FlashKeepers

Physiology · USMLE Step 1

USMLE Physiology High-Yield Rapid Review

A condensed rapid review pass over the highest yield physiology mechanisms and equations for final week review.

40 cards · basic cards · AI-written, checked twice. Edit anything.

Study this set free Look inside first Get FlashKeepers for iPhone
What is the formula for cardiac output?
CO = stroke volume x heart rate
What is preload?
The ventricular wall tension (stretch) at the end of diastole, approximated by end-diastolic volume
What is afterload?
The resistance the ventricle must overcome to eject blood, approximated by arterial pressure
According to the Frank-Starling law, increased venous return increases ____ by increasing myocardial stretch.
stroke volume
What is the formula for mean arterial pressure (MAP)?
MAP = diastolic pressure + 1/3(systolic pressure - diastolic pressure)
What is the formula for ejection fraction?
EF = stroke volume / end-diastolic volume
What effect does vagal (parasympathetic) stimulation have on the SA node?
Decreases heart rate by hyperpolarizing SA node cells and slowing phase 4 depolarization
SA node
The pacemaker of the heart, located in the right atrium
In capillary filtration, what does an increase in capillary hydrostatic pressure do to net filtration?
Increases net filtration out of the capillary
What is the baroreceptor reflex response to a sudden drop in blood pressure?
Decreased baroreceptor firing triggers increased sympathetic outflow, raising heart rate and vascular resistance
A rightward shift of the oxygen-hemoglobin dissociation curve is caused partly by increased ____.
2,3-DPG
What does a rightward shift of the oxygen-hemoglobin dissociation curve do to hemoglobin's oxygen affinity?
Decreases hemoglobin's affinity for oxygen, favoring unloading to tissues
What is the Bohr effect?
Increased CO2 and decreased pH shift the oxygen-hemoglobin curve right, promoting oxygen unloading in tissues
How does the V/Q ratio compare between the apex and base of the lung in an upright person?
The apex has a higher V/Q ratio than the base
What is physiologic dead space?
The sum of anatomic dead space plus alveolar dead space (ventilated but not perfused alveoli)

25 more cards in the app