Week 1: Friday Flashcards
why would the fetus die without a patent foramen ovale
the heart would not recieve sufficient blood because it would go to the non-functioning lungs and therefore the fetus would not recieve proper nutrients and oxygenated blood - die bc cant breathe or not getting enough oxygenated blood
what makes the foramen ovale close at birth
When a baby’s lungs begin working, blood flow through the heart changes. Now the oxygen-rich blood comes from the lungs and enters the left atrium. At this point, blood flow follows the normal route. The pressure of the blood pumping through the heart usually forces the flap opening of the foramen ovale to close
if the ventricular septum does not close completely (ventricular septal defect), a shunt will occur between the ventricles. Which way would the blood tend to flow across this shunt after birth? What organ would become overloaded with blood?
- right side of heart to go across VSD and into aorta
- dilution of aortic blood with low oxygen blood from right heart = cyanosis
- aorta gets overloaded with blood
which way does blood flow through the primitive tube
primitive artium - primative ventricle - bulbus cordis - truncus arteriosus
what will the structure truncus arteriosus form?
aortic arches and most cranial portion becomes the pulmonary arteries
what is the fetal ductus arteriosus
- blood vessel that connects the pulmonary artery to the aorta ( R to L flow)
- allows blood to bypass the lungs, which are not inflating or exchanging oxygen
what happens in the first week of life
ductus arteriosus
- inflation of lungs and increase in oxygen tension of blood causes smooth muscle in the ductus to constrict, closing the ductus
- if smooth muscle ring is not complete and ductus remains open - patent ductus arteriosus (PDA)
what is patent ductus arteriosus
blood flow moves from aorta to pulmonary artery (L to R) is high velocity and turbulent
what does the ductus arterisosum turn into in adults
ligamentum arteriosum
what are the clinical consequences of PDA
- continual high speed flow from the aorta through PDA into pulmonary artery
- continuous heart murmur
- increased blood flow within the blood vessels that form the PDA circuit
- overcirculation causes development of congestion in the tissue of the lungs: pulmonary edema
what are the clinical evaluations of PDA
- radiographs, angiography
- echocardiography
what is the treatment of PDA
- surgical ligation around the PDA at open chest surgery
- device occlusion of the PDA
what is the prognosis once PDA is occluded
good long-term
what is the valve that connects pulmonary artery and right ventricle
pulmonary valve
what is the valve that connects the aorta and left ventricle
aortic valve
how are the semilunar valves formed
- interior wall of embryonic vessels undergo remodeling and sculpting
- series of swellings that come out that form the primitive valve
- to form valve, cells around it regress/apoptosis
- left with fine, delicate structures
what is a common congenital malformation of semilunar valves
- failure of valve leaflets to fully separate
- fused leaflets, failure to open during ventricular contraction
what is valve stenosis
valve opening is narrowed
what does pulmonic valve stenosis cause
- increase in heart muscle mass
- decreased blood flow
- arrhythmias (abnormal heart rhythms)
- congestive heart failure
- exercise intolerance
- fainting
what is treatment of pulmonic stenosis
- go into jugular vein then cranial vena cava then RA then RV then pulmonic valve
- insert catheter that has deflated balloon and inflate balloon to open valve
what is ventricular septation
- ventricular septum divides the ventricle in left and right halves
- allows blood to flow in series with no mixture of unoxygenated and oxygenated blood
what does the bulbus cordis do
helps form the dorsal portion of the septum, continues into truncus arteriosus, which forms spiral structure of the aorta and pulmonary artery
where does the bulbus cordis need to line up
lines up with interventricular septum to place the pulmonary artery over the right ventricle and aorta over left ventricle
what is tetraology of fallot
4 defects resulting from failure of conotruncal septum to align with the ventricular septum
what are the 4 defects of TF
- failure of ventricular septum to fully close, VSD
- narrowed right-sided opening from RV leading to pulmonic valve stenosis
- rightward deviaition of the left sided opening from the lV leading to rightward positioning of aorta
- right heart enlargement secondary to pulmonic valve stenosis
what are the consequences of T of F
- allows blood from right side of heart to go across VSD and into aorta
- dilution of aortic blood with low oxygen blood from right heart - cyanosis
what is persistent right aortic arch (PRAA)
- right aortic arch persists and left aortic arch regresses
- PRAA and remnants of the left arch encircle and constrict the esophagus
what are the consequences of PRAA
megaesophagus and regurgitation
surgical correction of PRAA
cut left ligamentum
