Key concepts: Heart Development Flashcards
what is seen from superior view of the embryo
cranial aspect
caudal aspect
cranial aspect
thickening of the mesoderm infront of the pro caudal plate
what does the heart tube develop from
the splanchnic layer of the lateral plate mesoderm
what does the endoderm release
vascular endothelial growth factors
VEGF’s
function of VEGF’s
stimulates the differentiation of the lateral plate mesoderm
outer and inner core
outer core
angioblast cells
form blood vessels and heart tube
inner core
hemocytoblast
form blood cells
heart tube and pericardial cavities from 2 to 1
lateral folding occurs
layers fuse
form one of each
what is the dorsal mesocardium
connects th pericardial cavity to the heart tube
layers of the heart tube from outside to inside
endocardium
cardiac jelly
myocardium
endocardium
made from angioblasts
cardiac jelly
made from myocardium secretion
myocardium
made from the cardiac monocytes
what occurs during cranial caudal folding
the heart moves into the cranial cavity
and the heart tube into the pericardial cavity
label the heart tube top to bottom
aortic sac
truncu arteriosus
bulbos cordis
primitive ventricles
primitive atria
sinus venosus
aortic sac
leaves via the dorsal aortae
trunks arteriosus
becomes the pulmonary trunk and the ascending aorta
bulbs cordis
right ventricles
right and left ventricular outflow tracts
primitive ventricle
left ventricle
primitive atria
left and right atrium
sinus venosus
have left and right horns
and 3 veins entering
label the veins entering the sinus venosus from lateral to medial
common cardinal
umbilical
viterline
heart formation
cardiac looping
AV canal formation
separating primtive atria
separate the BC and PV
inflow tracts
forming outflow tracts
semi-lunar valve formation
importance of cardiac looping
dependent on dyneins
if absent then the heart will bend left and not right
process of cardiac looping
TA and BC move down and to the right
PA moves to the left of the midline as TA and BC continue their movement
PA moves backwards and upwards
PA now up either side of the TA, attached to SV below the BC
SV allows cells to move into pericardial cavity and forms visceral pericardium
SV also allows cells to move into the “heart” forming the primitive conduction system
AV canal formation
AV sulcus between the PV and PA
neural crest cells forming dorsal and ventral endocardial cushions
cushions fuse to form the septum intermedium
2 canals form either side called the right and left AV canals
connected by annulus ring, valve flaps
cordinae tendinae come off
valvulpus apparatus becomes bi and tricuspid
separating primitive atria
septum primum tries to reach from the top to the septum intermedium
doesnt reach and forms hole known as ostium primum
septum prinum eventually closes the ostium prinum
another hole develops near the top which is the ostium secundum
more tissue grows to try and block the ostium secundum
there is still a small hole called the foramen ovale which eventually closes when born
some division formed so can classify as right and left atrium
separating the BC and PV
at the heart the apex develops muscular portion of interventricular septum
grows into the heart
space between= membranous portion of inter ventricular septum
comes from septum intermedium, closed gap
BC (one part of this) becomes the RV
PV becomes the LV
inflow tracts
between the PA and SV
all veins on the left horn of SV break down leaving left horn
umbilical horn degenerates leaving CCV and V
left horn shifts towards right horn and fuses before entering the SV
SV absorbed to become PA
left horn becomes coronary sinus
right common cardinal becomes superior vena cava
right vitelline vein to the inferior vena cava
outflow tract formation
neural crest cells form 2 truncal ridges in the TA and 2 bulbar ridges in the BC
also ridge in the middle of TA and BC
2 ridges one is dorsal and the other is ventral
meet in the middle
when ridges approach they spiral around central axis
ridges in the TA fuse to form the septum
ridges in the BC fuse to form septum
ridges in middle form septum
causes corkscrew of TA and BC to form aorticopulmonary septum
as blood moves LV through posterior portion of the septum crosses behind then infront of the top portion to form aortic arch
RV moves anterior, cross then posterior to form pulmonary trunk
structure rotates and splits structures
semi lunar valve formation
cross section at the bulbis cordis and conus cordis junction
neural crest cells form endothelial cushions (left right dorsal ventral)
during rotation vagination occurs
splits cushions left and right
then splits entirely into dorsal and ventral
still have full dorsal ventral cushion but half right and left cushion
dorsal= left ventricular outflow tract= aorta
ventral= right VOT= pulmonary trunk
forms semilunar valves
rotation occurs
right hand side post rotation
aortic SLV
LVOT
