Contraction of skeletal muscle helps propel blood towards the heart.

Activation of the SNS causes dilation of veins to help push blood towards the heart.

Venous valves prevent backflow of blood into the lower extremities, which makes it easier to push blood back to the heart.

Pressure changes during breathing/respiration help push blood towards the heart.

Peripheral resistance is directly proportional to blood flow.

Vasodilation causes an increase in peripheral resistance.

Activation of the sympathetic nervous system decreases peripheral resistance.

Peripheral resistance is increased due to blood vessel vasoconstriction.

decreased white blood cell count

increased hematocrit (RBC count)

decreased hematocrit (RBC count)

increased white blood cell count

When MAP decreases, which decreases stretch of the blood vessel, the vessel responds by reducing flow.

When MAP increases, which increases the stretch of the blood vessel, the vessel responds by constricting.

When MAP increases, which increases the stretch of the blood vessel, the vessel responds by dilating.

When MAP decreases, which decreases stretch of the blood vessel, the vessel responds by constricting.

heart rate

blood volume

blood vessel diameter

oxygen carrying capacity of the blood

blood viscosity

blood vessel diameter

total blood vessel length

An increase in cardiac muscle contractility causes an increase in mean arterial pressure due to increased stroke volume.

An increase in cardiac output causes a decrease in aortic blood pressure, due to an increased volume of blood being pumped into the aorta with each heartbeat.

A decrease in heart rate directly causes increased mean arterial pressure.

Systemic vasodilation increases mean arterial pressure, due to increased peripheral resistance.

skin

heart

skeletal muscles

brain

kidneys