B4-046 CV Embryology Flashcards
I think these cards make more sense if the first 20ish are done in order
happy studying :)
septation of the chambers
- septum primum grows toward endocardial cushions, narrowing
ostium primum
septation of the chambers
2) ostium secundum forms in […]
septum primum
septation of the chambers
3) septum secondum develops on right side of […]
septum primum
ostium secondum maintains R to L shunt
septation of the chambers
4) septum secundum expands and covers most of
ostium secundum
residual foramen is foramen ovale
septation of the chambers
5) remaining portion of septum primum forms one-way valve of
foramen ovale
septation of the chambers
6) septum primum closes against septum secundum sealing the […] after birth
foramen ovale
due to increased LA pressure and decreased RA pressure
what allows the foramen ovale to close shortly after birth?
increased LA pressure
decreased RA pressure
caused by failure of the septum primum and septum secundum to fuse after birth
patent foramen ovale
can lead to paradoxical emboli
venous emboli entering into arterial circulation
patent foramen ovale
ventricle formation
1) muscular interventricular septum forms, the opening is called [..]
interventricular foramen
ventricle formation
2) aorticopulmonary septum rotates and fuses with muscular ventricular septum to form
membranous interventricular septum
closes interventricular foramen
ventricle formation
3) growth of endocardial cushions separates atria from ventricles and contributes to […] and […]
2 thing
- atrial septation
- membranous portion of IV septum
most common congenital cardiac anomaly, usually occurs in membranous septum
ventricular septal defect
outflow tract formation
3 steps
- neural crest cell migration
- truncal and bulbar ridges spiral and fuse to form aorticopulmonary septum
- forms ascending aorta and pulmonary trunk
conotruncal abnormalities associated with failure of neural crest cells to migrate
3
- transposition of great arteries
- tetralogy of fallot
- persistent truncus arteriosus
what valves are derived from the endocardial cushions of the outflow tract?
2
aortic, pulmonary
what valves are derived from the fused endocardial cushions of the AV canal?
2
mitral, tricuspid
this embryonic structure gives rise to what adult structure?
truncus arteriosus
ascending aorta and pulmonary trunk
this embryonic structure gives rise to what adult structure?
bulbus cordis
smooth parts (outflow tract) of right and left ventricles
this embryonic structure gives rise to what adult structure?
primitive ventricles
trabeculated part of left and right ventricles
this embryonic structure gives rise to what adult structure?
primitive atrium
trabeculated part of left and right atria
this embryonic structure gives rise to what adult structure?
left horn of sinus venosus
coronary sinus
this embryonic structure gives rise to what adult structure?
right horn of sinus venosus
smooth part of right atrium
this embryonic structure gives rise to what adult structure?
endocardial cushion
3
- atrial septum
- membranous IV septum
- AV and semilunar valves
this embryonic structure gives rise to what adult structure?
right common cardinal vein and right anterior cardinal vein
SVC
this embryonic structure gives rise to what adult structure?
posterior cardinal, subcardinal, and supracardinal veins
IVC
this embryonic structure gives rise to what adult structure?
primitive pulmonary vein
smooth part of left atrium
fetal circulation
blood entering the fetus through the umbilical vein is conducted via […] into IVC
ductus venosus
bypasses hepatic circulation
fetal circulation
most of the highly oxygenated blood reaching the heart via the IVC is directed through the […] into the left atrium
foramen ovale
fetal circulation
deoxygenated blood from the SVC passes through the RA -> RV -> pulmonary artery -> […] -> descending aorta
ductus arteriosus
shunt due to high fetal pulmonary artery resistance
right to left shunt congenital diseases
3
- persistent ductus arteriosus
- transposition of great arteries
- tetralogy of fallot
- early cyanosis “blue babies”
- diagnosed prenatally or shortly after birth
- require urgent surgical treatment
right to left shunt defects
- truncus arteriosus fails to divide into pulmonary trunk and aorta
- due to failure of aorticopulmonary septum formation
persistent truncus arteriosus
due to failure of aorticopulmonary septum to spiral
transposition of great arteries
- due to anterosuperior displacement of the infundibular septum
- most common causes of early childhood cyanosis
tetralogy of fallot
left to right shunt defects
3
- ventricular septal defect
- atrial septal defect
- patent ductus arteriosus
- acyanotic at presentation
- cyanosis may occur years later
left to right shunt defects
the heart first starts beating on
day 22
week 4
what two changes occur in the heart/vessels at birth?
