muscular artery

arteriole

vein

capillary

when ventricular pressure becomes greater than aortic pressure

when the semilunar valves open

when atrial pressure becomes greater than ventricular pressure

when ventricular pressure becomes greater than atrial pressure

when aortic pressure becomes greater than ventricular pressure

Increased preload of cardiac muscle cells due to increased venous return.

Increased sympathetic nervous system activation.

Increased afterload on the heart.

Increased contractility of the cardiac muscle.

T wave

QRS complex

P wave

It allows the atria to contract before the ventricles depolarize and contract.

It decreases the pressure generated in the right side of the heart.

It prevents heart murmurs (valve dysfunction).

It prevents the atria from contracting.

The semilunar valves are open.

The ventricles are in diastole.

Atrial pressure is less than ventricular pressure.

The AV valves are closed.

potassium movement out of the cardiac myocytes

calcium movement out of the cardiac myocytes

sodium movement into the cardiac myocytes

sodium movement out of the cardiac myocytes

potassium movement into the cardiac myocytes

calcium movement into the cardiac myocytes

decreasing end-systolic volume (ESV)

decreasing end-diastolic volume (EDV)

decreasing heart rate

decreasing stroke volume

Increased venous return increases EDV but decreases the preload of the heart.

Increased venous return decreases EDV but increases the preload of the heart.

Increased venous return increases both EDV and preload of the heart.

Increased venous return decreases both EDV and preload of the heart.

cardiogenic shock

hypovolemic shock

neurogenic shock

septic shock

anaphylactic shock