Heart Anatomy and Physiology (Page 1 Notes)

Vocabulary flashcards covering heart anatomy, physiology, and components from Page 1 notes.

Sarcoplasmic Reticulum

Stores and releases calcium ions for muscle contraction.

Calcium Ions

Bind to troponin to enable actin-myosin interaction and muscle contraction.

Troponin

Regulatory protein that binds calcium and, with tropomyosin, regulates muscle contraction.

Pacemaker Cells

Specialized cardiac cells that initiate and distribute electrical impulses for coordinated heartbeat.

Gap Junctions

Intercellular channels that allow communication and coordination between muscle cells.

Functional Syncytium

The heart’s muscle cells contract as a unit due to electrical coupling.

T-Tubules

Invaginations of the cell membrane that spread action potentials quickly into the muscle cell.

Striated

Muscle tissue with a striped appearance due to organized actin and myosin filaments.

Multinucleate

Muscle cells contain multiple nuclei to support protein synthesis and repair.

Pathway of Blood Through the Heart

Sequence: right atrium → right ventricle → pulmonary trunk → lungs → pulmonary veins → left atrium → left ventricle → aorta (includes coronary circulation).

Atria

Receiving chambers of the heart; receive blood from the body (right) and lungs (left).

Ventricles

Discharging chambers; right ventricle pumps to the lungs, left ventricle pumps to the body.

Pericardium

Double-walled sac surrounding the heart with three layers: fibrous pericardium, parietal serous pericardium, and epicardium.

Epicardium

Outer layer of the heart wall; visceral layer of serous pericardium.

Myocardium

Muscular middle layer of the heart wall that contracts to pump blood.

Endocardium

Inner lining of the heart chambers.

Atrioventricular (AV) Valves

Tricuspid and Mitral valves; prevent backflow into the atria when ventricles contract.

Semilunar (SL) Valves

Aortic and Pulmonary valves; open to allow blood ejection and close to prevent backflow.

Coronary Circulation

Heart’s own blood supply via coronary arteries and veins.

Coronary Arteries

Arteries that supply oxygenated blood to the heart muscle.

Coronary Veins

Veins that drain blood from the heart muscle into the coronary sinus.

Endomysium

Connective tissue matrix that surrounds cardiac muscle fibers and connects them to the cardiac skeleton.

Intercalated Discs

Discs containing gap junctions that enable electrical coupling between cardiac cells.

Location of the Heart

Located in the mediastinum between the second rib and the fifth intercostal space.

Coverings of the Heart

Pericardium—the double-walled sac surrounding the heart.