Heart Development

Question 1

what type of embryonic tissue is used for vasculogenesis

Answer 1

bv are made from mesenchyme

Question 2

hemangioblast differentiate into

Answer 2

hematopoietic progenitor cells and endothelial precursor cells

Question 3

embryonic hematopoietic cells reside in where at day 23? generate what?

Answer 3

liver primordia

embryonic erythrocytes, macrophages, megakaryocytes

Question 4

definitive hematopoietic stem cells are programmed from? Once signaled they mature into?

Answer 4

hemogenic endothelial cells of dorsal aorta in aortic-gonadal-mesoephric region

myeloid an lymphoid stem cells (for lymph organs and bone marrow)

Question 5

other than the agm region, is bv formation coupled with hematopoiesis?

Answer 5

NO

Question 6

what are endothelial precursor cells differentiate from

Answer 6

intraembryonic splanchnic mesoderm

paraxial mesoderm

Question 7

long tubes (angioplastic plexus) grows by

Answer 7

cont proliferation of endothelial precursor cells
angiogenesis (bud/sprout of new vessels from existing)
intussusception (splitting)
recruitment of new mesodermal cells

Question 8

excessive growth of a small capillary network

Answer 8

capillary hemangioma

Question 9

excessive growth of venous sinuses

Answer 9

cavernous hemangioma

Question 10

angiomas

Answer 10

abnormal bv/ lymphatic growth via vasculogenic process

Question 11

first heart field

Answer 11

cardiac crescent

epc clusters in horseshoe shape in cardiogenic area of intraembryonic splanchnic mesoderm

Question 12

during folding, epc differentiate into what

Answer 12

(median growth) endothelial cells forming 2 primitive endocardial tubes
then (lateral folds) brings /fuses tubes together

Question 13

dorsal aorta is dragged ventrally during folding forming

Answer 13

first aortic arch

Question 14

inflow to primitive heart?

Answer 14

common cardinal veins (venous blood from head and trunk)
vitelline veins (venous blood from gut)
umbilical veins (O2 blood from mom)

Question 15

primary heart tube wall consists of?

Answer 15

endocardium, cardiac jelly, myocardium

Question 16

first rhythmic contraction, blood starts flowing?

Answer 16

day 22, day 24

Question 17

sinus venosus is made of?

Answer 17

confluent right and left sinus horns

Question 18

flow of how blood enters and exits primodia heart

Answer 18

sinus venosus -> primitive atrium -> atrioventricular region ->primitive ventricle -> outflow tract (bulbus cordis) -> aortic sac or root

Question 19

what delineates early LV (primitive ventricle) from future right ventricle

Answer 19

constriction called inter-ventricular sulcus

Question 20

what is an aortic sac or root

Answer 20

common confluens of pharyngeal arch bv

contributes to future aorta, pulm a, carotids etc

Question 21

what suspends the heart tube? what happens to it in the adult?

Answer 21

dorsal mesocardium
ruptures to form transverse sinus
remnants form proepicardial organ

Question 22

proepicardial organ forms?

Answer 22

epicardium (future visceral pericardium)

the cells migrate over myocardium

Question 23

in cardiac looping, initial outflow tract becomes?

Answer 23

right ventricle

Question 24

in cardiac looping, addition of myocardium at the cranial end forms?

Answer 24

conus arteriosus (prox outflow tract)
truncus arteriosus (distal outflow tract) later becomes aorta/pulm a

Question 25

what helps lengthen cardiac tube in cardiac looping?

Answer 25

second heart field | splanchnic mesoderm proliferation

Question 26

what maintains cardiogenic mesoderm proliferation and proper myocardial cell specification w/in 2nd heart field?

Answer 26

NCC dictates ncc, PA mesoderm, PA endoderm

Question 27

What happens to the sinus venosus opening?

Answer 27

shifts to right atrium due to cl, differentiate growth, changes in hemodynamics asymmetrical expansion of the l sinus horn = net shift of amt of blood returning to the right side

Question 28

left sinus horn becomes the?

Answer 28

coronary sinus

Question 29

R common cardinal vein becomes the?

Answer 29

superior vena cava

Question 30

R vitelline vein becomes the?

Answer 30

inferior vena cava

Question 31

R inferior valvular fold becomes the?

Answer 31

valve of inferior vena cava

Question 32

crista termnalis is?

Answer 32

jct between pectinate part of RA and sinus venarum

Question 33

part R sinus horn and R common cardinal v become?

Answer 33

SA node

Question 34

what makes the m interventricular septum and m atrial septum?

Answer 34

differential growth

Question 35

what forms new fibrous CT in AV region and conotruncal ridges of outflow tract?

Answer 35

endocardial cushion tissue from mesenchymal cells

Question 36

cushion cells are important for what?

Answer 36

fibrous septa formation, mesenchymal for anchoring heart valves and cardiac skeleton

Question 37

what makes conotruncial ridges?

Answer 37

ECT and NCC

Question 38

conus arteriosus contributes too?

Answer 38

pulm a and aorta to go out diff V | fibrous portion of interventricular septum

Question 39

what helps truncus arteriosus divide into pulm a and aorta?

Answer 39

aorticopulmonary septum

Question 40

septum primum is made from?

Answer 40

dorsal mesenchymal protrusion or spina vestibuli (mesodermal projection from caudal dorsal mesocardium) makes a hole near AV septum called ostium primum

Question 41

as cushion tissue close ostium primum, a new hole forms rostrally called?

Answer 41

ostium (foramen) secundum

Question 42

what overlaps ostium secundum? leaving what foramen?

Answer 42

septum secundum - much thicker to prevent back flow (L to right) only r to l foramen ovale

Question 43

blood from IVC in fetal cardiac blood flow goes into?

Answer 43

through foramen ovale into LA -> LV -> arteries

Question 44

blood from where goes through RA and RV in fetal cardiac blood flow goes into? how does it get to systematic arterial side?

Answer 44

SVC/coronary sinus, and part IVC ductus arteriosus

Question 45

interventricular septum is made of?

Answer 45

m part from ventricular wall and fibrous part from cushion tissue and proximal conotruncal ridges

Question 46

in partitioning outflow tract, what arches connect RV to lungs?

Answer 46

aortic arch VI

Question 47

in partitioning outflow tract, what arches connect LV to body?

Answer 47

aortic arch II and IV

Question 48

what is necessary for separate V to r and L?

Answer 48

shift of av canal to r side so AV cushion can fuse (myocardialization)

Question 49

conotruncal septum is formed from?

Answer 49

conotruncal ridge cushion tissue 180 spiral down toward ventricular septum formed by NCC and endocardial derived cushion tissue

Question 50

what is bulbus cordis?

Answer 50

outflow tract, makes the ventricular system