Heart and Circulatory System

Flashcards to review key terms and concepts related to heart anatomy, physiology, and the circulatory system for exam preparation.

Pathway of Blood Through Heart

Describes the flow of blood from body to heart, to lungs, and back to the body.

Atria

The receiving chambers of the heart where blood enters.

Ventricles

The discharging chambers of the heart that pump blood out.

Heart Valves

Ensure unidirectional blood flow and prevent backflow in the heart.

Semilunar (SL) valves

Prevent backflow from major arteries back into ventricles.

Valvular stenosis

Condition where valve flaps are stiff and constrict the opening, requiring more heart force to pump blood.

Cardiac Output (CO)

Volume of blood pumped by each ventricle in one minute, calculated as CO = heart rate (HR) x stroke volume (SV).

Preload

Degree of stretch of heart muscle before contraction, influencing end-diastolic volume.

Contractility

Contractile strength of heart muscle at a given muscle length.

Afterload

Back pressure exerted by arterial blood that ventricles must overcome to eject blood.

Intrinsic Conduction System

Network of noncontractile cells that initiate and distribute impulses for coordinated heart beat.

Sinoatrial (SA) Node

The pacemaker of the heart that generates impulses.

Gap Junctions

Structures that allow electrical signals to pass rapidly between cardiac muscle cells.

Electrocardiogram (ECG or EKG)

Graphic recording of electrical activity of the heart.

Blood Pressure (BP)

Force exerted on blood vessel walls by blood per unit area.

Mean Arterial Pressure (MAP)

Average pressure in a person's arteries during one cardiac cycle.

Neural Control Mechanisms

Regulatory factors that alter resistance and blood distribution in response to demands.

Baroreceptors

Sensors located in arteries that detect changes in blood pressure.

Chemoreceptors

Sensors that detect changes in blood chemistry, such as CO2 and O2 levels.