Lecture on the Heart and Circulatory System

These flashcards cover key vocabulary and concepts from the lecture on the heart and circulatory system, providing definitions for important terms and processes.

Mediastinum

The area in the middle of the chest containing the heart, located posterior to the sternum.

Pericardium

The membranous structure that covers the heart, consisting of two layers: fibrous pericardium and serous pericardium.

Fibrous Pericardium

The thick outer layer of the pericardium made of collagenous tissue.

Serous Pericardium

The inner layer of the pericardium, which is composed of two layers: parietal pericardium and visceral pericardium.

Pericardial Cavity

The space between the parietal and visceral layers of the pericardium that contains serous fluid.

Serous Fluid

The lubricating fluid in the pericardial cavity that reduces friction during heart motion.

Epicardium

The outermost layer of the heart wall.

Myocardium

The thick middle layer of the heart composed of cardiac muscle tissue.

Endocardium

The innermost layer of the heart that lines the cavities.

Atria

The two upper chambers of the heart that receive blood; includes right atrium and left atrium.

Ventricles

The two lower chambers of the heart that pump blood away; includes right ventricle and left ventricle.

Pulmonary Circuit

The part of the circulatory system responsible for carrying deoxygenated blood from the heart to the lungs.

Systemic Circuit

The part of the circulatory system that delivers oxygenated blood from the heart to the rest of the body.

Coronary Circulation

The circulation that supplies blood to the heart muscle itself.

Systole

The phase of the cardiac cycle when the heart muscle contracts, pumping blood.

Diastole

The phase of the cardiac cycle when the heart muscle relaxes, allowing the chambers to fill with blood.

Atrioventricular Valves

Valves located between the atria and ventricles; included tricuspid and mitral valves.

Semilunar Valves

Valves located at the bases of the major vessels leaving the heart; includes aortic and pulmonary valves.

Pacemaker Cells

Cells in the heart that maintain rhythm; includes sinoatrial node, atrioventricular node, and Purkinje fibers.

Cardiac Muscle

Striated muscle tissue found in the heart, which contracts to pump blood.

Heart Rate

The number of heartbeats per minute, typically between 60 to 100 beats per minute for a healthy adult.

Arrhythmia

An irregular heartbeat which can be too fast, too slow, or erratic.

Bradycardia

A slower than normal heart rate, usually below 60 beats per minute.

Electrocardiogram (ECG)

A test that measures the electrical activity of the heart and helps diagnose various cardiac conditions.