Changes in the activity of ______ fibers that innervate these vessels cause them to constrict or relax as needed to maintain blood pressure.

The venous system (veins) is a hige-pressure system that returns blood to the heart.

The _____ collect blood from the capillaries,

veins transport blood back to the ==➔________Vena Cava

the pressure in the left atrium is called the central venous pressure.

————anything that moves through the blood vessels until it reaches a vessel that is too small to let it pass. When this happens, the blood flow is stopped by the embolus.

An embolus is often a _____ piece of a blood clot that breaks off (thromboembolus)

Is a restriction in blood supply to tissues, causing a shortage of oxygen

It also means local anaemia

Ischemia comprises only insufficiency of oxygen,

Ischemia can be partial (poor perfusion) or total.

• Is tissue death

White infarctions (anemic infarcts)سؤال مهم

Red infarctions (haemorrhagic infarcts)
Generally affect the lungs or other loose organs ( ovary, small intestines)

Infarction of limb results in avascular necrosis.
.

The ability of tissues to increase blood flow in situations of increased activity, such as exercise, is called
مهم

When the blood supply to an area has been occluded and then restored, local blood flow through the tissues increases within seconds to restore the metabolic equilibrium of the tissues. This increased flow is called reactive hyperemia.

hyperemia cannot occur when the arteries that supply the capillary beds are narrowed.

dilated and tortuous veins that result from a sustained increase in pressure and allowing for reflux of blood and vein engorgement

Thrombophlebitis refers to thrombus formation in a vein