7/16 Flashcards
how do you calculate RBF and RPF
RBF = (PAH clearance) / (1-Hct)
RPF = (PAH clearance)
PAH clearance = [(urine PAH) x (urine flow)] / (plasma PAH)
how does the lecithin-sphingomyelin L/S ratio change in a developing baby
they’re ~the same until about 30 weeks, then L starts increasing while sphingomyelin stays roughly the same.
This increases the L/S ratio
how is glucose taken into the cells
facilitated diffusion via carrier-mediated transport
the GLUT carrier proteins are stereoselective for D-glucose
what is ferritin
an intracellular iron-binding storage protein
useful serum marker of total body iron stores
decreased in iron-deficiency anemia
elevated in iron-overload or infection
what is transferrin
molecule that delivers iron to liver and bone marrow
measure of iron in blood
for every 3 transferrin molecules, 1 will be bound to Fe.
what is TIBC and % saturation
TIBC:
measure of transferrin molecules in the blood
% saturation:
percentage of transferrin molecules that are bound by iron (normal is 33%)
what happens to Iron lab values when you have low iron
Low ferritin
(storage of Fe is depleated)
high TIBC
(always opposite of Ferritin)
low serum Fe
low % saturation
high Transferrin (when there’s low Ferrying, the liver will make more TF to try to increase Fe, and that’s also where the high TIBC comes from)
where is the majority of water reabsorbed in a nephron
proximal convoluted tubule
what is the thin descending loop known as
concentrating segment
passively reabsorbs water.
impermeable to Na+
what happens in the thick ascending loop
Na/K/2Cl transporter to reabsorb some of these ions.
urine becomes less concentrated as it ascends
impermeable to water, so it stays in the tubules.
what happens in the early Proximal convoluted tubule
reabsorbs >60% water filtered by glomerulus, regardless of hydration status
reabsorbs all glucose and amino acids
reabsorbs most small ions and uric acid
isotonic absorpption
what happens in the early distal convoluted tubule
makes urine fully dilute by reabsorbing Na and Cl.
urine is at its lowest osmolality here
H2O is impermeable in the early portion. becomes variable later on with Vasopressin
what is Hepatitis B’s replication sequence
dsDNA –> (+)RNA template –> dsDNA
HBV replicates via reverse transcriptase, even though it is a DNA virus
it occasionally goes to a single strand mode
what is the only ssDNA virus
Parvovirus B19
what is the histologic progression of an ischemic stroke
12-48 hrs: Red neurons (eosinophils! and loos of Nissl substance!!)
1-3 days:
necrosis + neutrophils
3-7 days:
macrophage/microglia and myelin phagocytosis
1-2 weeks:
reactive gloss and vascular proliferation
(liquefactive necrosis)
> 2 weeks:
glial scar formation w/ astrocytes
Run through Aortic/Pharyngeal arch derivatives
1st:
maxillary artery
CN 5
“1st is maximal”
2nd:
stapedial artery and hypoid artery
CN 7
“Second = Stapedial”
3rd:
Common Carotid artery and proximal internal Carotid
CN 9
“C is 3rd letter”
4th: on left, aortic arch on right, proximal R subclavian artery CN 10 "4th arch = 4 limbs = systemic"
6th:
proximal pulmonary arteries and (L) ductus arteriosus
CN 10
“6ulmonary arch”
run through pharyngeal pouch derivatives
1st:
ears
2nd:
tonsils
3rd:
inferior parathyroid
thymus
4th:
superior parathyroid
parafollicular C cells of thyroid
what stimulates neutrophil migration to inflammation
Leukotriene B4
“Neutrophils arrive B4 others”
what does PGI2 do
PGI2 inhibits platelet aggregation and promotes vasodilation
“Platelet gathering Inhibitor”
what does complement do
they’re inflammatory anaphylotoxins that trigger histamine release from mast cells
what does interferon-gamma do
activates macrophages, increases MHC expression, and promotes Th1 cell differentiation
produced primarily by activated T cells and NK cells
what does Thromboxane A2 do
increases platelet aggregation and vasoconstriction
what are the 3 important chemotactic agents
LTB4
C5a
IL-8 (clean up on aisle 8)
what does hydroxyurea do
increases HbF synthesis
reserved for sickle cell pts with frequent pain crises
