heart stuff

Sinoatrial Node (SA node)

The heart's primary pacemaker located at the start of the right atrium, responsible for setting the rhythm of heartbeats.

Atrioventricular Node (AV Node)

A structure located near the tricuspid valve that receives electrical impulses from the SA node and helps regulate heart rhythm.

Purkinje Fibers

Specialized muscle fibers that distribute electrical impulses throughout the ventricles to ensure coordinated contraction.

Autonomic Nervous System

The part of the nervous system that regulates involuntary bodily functions, including heart rate.

Sympathetic Nervous System

Part of the autonomic nervous system that triggers the fight or flight response, increasing heart rate during stress.

Parasympathetic Nervous System

Part of the autonomic nervous system that promotes relaxation and decreases heart rate.

Tachycardia

A condition where the heart rate exceeds 100 beats per minute.

Heart Murmur

An abnormal sound associated with the closure of heart valves, often caused by improper closure.

Diastole

The phase of the heartbeat when the heart muscles are relaxed and chambers fill with blood.

Systole

The phase of the heartbeat when the heart muscles contract and pump blood out of the chambers.

Atrioventricular Valves

Valves located between the atria and ventricles, specifically the mitral and tricuspid valves.

Semilunar Valves

Valves that separate the ventricles from the arteries, specifically the aortic and pulmonary valves.

Electrocardiogram (ECG or EKG)

A test that records the electrical activity of the heart over a period of time.

Myocardial Infarction

Commonly known as a heart attack, occurring when blood flow to a part of the heart is blocked.

Premature Ventricular Contractions

Abnormal heartbeats that start in the ventricles, often causing feelings of a skipped beat.