The largest artery, it receives blood from the left ventricle and branches to all parts of the body
Aortic valve
The valve at the entrance to the aorta
Apex
The point of a cone-shaped structure (adjective; apical); the apex of the heart is formed by the left ventricle and is pointed toward the inferior and left
Artery
A vessel that carries blood away from the heart; all except the pulmonary and umbilical arteries carry oxygenated blood
Arteriole
A small vessel that carries blood from the arteries into the capillaries
Atrioventricular (AV) node
A small mass in the lower septum of the right atrium that passes impulses from the sinoatrial (SA) node toward the ventricles
Atrioventricular (AV) valve
A valve between the atrium and ventricle on the right and left sides of the heart; the right AV valve is the tricuspid valve; the left is the mitral valve
Atrium
An entrance chamber, one of the two upper receiving chambers of the heart
AV bundle
A band of fibers that transmits impulses from the atrioventricular (AV) node to the top of the interventricular septum; it divides into the right and left bundle branches, which descend along the two sides of the septum; the bundle of his
Blood pressure
The force exerted by blood against the wall of a vessel
Bundle branches
Branches of the AV bundle that divide to the right and left sides of the interventricular
Capillary
A microscopic blood vessel through which materials are exchanged between the blood and the tissues
Cardiovascular system
The part of the circulatory system that consists of the heart and the blood vessels
Depolarization
A change in electrical change from the resting state in nerves or muscles
Diastole
The relaxation phase of the heartbeat cycle
Electrocardiography
Study of the electrical activity of the heart as detected by electrodes (leads) placed on the surface of the body; also abbreviated EKG from the German electrocardiography
Endocardium
The thin membrane that lines the chambers of the heart and covers the valves
Epicardium
The thin outermost layer of the heart wall
Functional murmur
Any sound produced as the heart functions normally
Heart
The muscular organ with four chambers that contracts rhythimically to propel blood through vessels to all parts of the body
Heart rate
The number of times the heart contracts per minute; recorded as beats per minute (bpm)
Heart sounds
Sounds produced as the heart functions; the two loudest sounds are produced by alternate closing of the valves and are designated S1 and S2
Inferior vena cava
The large inferior vein that brings blood low in oxygen back to the right atrium of the heart from the lower body
Left AV valve
The valve between the left atrium and the left ventricle; the mitral valve or bicuspid valve
Mitral valve
The valve between the left atrium and the left ventricle; the left AV valve or bicuspid valve
Myocardium
The thick middle layer of the heart wall composed of cardiac muscle
Pericardium
The fibrous sac that surrounds the heart
Pulmonary artery
The vessel that carries blood from the right side of the heart to the lungs
Pulmonary circuit
The system of vessels that carries blood from the right side of the heart to the lungs to be oxygenated and then back to the left side of the heart
Pulmonary veins
The vessels that carry blood from the lungs to the left sides of the heart
Pulmonary valve
The valve at the entrance to the pulmonary artery
Pulse
The wave of increased pressure produced in the vessels each time the ventricles contract
Purkinje fibers
The terminal fibers of the cardia conducting systems; they carry impulses through the walls of the ventricles
Repolarization
A return of electrical charge to the resting state in nerves or muscles
Right AV valve
The valve between the right atrium and right ventricle; the tricuspid valve
Septum
A wall dividing two cavities, such as two chambers of the heart
Sinus rhythm
Normal heart rhythm
Sinoatrial (SA) node
A small mass in the upper part of the right atrium that initiates the impulses for each heartbeat; the pacemaker
Sphygmomanometer
An instrument for determining arterial blood pressure
Superior vena cava
The large superior vein that brings blood low in oxygen back to the right atrium from the upper body