic cordis

A

when the heart is in an abnormal location

38
Q

dextrocardia

A

the heart of the adult is a mirror image of normal

commonly seen in situs inversus

39
Q

What are 3 common valvular defects?

A

stenosis, insufficiency, dysplasia

40
Q

What are the defects associated with tetralogy of fallot?

A

intraventricular foramen is still open, pulmonary stenosis, dextroposition of aorta, right ventricular hypertrophy

41
Q

What does embryo mean?

A

early development when we do not know what it is going to become

42
Q

What does fetus mean?

A

once we know what it is going to become

43
Q

How does blood flow through the fetus (right atrium route)?

A
Umbilical vein (high O2) to either
(a) through the mass of the liver or  
(b) through the ductus venosus
to the caudal vena cava (low O2) to 
 the right atrium, through the oval foramen, between septum 1 and 2, through foramen 2, into the left atrium, to the left ventricle, out of the aorta, to the head, back to the aortic arch to the umbilical artery
44
Q

If the blood does not go to the right atrium, how does the blood flow?

A

to the right ventricle, joined by the blood returning from the cranial vena cava, to the pulmonary trunk to the ductus arteriosus to the aorta to the aortic arch to the umbilical artery

45
Q

What is considered things that the newborn has to ‘deal with’ at birth?

A

umbilical artery, ductus arteriosus, oval foramen, ductus venosus, umbilical vein

46
Q

What happens to the umbilical artery at birth?

A

it is crushed when born and collapses and closes off

47
Q

What happens to the ductus arteriosus at birth?

A

longest process of closure; a decrease in blood pressure, loss of PGE2 from the placenta, increase of oxygen concentration causing it to close

48
Q

What happens to the oval foramen after birth?

A

an increase in blood pressure to the left atrium, a decrease of blood pressure of the right atrium; pushes septum 1 into septum 2 and hits off the flow of blood from the right atrium to the left causing it to close

49
Q

How does the ductus venosus close?

A

usually closed at the time of birth, if not it closes like the umbilical vain; no blood flow, decrease of PGE2

50
Q

How does the umbilical vein close?

A

shuts down when the vein no longer has blood flow from the placenta because the placenta provides PGE2

51
Q

What is PGE2?

A

a potent vasodilator; when the production stops, the vein constricts

52
Q

What are the structures of the cardiac loop in the basic embryo?

A

ventral aorta, dorsal aorta, aortic arches

53
Q

How many aortic arches are there and what are their numbers?

A

5; 1,2,3,4,6

54
Q

Why is there no 5th aortic arch?

A

because it rarely develops in mammals, found in lower vertebrates

55
Q

What happens to the 1st and 2nd arches during development?

A

they degenerate

56
Q

What is the function of the 3rd aortic arch during development?

A

to supply the head

57
Q

What is the function of the 4th aortic arch during development?

A

to supply the rest of the body

58
Q

What does the 3rd aortic arch contribute to?

A

the internal carotid artery

59
Q

What does the left 4th aortic arch become incorporated into?

A

the aortic arch of the adult

60
Q

What does the right 4th aortic arch become incorporated into?

A

the right subclavian

61
Q

What does the right 6th aortic arch become incorporated into?

A

nothing, it degenerates

62
Q

What does the left 6th aortic arch become incorporated into?

A

the ductus arteriosus