Chapter 20 – Cardiovascular System – The Heart

Vocabulary flashcards based on key concepts from the cardiovascular system and functions of the heart.

Functions of the Heart

Generating blood pressure, routing blood, ensuring one-way blood flow, and regulating blood supply.

Pulmonary Circuit vs. Systemic Circuit

The distinction between the circuits that transport blood to and from the lungs and the rest of the body.

Coronary Circulation Interruptions

Decreased blood flow leading to chest pain, heart muscle death, and scar tissue.

Treating Coronary Circulation Problems

Methods include using catheters to push plaque and the use of stents.

Epicardium

The outer layer of the heart wall; a serous membrane.

Myocardium

The middle layer of the heart wall responsible for contractions.

Endocardium

The smooth inner surface of the heart chambers.

Heart Valves

Ensure unidirectional blood flow and prevent backflow.

SA Node

The pacemaker of the heart generating spontaneous action potentials.

Atrioventricular (AV) Node

Delays action potentials to ensure proper timing between atrial and ventricular contractions.

Cardiac Muscle vs. Skeletal Muscle

Cardiac muscle is self-excitable and primarily relies on aerobic respiration.

Intercalated Discs

Structures that connect cardiac muscle cells and allow ion passage.

Electrocardiograph (EKG/ECG)

Records electrical activity of the heart, including arrhythmias.

Cardiac Cycle

All events associated with blood flow during a complete heartbeat.

Action Potentials in Cardiac Muscle

Characterized by a plateau phase in the action potential of cardiac contractile fibers.

Mean Arterial Pressure (MAP)

The average pressure in a patient's arteries during one cardiac cycle.

Congestive Heart Failure

A condition in which the heart's pumping efficiency is inadequate to meet the body's needs.