Ch.17 Cardiac Function flashcards

Cardiac Dysfunction

Abnormal function or death of cells throughout the body due to heart issues.

Cardiovascular Disease

The number one killer in the US.

Cardiac Valves

Structures that control the direction of blood flow through the heart, including Mitral, Tricuspid, Pulmonic, and Aortic valves.

Systole

The period of ventricular contraction in the cardiac cycle.

Diastole

The period of ventricular relaxation in the cardiac cycle.

Stroke Volume (SV)

The amount of blood ejected from each contraction of the ventricle.

End-Diastolic Volume (EDV)

The volume of blood in a ventricle prior to ejection.

End-Systolic Volume (ESV)

The amount of blood remaining in a ventricle after ejection.

Ejection Fraction

The fraction of end-diastolic volume that is ejected during systole.

Isovolumic Contraction

A phase where intraventricular pressure rises, and volume remains constant as the ventricles contract.

Atrial Events

Characteristics waves in the atria, including A wave (atrial contraction), C wave (AV valve bulging), and V wave (atrial filling).

Dicrotic Notch

A reflection of closure of the semilunar valves, indicating a drop in arterial pressure.

Coronary Circulation

The flow of blood to and from the tissues of the heart.

Ohm's Law in Coronary Blood Flow

An increase in pressure leads to an increase in flow; the coronary driving pressure is the difference between aortic blood pressure and right atrial pressure.

Myocytes

Heart muscle cells that can be categorized into working cells and electrical cells.

Excitation-Contraction Coupling

The process where depolarization of the plasma membrane triggers contraction through calcium release.

Sliding Filament Theory

Describes how muscle contraction occurs through actin and myosin filaments sliding past each other.

Lusitropy

Muscle relaxation due to the removal of calcium from the cytoplasm.

Electrocardiogram (ECG)

A recording of the electrical activity of the heart.

Frank-Starling Law

The principle that greater filling of the heart leads to stronger contractions up to a physiological limit.

Autonomic Regulation of the Heart

The sympathetic and parasympathetic nervous system modulates heart rate and contraction strength.

Cardiac Output

The amount of blood the heart pumps in a minute, determined by heart rate and stroke volume.

Natriuretic Peptides

Hormones secreted by the heart in response to stretch, promoting sodium and water excretion.

Cardiac Catheterization

A procedure to measure pressures in heart chambers and visualize the coronary arteries.

Nuclear Cardiac Imaging

Uses radioactive substances to trace blood flow patterns in the heart.