cardiac embryology Flashcards
cephalocaudal folding goal
brings future heart (angiogenic cell cluster) into thoracic region
septum transversum becomes what structure
central tendon of diaphragm
lateral folding goal (and occurs what days)
brings L + R endocardial tubes (heart tubes) into the midline = now 1 heart tube
days 20-22
myocardium arises from what tissue
splanchnic (visceral lateral plate) mesoderm
myocardium secretes what
cardiac jelly (an acellular matrix)
during lateral folding what does endocardium line
inside of the heart tube
when does heart tube fusion occur
during lateral folding
parts of embryonic tube (day 20-22) by order from cranial to caudal
(cranial)
Truncus arteriosus
Bulbus cordis
Primitive ventricle
Common atria
Sinus venosus
(caudal)
truncus arteriosus forms what
proximal aorta & pulmonary trunk
bulbus cordis forms what
right ventricle / outflow tracts
primitive ventricle forms what
trabeculated parts of left ventricle
primitive (common) atria forms what
trabeculated parts of atria
sinus venosus forms what
smooth part of right atrium & coronary sinus
what branches off sinus venosus (order from right side of heart to left side of heart)
R common cardinal vein
R umbilical vein (degenerates)
R vitelline vein
L vitelline vein
L umbilical vein
L common cardinal vein
common cardinal vein function
brings blood from embryo
umbilical vein function
brings blood from placenta
vitelline vein function
brings blood from yolk sac
vitelline vein gives rise to what 4 veins
IVC
portal vein
SMV
hepatic v.
what is cardiac looping, why does it occur
heart tube folding until atria are cranial to ventricles
occurs bc heart grows faster than pericardial cavity
what direction do atria go during cardiac looping
rise up & twist left
what happens after cardiac looping
heart divides into 4 chambers via 4 types of septation
what days do the 4 types of septation occur
days 28-60
4 types of septation
atrioventricular septation
ventricular septation
atrial septation
septation of outflow
atrioventricular septation divides what
atria & ventricles
ventricular septation divides what
L & R ventricles
atrial septation divides what
L & R atria
septation of outflow divides what
aorta & pulmonary trunk
atrioventricular (AV) septation mechanism
endocardial cushions grow from walls of future atrioventricular junction
->
dorsal & ventral cushions fuse
->
forms 2 atrioventricular canals
(& forms AV septum that will grow down during ventricular septation)
what can go wrong with atrioventricular septation
Ebstein’s anomaly
cushions develop too inferiorly = enlarged R atrium
ventricular septation mechanism
ventricular septum grows from caudal to cranial
->
divides heart into 2 ventricles
muscular septum grows up from bottom almost to AV septum
->
AV septum grows down rest of way to meet it
what can go wrong with ventricular septation
VSD (ventricular septal defect)
a hole in the septum- named for location of hole
atrial septation mechanism
septum primum grows down from top
->
septum secundum (stronger/thicker) also grows down to the right of septum primum
->
foramen primum forms as septum primum nears AV septum
->
foramen secundum forms as foramen primum closes
->
septum secundum has a hole called foramen ovale
what is foramen ovale
hole formed in septum secundum
a one-way valve (bc fetal heart has higher BP on R side vs L side of heart)
what can go wrong with atrial septation
if foramen secundum & foramen ovale overlap =
patent foramen ovale
(leaves open hole between L + R atria)
pharyngeal arch arterial development (1-6)
1- maxillary a
2- stapedial a
3- internal and common carotid a
4- aortic arch and subclavian a
5- nothing
6- pulmonary trunk and ductus arteriosus
is blood in the fetus oxygenated or deoxygenated?
both, it’s a gradient
what is Tetralogy of Fallot
the outflow of the R ventricle is obstructed = reduced blood flow from the heart to the lungs
4 changes seen in the heart with Tetralogy of Fallot
aorta takes over & collects blood from both ventricles instead of just L
pulmonary valve stenosis
VSD (ventricular septal defect)
thickened R ventricle (hypertrophy- bc R side of heart has to work much harder)