- septum primum pushes against the septum secundum (closing the foramen ovale)
- ductus arteriosus closes
blood in the [chamber] is highly oxygenated in the fetus
right atrium
neural crest cells contribute to what structures?
2
- conotruncal cushions
- membranous portion of the IV septum
connects the umbilical vein and inferior vena cava
ductus venosus
returns deoxygenated blood to the placenta
umbilical artery
[…] give rise to endothelial cells
angioblasts
what heart layer do the coronary arteries arise from
epicardium
inflow of early heart tube
sinus venosus
outflow of early heart tube
truncus arteriosus/aortic sac
the cardiogenic field is established in the splanchic mesoderm in response to what transcription factor?
NKX2.5
lower levels of retinoic acid near the cranial heart tube specify
outflow tract and ventricle segments
higher levels of retinoic acid near caudal heart tube specify
atrium and sinus venosus
abnormal levels of retinoic acid may lead to adverse effects on
3
- specification
- anterior-posterior patterning
- cardiac neural crest cell population
IV membranous septation is very closely linked to
outflow tract septation
aorticopulmonary septum
neural crest cells contribute to the […] cushions
conotruncal
and membranous portion of IV septum
- “boot shaped heart”
- decreased pulmonary vascular markings
tetralogy of fallot
right ventricular hypertrophy leads to broad upturned cardiac apex
tetralogy of fallot
boot shaped heart
what would you expect on EKG for tetralogy of fallot?
- tall R waves- RVH
- prominent P waves - RA englargement
- Right axis deviation
what would you expect on echo in tetralogy of fallot?
- VSD
- overriding aorta
- RVH
- maybe pulmonary stenosis
VSD is in the […] part of the IV septum
membranous
defining features of tetralogy of fallot
- pulmonary stenosis
- overriding aorta
- VSD
- RVH
maybe patent ductus arteriosus as well
in TOF, pulmonary stenosis causes a […] shunt
right to left
what can be given to keep the ductus arteriosus open?
prostaglandins
what things close the ductus arteriosus?
NSAIDs
Endomethacin
prostaglandin antagonists
if the ductus arteriosus is closed prenatally, blood is directed from the RV…
to the high resistance, fluid filled lungs
why does the knee to chest position help with hypoxia?
3
- increases systemic vascular resistance
- decreases R to L shunt
- pulmonary flow to lungs is increased
risk factors for TOF
- rubella
- alcohol use
- AMA
- family hx
- genetics
- idiopathic
Right to left shunt defects
3
- TOF
- transposition of great arteries
- patent truncus arteriosus
left to right shunt defects
3
- ASD
- VSD
- patent ductus arteriosus
obstruction defects
2
- coarctation of the aorta
- valvular stenosis or atresia
early cyanosis
right to left defects
acyanotic at presentation
left to right defects
can result in left to right shunt disorders when pulmonary resistance approaches systemic levels and the shunt switches to right-to-left
eisenmenger syndrome
ductus arteriosus closes after birth and eventually forms
ligamentum arteriosum
the final growth of the IV septum is linked to
final septation of the truncus arteriosus
extensions of the atrioventricular endocardial cushions form the
IV septum
during the partitioning of the embryonic atrium into the right and left atria, two septa form three openings. List the order in which the septa and openings form.
- foramen primum in the septa primum
- foramen secundum in the septum primum
- foramen ovale in the septum secundum
connects pulmonary trunk to the arch of the aorta
ductus arteriosus
connect right atrium to left atrium
foramen ovale
shunts a portion of left umbilical vein blood to the vena cave, bypassing portal circulation
ductus venosus
what two structures allow blood to bypass the lungs during fetal development?
foramen ovale
ductus arteriosus
extensions of the […] grow along the septum to close the foramen primum
endocardial cushions
partition the outflow tract
conotruncal ridges
4 defining features of TOF
Pulmonary artery stenosis
Right ventricular hypertrophy
Overriding aorta
VSD
PROVe
due to abnormal spiraling during the septation of the truncus arteriosus
TGA
results from failure of fushion of the atrial septum primum and secundum
patent foramen ovale
boot shaped heart and decreased pulmonary vascular marking on CXR
TOF
signal RVH and pulmonary atresia
will prevent the ductus arteriosus from closing and reestablish ductal patency if its already closed
prostaglandin E1
