The Circulatory System: Blood Vessels and Circulation

This set of flashcards covers key concepts related to the circulatory system, focusing on blood vessels, blood pressure, and hemodynamics.

Arteries

Blood vessels that carry blood away from the heart, featuring thicker muscular walls to withstand higher pressures.

Veins

Blood vessels that return blood to the heart, characterized by larger diameters and thinner walls compared to arteries.

Capillaries

The smallest and most numerous blood vessels connecting arterioles to venules, facilitating exchange between blood and tissues.

Blood Pressure (BP)

The force exerted by circulating blood on the walls of blood vessels, measured in mm Hg.

Systolic pressure

The peak arterial blood pressure during ventricular contraction.

Diastolic pressure

The minimum arterial blood pressure during ventricular relaxation.

Pulse Pressure

The difference between systolic and diastolic pressures, indicative of the stress on arteries.

Mean Arterial Pressure (MAP)

The average pressure within the arteries during one complete cardiac cycle, calculated as diastolic pressure plus one-third of the pulse pressure.

Hypertension

Chronic high blood pressure, typically defined as resting BP greater than 130/80 mm Hg.

Aneurysm

A weak point in an artery or heart wall that bulges and can potentially rupture, commonly due to atherosclerosis and hypertension.

Atherosclerosis

A progressive disease characterized by the buildup of plaques in the arteries, which narrow the lumen and reduce blood flow.

Capillary Exchange

The two-way movement of materials, such as fluids and nutrients, across capillary walls, primarily through diffusion.

Edema

The accumulation of excess fluid in a tissue, usually caused by increased capillary filtration, reduced absorption, or obstructed lymphatic drainage.

Venous return

The flow of blood back to the heart through the veins, dependent on factors like pressure gradients and muscle contractions.

Vasomotion

The process of changing the diameter of blood vessels to regulate blood flow and pressure.

Autoregulation

The ability of tissues to regulate their own blood supply in response to local conditions.

Baroreceptors

Sensory structures in blood vessels that monitor blood pressure and send feedback to the brain for the regulation of heart rate and vessel diameter.

Renin-Angiotensin System (RAS)

A hormone system that regulates blood pressure and fluid balance, involving vasoconstriction and water retention mechanisms.

Thrombosis

The formation of a blood clot in a blood vessel, which can lead to blockage and tissue death if not resolved.