The Circulatory System: Blood Vessels and Circulation

This set of flashcards consists of key terms and definitions related to the circulatory system, focusing on blood vessels and circulation as covered in the lecture notes.

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 arteries and veins allowing for exchange between blood and tissues.

Tunica intima

The innermost layer of blood vessel walls.

Tunica media

The middle layer of blood vessel walls, primarily made of smooth muscle.

Tunica externa

The outer layer of blood vessel walls, providing structural support.

Vaso vasorum

Small blood vessels that supply blood to the walls of larger blood vessels.

Conducting arteries

Large arteries that expand during systole and recoil during diastole.

Distributing arteries

Medium-sized arteries that distribute blood to specific organs.

Resistance arteries

Small arteries, including arterioles, that control blood flow to tissues.

Aneurysm

A bulge in an arterial wall due to weakness, often caused by high blood pressure.

Baroreceptors

Sensors in arteries that detect changes in blood pressure.

Chemoreceptors

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

Continuous capillaries

Type of capillaries with tight junctions and small gaps for minimal permeability.

Fenestrated capillaries

Type of capillaries with pores for greater permeability, found in organs requiring rapid exchange.

Sinusoids

Capillaries with wide gaps allowing large molecules and blood cells to pass, found in organs like the liver.

Precapillary sphincters

Muscles that regulate blood flow into capillary beds.

Hypotension

Abnormally low blood pressure.

Hypertension

Abnormally high blood pressure.

Vasomotion

The collective term for the constriction and dilation of blood vessels.

Reactive hyperemia

Increased blood flow following a period of restricted blood supply.

Angiogenesis

The growth of new blood vessels from pre-existing vessels.

Portal system

A vascular system that involves blood passing through two capillary beds before returning to the heart.

Hydrostatic pressure

The pressure exerted by a fluid at rest due to the force of gravity.

Osmotic pressure

The pressure needed to prevent the flow of water across a semipermeable membrane due to solute concentration.

Edema

Swelling caused by excess fluid accumulation in tissues.

Air embolism

The presence of air bubbles in the bloodstream, which can block blood flow.

Transient ischemic attacks (TIAs)

Brief episodes of reduced blood flow to the brain, often warning of an impending stroke.

Cerebral vascular accident (CVA)

Also known as a stroke, it is the sudden death of brain tissue due to ischemia.

Hepatic portal system

A system of veins that collects blood from the digestive organs and directs it to the liver.

Ascites

Abnormal accumulation of fluid in the peritoneal cavity.

Circulatory shock

A state where the heart's output is insufficient to meet the body's metabolic needs.

Neural control of blood pressure

Regulation of blood vessel diameter by the autonomic nervous system.