Systole (254)

Contraction of the heart chambers which results in the emptying of the atria or ventricles with blood.

coronary artery

(249)

Artery that supplies blood to the muscular wall of the heart.

interatrial septum

(248)

Wall between the atria of the heart.

interventricular septum (248)

Wall between the ventricles of the heart.

myocardium (248)

Heart (cardiac) muscle consisting of striated muscle cells that interlock.

pulmonary circuit (247)

Path of blood through vessels that take O₂ poor blood to and O₂ rich blood away from the lungs.

tricuspid valve (248)

AtrioVentricular (AV) valve which separates the right atrium and right ventricle and prevents the back-flow of blood from the right ventricle into the right atrium.

sinatrial (SA) node (251) 

Small region of neuromuscular tissue that initiates the heartbeat; also called the pacemaker.

Purkinje fibers (251)

Specialized muscle fiber that conducts the cardiac impulse from the AV bundle into the ventricular walls.

atrioventricular (AV)

valve (248)

Valve located between an atrium and ventricle; includes the bicuspid (left) & tricuspid (right) valves.

atrioventricular node (251)

Small region of neuromuscular tissue located near the septum of the heart that transmits impulses from the SA node to the ventricular walls.

atrium (248)

Upper chambers of the heart that receive blood from veins.

bicuspid valve

(248)

Atrioventricular valve located between the left ventricle and left atrium.  A.K.A. mitral valve.

cardioregulatory center

(256)

Portion of the medulla oblongata that regulates the heart rate.

chordae tendinae

(248)

Tough bands of connective tissue that attach the papillary muscle to the av-valves of the heart.

diastole (254)

Relaxation of the heart chambers which results in the filling of the atria or ventricles with blood.

endocardium (248)

Thin inner wall of the heart; exposed to the blood.

papillary muscle (248)

Muscle that extends inward from the ventricular walls of the heart & to which the chordae tendinae attach.

systemic circuit

(247)

Part of the cardiovascular system that serves body parts other than the gas-exchanging surfaces in the lungs.

semilunar valve (248)

Valves resembling a half-moon located between the ventricles and their attached blood vessels (arteries).

arteriole (257)

Branch from an artery that leads to a capillary.

artery (257)

Blood vessels consisting of 3 tunics in which blood always flows away from the heart.

capillary (257)

Microscopic vessel located in the tissues connecting arterioles to venules; molecules either exit or enter the blood through the thin walls.

tunica externa (257)

An outer connective tissue layer in an artery composed of primarily elastic and collagen fibers.

tunica media (257)

A thick middle layer in an artery composed of smooth muscle and elastic fibers.

tunica interna(257)

An inner layer composed of endothelium with a basement membrane.

vein (258)

Blood vessel that carries blood to the heart.

venule (258)

Type of blood vessels that takes blood from capillaries to veins.