Blood Vessels Structure and Function (Part A)

These flashcards cover key terms and concepts related to the structure and function of blood vessels in the cardiovascular system.

Arteries

Blood vessels that carry blood away from the heart, typically oxygenated except in pulmonary circulation.

Veins

Blood vessels that carry blood toward the heart, generally deoxygenated except for pulmonary circulation.

Capillaries

Microscopic vessels that allow for exchange of gases, nutrients, and wastes between blood and surrounding tissues.

Tunica intima

Innermost layer of a blood vessel wall in contact with blood, consisting of endothelium.

Tunica media

Middle layer of blood vessel walls made up mostly of smooth muscle and elastin, responsible for vasoconstriction and vasodilation.

Tunica externa

Outermost layer of blood vessel wall, composed mainly of connective tissue that anchors the vessel.

Elastic arteries

Thick-walled arteries with large lumens that conduct blood from the heart to medium-sized vessels.

Muscular arteries

Arteries that distribute blood to body organs and have thicker tunica media with more smooth muscle.

Arterioles

Smallest of arteries that lead to capillaries, control flow via vasodilation and vasoconstriction.

Capillary beds

Interwoven networks of capillaries between arterioles and venules where exchange of materials occurs.

Continuous capillaries

Least permeable capillaries with tightly joined endothelial cells; found in skin and muscle.

Fenestrated capillaries

Capillaries with Swiss cheese-like pores that allow for increased permeability; found in kidneys and intestines.

Sinusoidal capillaries

Highly permeable capillaries with large intercellular clefts; found in liver and spleen.

Vasa vasorum

Small blood vessels that supply blood to the outer layers of larger vessels.

Capacitance vessels

Veins that function as blood reservoirs, containing up to 65% of blood volume.

Venous valves

Structures in veins that prevent backflow of blood, particularly abundant in limb veins.

Anastomoses

Interconnections between blood vessels providing alternate pathways for blood flow.