questions given Flashcards
how do you calculate gain?
gain is the correction over the error. The correction seen in a uncontrolled to controlled system. error is the amount not seen corrected:
uncontrolled: pressure rise from 100 to 175
controlled: pressure rise from 100 to 125
the error is 25 because it’s how much from the “norm” that wasnt corrected. Corrected amount is 50. Gain is 50/25 = 2 (negative because negative feedback)
how do secondary transporters get their energy?
the energy is derived from concentration gradients created by atp driven primary active transport
what ions are normally concentrated in extracellular fluid?
Na+ and Ca++ and Cl-
what ions are normally concentrated in intracellular fluid?
K+
in a muscle contraction what does the diffusion of acetylcholine and binding to ligand-gated sodium channels cause?
a local or end-plate depolarization cause by sodium ion influx, but not the action potential. it opens voltage gated channels.
which band in a sarcomere doesnt change length during a contraction?
A Band
others: I band - narrows (outer edge), H band: also narrows (center)
Each of these utilize DHP channels on T-tubules during contraction
skeletal muscle fibers and cardiac muscle fibers
what phase of a cardiac muscle action potential represents resting potential?
Phase 0 Phase 1 Phase 2 Phase 3 Phase 4
Phase 4 - resting potential (-85 mV)
In cardiac contractions, what do the terms EDV, SV and ESV mean?
EDV - end diastolic volume
ESV - end systolic volume
SV - stroke volume - 70 ml (a difference of the others)
what does the P wave represent in an ECG? QRS? and the T wave?
P - atrial depolarization
QRS - ventricular depolarization
T - ventricular repolarization
how much of total volume is in the venous system alone?
64%
A systemic vein is 8x distensible and has a volume 3x as great than a artery. What’s it’s compliance in comparison?
3 x 8 = 24
a systemic vein has 24x the compliance of an artery.
whats the mean circulatory pressure when blood volume is 4 L?
0 mm Hg
7 mm Hg @ 5 L
on the normal venous return curve when Right atrial pressure is equal to mean systemic filling pressure the venous return is what?
0 L/min
whats our normal glomerular filtration rate?
125ml/min or 180 L/day
what factor in GFR has the most effect on increasing GFR?
Pg - glomerular hydrostatic pressure - 60 mm Hg
the proximal tubule which does a lot of reabsorption, reabsorbs filtered glucose and amino acids through ___________.
sodium/glucose transporter
where do you find aldosterone’s target on the principal cells or the cortical collecting ducts of the nephron? what is aldosterone’s target?
on the basolateral side of the principle cell, aldosterone acts on Na+/K+ pumps
intercalated cells on the late distal and cortical collecting tubule do what?
secrete H+ and reabsorb bicarbonate
the phosphate buffering system major role is what?
buffering renal tubule fluid (lowers tubule pH)
how does the body compensate for respiratory acidosis?
new bicarbonate from the kidney
how does the body compensate for metabolic acidosis?
increased ventilation rate
how is respiratory alkalosis compensated for?
renal excretion of bicarbonate
how is metabolic alkalosis compensated for?
decreased ventilation
