The Heart 4e NOTES Fall 2022 (1)

Circulatory System

A body system responsible for the transportation of blood, nutrients, gases, and waste.

Myocardial Infarction (MI)

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

Atria

Upper chambers of the heart that receive blood entering the heart.

Ventricles

Lower chambers of the heart that pump blood out of the heart.

Pulmonary Circulation

The circuit that carries blood to and from the lungs.

Systemic Circulation

The circuit that carries blood to and from the body tissues.

Pericardium

The fibrous sac that surrounds the heart.

Myocardium

The muscular middle layer of the heart wall.

Endocardium

The innermost layer of tissue lining the heart chambers.

Stroke Volume

The amount of blood ejected by each ventricle in one contraction.

Heart Rate (HR)

The number of times the heart beats per minute.

Cardiac Output (CO)

The amount of blood pumped by each ventricle per minute, calculated as heart rate multiplied by stroke volume.

Pacemaker

The sinoatrial (SA) node, which initiates the heartbeat by generating action potentials.

Electrocardiogram (ECG or EKG)

A recording of the electrical activity of the heart.

Atrioventricular Valves (AV)

Valves located between the atria and ventricles that prevent backflow of blood.

Semilunar Valves

Valves located between the ventricles and arteries that prevent backflow of blood into the ventricles.

Coronary Circulation

The blood vessels that supply blood to the heart muscle itself.

Fossa Ovalis

An oval-shaped remnant in the right atrium of the heart, which was the foramen ovale before birth.

Congestive Heart Failure

A condition where the heart's function as a pump is inadequate to meet the body's needs.

Baroreceptors

Sensors in the arteries that detect blood pressure changes.

Intercalated Discs

Specialized connections between cardiac muscle cells that allow synchronized contraction.

How many chambers does the human heart have?

The human heart has four chambers: two atria and two ventricles.

About how many times per day does your heart beat?

The average human heart beats about 100,000 times per day.

About how much blood is pumped by your heart with each beat?

The human heart pumps approximately 60 to 100 milliliters of blood with each beat, depending on factors like activity level and size.

What is a heart attack/myocardial infarction (MI)?

A heart attack, or myocardial infarction (MI), occurs when blood flow to a part of the heart is blocked, causing damage to the heart muscle. This can result from a buildup of plaque in the coronary arteries, leading to symptoms such as chest pain and shortness of breath.

What are the symptoms of a heart attack?

chest pain, discomfort in other areas of the upper body, shortness of breath, nausea, and cold sweats.