The Cardiovascular System: Blood Vessels

These flashcards cover essential vocabulary related to the structure and function of blood vessels, including types of vessels, blood pressure regulation, and key physiological concepts.

Blood vessels

Delivery system of dynamic structures that begins and ends at the heart, working with the lymphatic system to circulate fluids.

Arteries

Blood vessels that carry blood away from the heart; oxygenated in the systemic circuit but deoxygenated in the pulmonary circuit.

Capillaries

The smallest blood vessels that provide direct contact with tissue cells, directly serving cellular needs.

Veins

Blood vessels that carry blood toward the heart; deoxygenated in the systemic circuit and oxygenated in the pulmonary circuit.

Tunica intima

The innermost layer of blood vessels that is in intimate contact with blood and consists of endothelium and a subendothelial layer.

Tunica media

The bulky middle layer of blood vessels, mostly composed of smooth muscle and sheets of elastin, responsible for controlling blood flow and pressure.

Tunica externa

The outermost layer of blood vessels, primarily made up of loose collagen fibers that protect and reinforce the walls.

Arterioles

The smallest of all arteries that control blood flow into capillary beds through vasodilation and vasoconstriction.

Continuous capillaries

Capillaries with abundant tight junctions, minimal intercellular clefts, found in skin, muscles, lungs, and CNS.

Fenestrated capillaries

Capillaries that have Swiss cheese-like pores (fenestrations) that increase permeability, found in kidneys and intestines.

Sinusoidal capillaries

Highly permeable capillaries with large intercellular clefts and incomplete basement membranes found in liver and spleen.

Capillary beds

Interwoven networks of capillaries between arterioles and venules involved in blood exchange.

Vasomotor nerve fibers

Sympathetic nerves that control the diameter of blood vessels through vasoconstriction and vasodilation.

Venous valves

Valves in veins that prevent backflow of blood, abundant in limbs.

Cuff method

A method used to measure blood pressure indirectly with a sphygmomanometer by detecting sounds of Korotkoff.

Systolic pressure

The pressure exerted in the aorta during ventricular contraction, averaged at 120 mm Hg in normal adults.

Diastolic pressure

The aortic pressure when the heart is at rest.

Mean Arterial Pressure (MAP)

The average pressure that propels blood to tissues, calculated using diastolic pressure and pulse pressure.

Renin-Angiotensin-Aldosterone System

A hormone system that regulates blood pressure by altering blood volume and peripheral resistance.

Vasa vasorum

A system of tiny blood vessels that supply blood to larger vessels.

Peripheral resistance

Opposition to blood flow due to friction as blood encounters vessel walls, influenced by vessel diameter and other factors.