Embryology Flashcards
fistula
surgically created passage between an artery and a vein
What is Preeclampsia
Hypertensive disorder that occurs later in pregnancy (after 20 wks) in women who’s BP has been normal.
associated with premature birth and slow fetal growth
When is the most sensitive time after conception for the development of the cardiovascular system?
3.5-6.5 weeks post-conception
time frame when the heart tubes fuses all the way to just after the aortic arches forming
What is the earliest gestational age a infant is expected to survive?
23-24 Weeks
24 weeks the lungs are slightly more than just buds.
Lungs are the last organ to develope
Name the parts of the Cardiac Tube
When does the heart tubes form and move to one another
~day 19
When is the primitive heart tube formed?
What starts to happen?
day 22
blood begins to circulate and the heart begins to beat
Umbilical veins return
returns oxygenated blood from the placenta to fetus
vitelline veins return blood
carry blood from the yolk sac to the developing embryo supplying it with nurishments
Cardinal veins return blood
Collect deoxygenated blood from the fetus and deliver it to the heart
venous system, eventually turn into the SVC and IVC
Right Cardinal veins eventually become the
SVC
Right Vitelline veins eventually become
IVC
Left horn of the sinus venosus forms the
coronary sinus
All three left sinus venosus veins fuse to form coronary sinus
Endocardial cushion developes at day
32
forming right and left AVcanal
“dog bone”
IAS is formed at day
33
What happens at the 6th week?
6 paired aortic arches
~day 42
What does the third aortic arch form?
common carotid and proximal internal carotid artery
What does the fourth paired aortic arches form?
left and right pairs?
left 4th arch becomes the aortic arch
right 4th arch becomes the right subclavian
What does the sixth paired aortic arches form?
left becomes the left pulmonary artery
right becomes the right pulmonary artery
What week is the IVS formed?
7th week
By the ___ week, septation occurs and the truncus arteriosus, and bulbus cordis divide to complete formation of the outflow tracts
8th week
Normal embryology looping is
-during what week does this occur
D-looping- anterior & rightward RV
4th week
“Dextro” rightward looping
“S” shape
L-Looping is
ventricle inversion
primum septum begins to form around
day 25-28
when the cardiac looping begins
The sinus venosus of the heart tube will form the
common cardinal
vitellius
umbilical veins
Eventually will become part of the RA wall and develope into the coronary sinus and form the IVC and SVC
The primitive atrium of the heart tube will form the
right and left atria
The primitive ventricle of the heart tube will form the
left ventricle
The bulbus cordis of the heart tube will form
right ventricle
smooth portion of the conus, RVOT
LVOT
The truncus arteriosus of the heart tube will form into the
aortic and pulmonary trunks
Fusion of the Endocardial cusion divides the common atrioventricle opening into
right (tricuspid) and left (mitral) atrioventricular canals, seperating primative atrium and ventricle
the outflow tract (bulbus cordis and truncus arteriosus) begins as a
single tube connecting the ventricles. Two spiral ridges within the tract form a aorticopulmonary septum then eventually creating the semilunar valves.
What week is the fetal heart and vascular formation complete?
8th week
Shunts in fetus are what direction
Right to left
How does oxygenated blood return to the heart in fetal life?
from the placenta via the umbillical vein throught the ductus venosus into the IVC
How does the fetal blood return back to the placenta where oxygenation occurs?
most of the blood in the DAO travels throught the umbillical arteries back to the placenta where oxygenation will occur. The rest of the blood will actually travel to the lower extremities
With the first breath what happens
Pulmonary vascular resistance decreases
Lungs inflate, pressures drop
Because saturations are lower in a fetus vs a infant, a fetus can
survive almost any complex congenital defect
In a normal 40 week gestation infant a PDA and PFO usuallly closes within
a few hours or couple days
PFO should be completely sealed and closed off by
6 months of life
What is the Cardiac crux
is where the atria and ventricles connect
The term concordant means
normal seqential relationship between the heart chambers, valves and great vessels
The term discordance means
abnormal seqential relationship between the heart chambers, valves and great vessels
Persistance pulmonary hypertension of a newborn (PPHN) is characterized by
right to left shunting h
hypoxia
decreased O2
metabolic acidosis
Skeletal system of the heart includes
fibro-annular valve rings
The right pulmonary artery sits directly above the
left atrium
Think about crab view
