Lec 11: Arterial Supply

Vocabulary flashcards covering the components of the cardiovascular system, vessel anatomy, pulmonary and systemic circuits, major arterial branches, and related vascular pathologies.

Cardiovascular system

A system composed of three main parts: a fluid (blood), a muscular pump (the heart), and a series of conduits (blood vessels).

Pulmonary trunk

A large vessel that carries blood from the right ventricle to the pulmonary circulation.

Aorta

The largest artery that carries blood from the left ventricle to the systemic circulation.

Capillaries

The smallest blood vessels and sites of exchange, characterized by small diameters and thin walls allowing chemicals and gases to diffuse.

Fenestrations

Tiny holes in the single layer of endothelial cells that form capillary walls, making them permeable to water, ions, and small molecules.

Blood–brain barrier

A highly selective barrier formed by brain capillaries which do not have fenestrations.

Resistance vessels

A term for arteries and arterioles because their resistance can vary based on the stretching and recoiling of elastin and collagen, and the action of smooth muscle cells.

Tunica intima

The innermost layer of a blood vessel wall, including an endothelial lining and a connective tissue layer.

Internal elastic membrane

A layer of elastic fibers located in the outer margin of the tunica intima in arteries.

Tunica media

The middle layer of a blood vessel wall containing concentric sheets of smooth muscle in loose connective tissue.

External elastic membrane

A structure within the tunica media that separates it from the tunica externa.

Tunica externa

The outer layer of a blood vessel wall containing a connective tissue sheath to anchor the vessel; it contains collagen and elastic fibers in arteries, and elastic fibers and smooth muscle cells in veins.

Vasa vasorum

Literally “vessels of vessels”; small arteries and veins located in the walls of large arteries and veins that supply the cells of the tunica media and tunica externa.

Lumen

The internal space of a blood vessel; typically small and round in a collapsed artery and large and flat in a vein.

Vasoconstriction

The contraction of arterial smooth muscle by the sympathetic division of the autonomic nervous system ($ANS$).

Vasodilatation

The relaxation of arterial smooth muscle, resulting in the enlargement of the lumen.

Pulmonary arteries

Vessels that carry deoxygenated blood from the pulmonary trunk to the lungs; they branch into arterioles and then capillary networks surrounding alveoli.

Pulmonary veins

Vessels that carry oxygenated blood from the lungs and empty into the left atrium.

Systemic circuit

The part of the circulatory system that supplies the entire body except for the pulmonary circuit, containing $84\%$ of the total blood volume.

Brachiocephalic trunk

One of the three major branches of the aortic arch that delivers blood to the head and neck.

External carotid artery

A branch of the common carotid artery that supplies blood to the structures of the neck, lower jaw, and face.

Internal carotid artery

A branch of the common carotid artery that enters the skull to deliver blood to the brain via the ophthalmic, anterior cerebral, and middle cerebral arteries.

Basilar artery

An artery formed by the fusion of the left and right vertebral arteries that branches to form the posterior cerebral arteries.

Cerebral arterial circle

A vascular structure that interconnects the internal carotid arteries and the basilar artery to prioritize blood flow to the brain.

Atherosclerosis/Arteriosclerosis

A condition described as the hardening of the arteries where damage to the endothelial lining leads to plaque formation involving cholesterol, smooth muscle cells, and calcium deposits.

Thrombus

A blood clot that may form if platelets stick to arterial plaque; a coronary thrombosis can lead to a myocardial infarction.

Embolus

A piece of a thrombus that can lodge in a blood vessel, causing an embolism; an embolism in the brain can result in a stroke.