Diagnostics Flashcards
What would happen to resistance to flow if vessel diameter is decreased half its original value?
Resistance will increase 16-fold.
Closure of the semilunar valves happen in what phase of the cardiac cycle?
Isovolumetric relaxation
- Isovolumetric contraction: Closure AV valves
- Rapid ventricular ejection: opening SL valves
- Rapid ventricular filling: opening AV valves
Closure of the atriventricular valves happen in what phase of the cardiac cycle?
Isovolumetric contraction
- Isovolumetric relaxation: Closure SL valves
- Rapid ventricular ejection: opening SL valves
- Rapid ventricular filling: opening AV valves
In hypotensive patients with intact baroreceptor reflex, the following events takes place, except:
a. Firing rate of Hering nerve will decrease
b. Sympathetic activation predominate
c. HR will increase
d. SVR will increase
e. NOTA
e. NOTA
* Hering nerve is part of CN IX, so it is basically a parasympathetic nerve. In hypotension, sympathetic nerve should predominate, firing rate should decrease.
A patient has CO of 3.2L/min, with an EF of 55% and a HR of 100bpm. What is the EDV?
a. 52.80 mL
b. 58.18 mL
c. 60.08 mL
d. 72.80 mL
e. 88.34 mL
EDV= 58.18 mL
EF= 0.55 or SV/EDV SV= 0.55 x EDV
CO= SV x HR 3.2= (0.55 x EDV) x 100 EDV= (3.2/0.55) x 1000 EDV= 58.18 mL
Respiratory control center responsible for the basic rhythm of respiration.
Dorsal respiratory group (DRG)
- VRG: located in medulla; for active respiration
- DRG: located in medulla; for basic rhythm, inspiration
- Apneustic center: located in lower pons; prolong respiration, decreases RR
- Pneumotaxic center: located in upper pons; shortens inspiration, increases RR
Substance leads to vasodilation of renal vessels, except:
a. prostaglandins
b. angiotensin II
c. low dose dopamine
d. prostacyclin
e. bradykinin
b. Angiotensin II
* causes vasoconstriction of renal vessels
The following conditions decrease distal tubular K+ secretion, except:
a. low K+ diet
b. Spirinolactone
c. acidosis
d. hypoaldosteronism
e. Loop diuretics
e. Loop diuretics
* it increase urine flow rate, therefore, maintains the luminal concentration of K+ in the distal tubule. This results in concentration gradient that favors increase tubular secretion of K+ that leads to hypokalemia.
ACe inhibitors and ARB can decrease GFR by what mechanism?
Decrease in glomerular capillary hydrostatic pressue.
- efferent arteriole constriction
p50 of Hemoglobin is?
25 mmHg
Cholecystokinin leads to a decrease in?
gastric emptying
*thus increase in gastric emptying time–longer time for the food to stay in the stomach
A patient who has pituitary tumor compressing on optic chiasma would produce what visual field defect?
Bitemporal hemianopsia
- Optic nerve: unilateral blindness
- Optic tract, Geniculocalcarine tract: Contralateral homonymous hemianopsia
- Meyer’s loop: contralateral Superior homonymous quadrantinopsia
- Parietal lobe: Inferior left homonymous quadrantinopsia
A patient who has a lesion in Meyer’s loop of the temporal lobe on the right side will produce what visual field defect?
Meyer’s loop: Left Superior homonymous quadrantinopsia
- Optic nerve: unilateral blindness
- Optic tract, Geniculocalcarine tract: Contralateral homonymous hemianopsia
- Meyer’s loop: contralateral Superior homonymous quadrantinopsia
- Parietal lobe: Inferior left homonymous quadrantinopsia
- Optic chiasm: Bitemporal hemianopsia