Lecture 13 - Heart Development

Question 1

Where does blood vessel formation begin? When?

Answer 1

extraembryonic splanchnic mesoderm; day 17

Question 2

What do hemangioblasts form

Answer 2

early embryonic erythrocytes and macrophages

Question 3

What is the early source of hematopoietic cells in the body

Answer 3

liver

Question 4

what allows the liver to produce the full range of myeloid and lymphoid cells

Answer 4

cells from the AGM region

Question 5

where do the AGM cells go after the liver

Answer 5

lymph organs and bone marrow

Question 6

where are blood cells made starting at day 17

Answer 6

yolk sac mesoderm

Question 7

when is the liver colonized so that it can make blood cells

Answer 7

23 days and continues to birth

Question 8

when do the AGM cells go to the liver? where are they from?

Answer 8

begins day 27-40; dorsal aorta

Question 9

when does bone marrow begin developing cells

Answer 9

10.5 weeks

Question 10

what leads the newly forming blood vessels where they need to go

Answer 10

tip and sprout cells

Question 11

where doe the newly forming blood veseels collect

Answer 11

extraembryonic splanchnic mesoderm and between somites (paraxial mesoderm)

Question 12

what is intussuception

Answer 12

splitting 1 vessel into 2

Question 13

what are angiomas

Answer 13

abnormal blood vessel and capillary growths that are usually benign

Question 14

what can angiomas sometimes affect

Answer 14

eyesight

Question 15

what is normally inhibiting the formation of the angiogenic clusters

Answer 15

neural cord

Question 16

when does the primary heart field normally form

Answer 16

day 19

Question 17

what causes the heart tubes to unite

Answer 17

lateral folding

Question 18

what aligns the heart correctly in left/right? up/down?

Answer 18

lateral folding; cranial/caudal folding

Question 19

what does the proepicardial organ form? what is it made of

Answer 19

visceral mesocardium; dorsal mesocardium

Question 20

Right after the heart tubes fold, how is the heart arranged

Answer 20

artia are below the ventricles

Question 21

what veins go into the sinus horns

Answer 21

umbilical vein - oxygenated blood from placenta
vitelline vein - yolk sac drainage
common cardinal vein - lower body/everything else

Question 22

when do cardiac twitches occur? rhythmic contractions?

Answer 22

22; 24

Question 23

what is at the future site of the AV node normally?

Answer 23

R sinus horn

Question 24

what normally causes outflow anomalies

Answer 24

insufficient cardiac looping

Question 25

what allows the secondary heart field to develop

Answer 25

lateral folding moves it farther away from neural tube's inhibitory signals

Question 26

what cell type modulates heart development

Answer 26

NCC with FGF8

Question 27

what does the primary heart field form

Answer 27

l/r atrium, l vent

Question 28

what does the secondary heart field form

Answer 28

RV and outflow trunk

Question 29

what does the formation of primary and secondary heart fields depend on

Answer 29

retinoic acid

Question 30

what is reverse cardiac looping called

Answer 30

ventricular inversion (LV is on the right)

Question 31

what is situs invertus

Answer 31

total body mirroring

Question 32

what is situs ambiguous

Answer 32

partial body mirroring

Question 33

what is visceroatrial heterotaxia

Answer 33

heart on right and normal GI

Question 34

what does the left sinus horn become

Answer 34

coronary sinus

Question 35

what does the right common cardinal vein become

Answer 35

superior vena cava

Question 36

what does the right vitelline vein become

Answer 36

inferior vena cava

Question 37

the smooth portion of the internal RA is called the

Answer 37

sinus venarum

Question 38

what is the border between the sinus venarum and the RA

Answer 38

crista terminalis

Question 39

what is the process by which the heart normally enalrges

Answer 39

differential growth

Question 40

what do the interatrial septum and interventricular septum normally get filled in by

