Cardio Flashcards
most common embryologic heart defect
affects what portion of hear
IVS defect
membranous (25%)
what does foramen oval form
what is it’s function
fossa ovalis
shunts blood from left to right because lung aren’t functioning in neonate
what is the difference between adult and fetal hemaglobin
fetal: alpha2 gamma2 (gamma binds 02 more than beta)
adult: alpha2 beta2
when do sx of sickle cell anemia show up?
around 6 months when fetal hemoglobin is depleted
most likely symptom of persistent foramen oval?
if it doesn’t close may see cyanosis
what form of persistent truncus arteriosis is more compatible with life?
unequal divison
tetrology of fallot
- persistent truncus arteriosis (aorta takes over and pulmonic valve gets stenotic)
- right ventricular hypertrophy
- VSD
- pulmonary stenosis
fetal circulation
what does it bypass?
oxygenated blood from umbilical vein
bypasses the liver because mothers liver does the work
what shunt bypasses liver in fetal circulation?
ductus venosis/ligamentum venosum
what shunt shunts blood from pumonic artery to aorta to bypass the lungs?
ductus arteriosis/ligamentum artereosum
does placenta exchange blood?
No, not on a large scale
what does mother take from baby?
what does baby take from mother
give: metabolites that need to be removed as waste
take: o2 and nutrients, immunoglobulins (IgG), drugs, nicotine, alcohol, teratogens, listeria, etc.
what is a landmark for fetal heart development
week 4
4 chambers and a beating heart
stages of fetal erythropoesis where blood gets made
1: yolk sac (3 weeks - 8 weeks)
2: liver (6 weeks - )
3: spleen (9 weeks - 28 weeks)
4: bone marrow (takes over at 9 weeks)
what is main organ that produces blood in utero?
liver
cardiac output
CO = SV x HR
amount of blood out of heart during systole
what is associated with poor CO
cardiomyopathies
CHF
sympathetic
pupils dilate
lungs dilate
HR increases
parasympathetic
pupils constrict
lungs bronchoconstrict
HR decreases
AcH and vagus nerve communicate to heart to decrease rate
What determines conduction/HR
rate?
AV rate
bundle of HIS rate
SA node in top r atrium
70-90bpm
40-60
15-40
what communicates with SA node
with AV node?
R vagus
L vagus to slow
stroke volume
what is sv determined by?
normal ejection fraction
end diastolic minus end systolic
determined by: contractility, TPR, preload, SV, compliance
55-70%
what decreases HR?
beta blockers and Ca CH blockers
what does increased BP do to after load and SV?
increases after load and decreases SV
what organ gets the most blood?
what organ has the highest flow rate of blood?
liver
kidney
what makes heart muscle different than skeletal muscle?
- autorhymicity: myocytes at SA node, funny sodium channels (Naf), Ca.
- prolonged Ca channels: slow type Ca for slow prolonged contraction
- skeletal muscle can increase motor units to increase contraction but heart can’t increase numbers.
syncytium
pores so signal gets to all cells in heart simultaneously to contraction happens at the same time
what channel is unique to heart muscle
slow type ca channel
what allows SA/AV nodes to discharge
funny Na channels
capillaries grow due to
hypoxial/low oxygen state
types of capillaries
- continuous: single cell layer, no breaks, in BBB
- fenustrated: holes in capillaries, leaky, in kidney, intestines, pancreas
- discontinous/sinusoidal: lets a lot through, in liver, spleen, marrow
majority of blood is where?
in venous system (64%)
capilarries (20%)
oncotic pressure
hydrostatic pressure
moves things into capillaries
moves things out
