Cardiovascular System and Circulation

Circulatory System Transport

The system responsible for carrying oxygen, nutrients, hormones, and waste products throughout the body.

Pericardium

The closed outer sac that surrounds and contains the heart.

Oxygenated Blood

Blood that has been filled with oxygen from the lungs.

Deoxygenated Blood

Blood that has had most of its oxygen removed by tissues and is returning to the lungs ready to become reoxygenated.

Pulmonary Circulation

The circulatory route that transports deoxygenated blood from the heart through the lungs to be oxygenated before returning it to the heart.

Systemic Circulation

The circulatory route that delivers oxygenated blood from the heart to the rest of the body tissues and returns deoxygenated blood back to the heart.

Arteries

The largest blood vessels that carry blood away from the heart, possessing thick walls with smooth muscle that can constrict or dilate to regulate blood flow.

Arterioles

Smaller-diameter arterial vessels that branch from arteries and reside directly within the organs they supply with blood.

Veins

Large, thin-walled blood vessels that carry blood towards the heart and contain internal valves to prevent the backflow of blood.

Venules

Smaller-diameter venous vessels that form as veins divide and branch within tissues.

Venous Valves Distribution

Structures that are abundant in the veins of animal limbs to prevent backflow, but are quite sparse in the veins of internal organs.

Capillaries

Microscopic blood vessels within tissues that are only one cell thick and facilitate oxygen exchange.

Functions of Blood

Carrying oxygen and carbon dioxide, supplying water, transporting waste to the kidneys, regulating temperature by distributing heat, arresting haemorrhage via clotting, transporting hormones/enzymes, and providing immune defense.

Mediastinum

The region within the thorax, situated between the lungs, in which the heart is located.

Apex of the Heart

The pointed lower tip of the heart that points downwards and lies toward the left side of the thorax.

Atrium

A thinner-walled receiving chamber of the heart that contracts to force blood through an atrioventricular valve into a ventricle.

Ventricle

A thicker-walled pumping chamber of the heart that contracts to push blood out through a valve and into systemic or pulmonary circulation.

Tricuspid Valve

The right atrioventricular valve located between the right atrium and right ventricle, consisting of $3$ cusps or flaps.

Bicuspid Valve (Mitral Valve)

The left atrioventricular valve located between the left atrium and left ventricle, consisting of $2$ cusps or flaps.

Aortic Valve

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