Questions derived From bRS Phys Flashcards
At steady state, ECF and ICF osmolarity are?
The same
What happens in the infusion of Isotonic NaCl?
ECF volume increases (no change occurs in osmolarity and therefor no shift of water to ICF)
Plasma [protein and hematocrit] decreases
Arterial blood pressure increases
What changes occurs in diarrhea (loss of isotonic fluid)
ECF volume decreases (but no change occurs in the osmolarity, so water does not shift from ICF)
Plasma [protein and. Hematocrit] increase
Arterial blood pressure decreases
What occurs in excessive NaCl intake?
Osmolarity of ECF increases
Water shifts from ICF to ECF (causing ICF osmolarity to increase)
ECF volume increases and ICF volume decreases
Plasma [protein and hematocrit] decrease bc of the increase in ECF volume
What happens in sweating in a desert? (Hyperosmotic volume contraction)
ECF osmolarity increases (more water than salt lost in sweat)
ECF Volume decreases -> water shifts from ICF to ECF -> ICF osmolarity increases to equal ECF
ICF volume decreases
Plasma [protein] decreases (hematocrit concentration stays the same due to the loss of fluid from RBC’s)
What happens in Syndrome of inappropriate antidiuretic hormone? (Gain of water)
Osmolarity of ECF decreases
ECF volume increases, water shifts to cells, ICF osmolarity decreases, ICF volume increases
Plasma protein concentration decreases
(Hematocrit remains same bc water shifts into RBC’s)
What happens in adrenocortical insufficiency (loss of NaCL)
Aka hyposomotic volume contraction
Osmolarity of ECF decreases
Water shifts into cells, ecf volume dcreases, ICF osmolarity decreases, ICF volume increases
Plasma [protein] increaases
Hematocrit concentration increases
Arterial blood pressure decreases
Vasoconstriction of renal arterioles occurs due to ?
Activation of sympathetic nervous system
Angiotensin II
What causes vasodilation of renal arteries ?
Prostaglandins E2 and I2, bradykinin
Nitric Oxide
Dopamine
Autoregulation of renal blood flow is accomplished by ?
Changing renal vascular resistance
(Myogenic mechanism - stretch reflex)
(Tubuloglomerular feedback - macula densa senses increased load and causes constriction in nearby afferent arteriole)
RBF is constant over a blood pressure range of ?
80-200mmHg
What happens to BUN and creatinine when GFR decreases?
They both increases
In prerenal azotemia (hypovolemia) BUN increases ____ than serum creatinine and there is a _______ BUN/creatinine ratio
More
Increased
Normal filtration fraction ?
0.20
FF = GFR/RPF
Increases in filtration fraction leads to ?
Increased protein concentration of peritubular capillaries and increased reabsorption in the proximal tubule
Decrease in filtration fraction leads to ?
Decreases in concentration of protein in the peritubluar capillaries and a decrease in reabsorption in the proximal tubule
The glomerular barrier consists of ?
The cappillary endothelium
Basement membrane
Filtration slits of the podocytes
What causes increases in Bowmans space hydrostatic pressure?
Constriction of the ureters
Increases in glomerular capillary protein concentration cause ______ in net ultrafiltration pressure and GFR
Decreases
______ in the proximal tubule reabsorbs glucose from tubular fluid into the blood
Na-Glucose cotransport
RPF is measured by the clearance of PAAH at plasma concentrations of PAH that are ______ than at Tm
Lower
Parathyroid hormone causes ______ and increased urinary ______
Phosphaturia
.cAMP
The ______ and _____ reabsorb more than 90% of the filtered calcium by passive processes that are coupled to Na reabsorption
Proximal tubule and thick ascending limb
_____ % of plasma calcium is filtered
60
Loop diuretics (Furosemide) cause ____ urinary calcium excretion
Increased
[urinary calcium is linked to Na reabsorption in the loop of henle. Inhibiting Na reabsorption therefore also inhibits Ca reabsorption]
The _________ and _________ reabsorb 8% of the filtered calcium by an active process
Distal tubule and collecting duct