Heart Vocab

Aorta

the main artery of circulatory system that carries blood from the left side of the heart to the arteries of all limbs and organs except the lungs.

Arteriole

a small terminal branch of an artery that connects with a capillary

Artery

\n a vessel that carries blood away from the heart to organs through the body.

Atrium (plural atria)

a chamber that receives blood returning to the heart.

Blood pressure

the hydrostatic force that blood exerts against the wall of a blood vessel.

Cardiac output

the volume of blood pumped per minute by the left ventricle of the heart.

Diastolic pressure

the minimum blood pressure during relaxation of heart muscles.

Elastic fibres

a thick, yellow connective-tissue fibre composed principally of elastin and characterized by giving great elasticity to tissues in the body.

Epinephrine

a hormone produced as a response to stress, also called adrenaline.

Medulla

the lowest part of the brain that controls autonomic and homeostatic functions.

Myogenic contraction

a contraction of the heart without external stimulation from a nerve.

Pacemaker

a specialized region of the right atrium that sets the rate of heart contraction, also called the sinoatrial (SA) node.

Pulmonary circulation

the separated circulatory system that links the lungs and heart in humans.

Pulse

the force of blood leaving the heart in one heartbeat; it is felt where arteries pass near the skin.

Systemic circulation

the separated circulatory system that links the heart to the rest of the body.

Systolic pressure

the maximum blood pressure caused by heart muscles contracting and pumping blood.

Valve

a membranous structure in a hollow organ or passage that folds or closes to prevent the return flow of the body fluid passing through it.

Vasoconstriction

when the circular muscles in the artery wall contract, narrowing the lumen.

Vasodilation

when the circular muscles relax, increasing the lumen size and hence blood flow to downstream tissues.

Vein

a vessel that returns blood to the heart.

Ventricles

the chambers on the left and right side of the heart that receive blood from the atria and contract to force it into the aorta and pulmonary artery respectively.

Capillary

a microscopic blood vessel that penetrates the tissues and consists of a single layer of endothelial cells to allow exchange with interstitial fluid.