Blood Vessels and Circulation

A comprehensive set of vocabulary flashcards related to blood vessels and circulation, focusing on anatomy, physiology, and pathophysiology.

Tunica interna (intima)

The smooth inner layer of blood vessels that repels blood cells and platelets, composed of simple squamous endothelium.

Tunica media

The middle layer of a blood vessel, usually the thickest, consisting of smooth muscle, collagen, and elastic fibers.

Tunica externa (adventitia)

The outermost layer of a blood vessel made of loose connective tissue which includes vasa vasorum.

Arteries

Blood vessels that carry blood away from the heart.

Veins

Blood vessels that carry blood back to the heart.

Capillaries

Small blood vessels that connect arterioles to veins.

Blood pressure

The force that blood exerts against a vessel wall.

Systolic pressure

Blood pressure during ventricular systole.

Diastolic pressure

Blood pressure during ventricular diastole.

Pulse pressure

The difference between systolic and diastolic pressures.

Mean arterial pressure (MAP)

The average arterial pressure during a single cardiac cycle, estimated as diastolic pressure + (1/3 of pulse pressure).

Hydrostatic pressure

The physical force exerted against a surface by a liquid; it drives fluid out of capillaries.

Osmotic pressure

The pressure exerted by proteins in the blood that draws fluid into the capillaries.

Edema

Swelling caused by excess fluid in tissue spaces.

Vasomotion

The change in vessel radius through vasoconstriction or vasodilation.

Arteriovenous shunt

A direct connection between an artery and a vein, bypassing capillaries.

Precapillary sphincters

Muscle cells that regulate blood flow into capillary beds.

Chemoreceptors

Sensors that monitor changes in blood chemistry such as pH, oxygen, and carbon dioxide levels.

Baroreceptors

Sensory receptors that detect changes in blood pressure.

Angiotensin II

A potent vasoconstrictor and regulator of blood pressure.

Aldosterone

A hormone that promotes sodium and water retention, increasing blood volume and pressure.

Sympathetic control

Autonomic nervous system control that stimulates vasoconstriction in most blood vessels.

Circulatory shock

Any state where cardiac output is insufficient to meet metabolic needs.

Transcytosis

The process of transport vesicles across endothelial cells, important for the movement of certain substances.

Fenestrated capillaries

Capillaries with pores that allow for rapid absorption or filtration, found in organs such as the kidneys.

Continuous capillaries

Capillaries found in most tissues where endothelial cells have tight junctions.

Sinusoids

Irregular blood-filled spaces in tissues like the liver and spleen that allow for the passage of larger molecules and cells.