Answer 40

they are primarily muscle but cushion tissue fills in the rest

Question 41

of what origin is cushion tissue

Answer 41

endocardial

Question 42

where do the pulmonary trunk and aorta get their cushion tissue

Answer 42

endocardial cells and ectodermal neural crest

Question 43

what happens when the cushion cells don't form the barrier

Answer 43

persistent av canal

Question 44

what pathology would you expect with persistent av canal

Answer 44

pulmonary htn, exercise intolerance, SOB, cardiac congestion, increased risk of endocarditis

Question 45

what is persistent AV canal often linked to

Answer 45

down syndrome

Question 46

which septum forms first

Answer 46

septum primum

Question 47

what time does the septum primum form

Answer 47

33 days

Question 48

when does the septum secondum form

Answer 48

6th week (40 days)

Question 49

what does the foramen ovale form in

Answer 49

the septum secondum

Question 50

where are the holes in the two septa in relation to one another

Answer 50

foramen ovale (septum secondum) is lower

Question 51

what keeps the foramen ovale closed in adults

Answer 51

higher pressure in the left A

Question 52

what are the common atrial septum defects

Answer 52

excessive resorption of septum primum diminished septum secundum ostium primum defect

Question 53

what is a lower osteum defect

Answer 53

osteum primum defect

Question 54

what causes double outlet RV

Answer 54

insufficient shifting of AV septum or cardiac looping

Question 55

what are the symptoms of double outlet right ventricle

Answer 55

show within days - cyanosis - breathlessness - murmur - eventually, poor weight gain

Question 56

what is double outlet RV

Answer 56

pulmonary trunk and aorta both exit RV

Question 57

what does the truncus arteriosis split into

Answer 57

pulmonary trunk and aorta

Question 58

how do we ensure that we get complete septation of the outflow tract

Answer 58

1. have the conal truncal ridges extend completely | 2. downgrowth from the atrioventricular cushion tissues

Question 59

if NCC don't migrate what effects does that have on cardiopulmonary system

Answer 59

malformation of the heart and great vessels

Question 60

craniofacial deformations and cardiac issues are both related to what

Answer 60

NCC

Question 61

what are the most common heart defects

Answer 61

VSD

Question 62

what do VSD causes

Answer 62

L-> R shunting

Question 63

what are the symptoms of VSD

Answer 63

- pulmonary congestion - RV hypertonicity - pulmonary htn

Question 64

what is persistent truncus arteriosus

Answer 64

the pulmonary trunk and aorta don't split

Question 65

what causes persistent truncus arteriosus

Answer 65

lack of conal truncal ridges

Question 66

what is the most common cause of cyanosis at birth

Answer 66

tetralogy of fallot

Question 67

what is the tetralogy of fallot

Answer 67

pulmonary stenosis RV hypertrophy overriding aorta VSD

Question 68

what does transposition of great vessels and pulmonary valvular atresia cause

Answer 68

immediate cyanosis

Question 69

what is tranposition of great vessels

Answer 69

RV gets aorta; LV gets pulmonary trunk

Question 70

what is pulmonary valvular atresia

Answer 70

lack of formation of the pulmonary semilunar valve out of the RV

Question 71

what things cause RV hypertrophy

Answer 71

aortic valvular atresia tetralogy of fallot hypoplastic left ventricle

Question 72

what causes aortic valvular stenosis

Answer 72

congenital pathological - rhematic fever degenerative (over time)

Question 73

what cardiac defect affects males more than females

Answer 73

aortic valvular stenosis

Question 74

what heart defect is associated with the development of aortic aneurysms

Answer 74

bicuspid aortic valves

Question 75

what is bicuspid aortic valve

Answer 75

the semilunar valve leaving the LV is bicuspid instead of tricuspid; expect symptoms similar to aortic valve stenosis

Question 76

what heart defect is inheritable

Answer 76

bicuspid aortic valve

Question 77

what is tricuspid atresia

Answer 77

now way from the RV to the pulmonary trunk

Question 78

what is hypoplastic left ventricle

Answer 78

``` LV is underdeveloped Mitral valve is not formed or small Aortic valve is not formed or small Ascending portion of aorta is underdeveloped heart works as a single ventricle unit ```