Heart Structure and Function

Created by

@DarlingParabola

Study Notes

The heart is located in the thoracic cavity, between the lungs, and slightly to the left of the sternum.
It is protected by the rib cage and lodged in a fibrous sac called the pericardium.

Epicardium: the outermost layer, a thin layer of connective tissue that covers the heart.
Myocardium: the middle layer, made up of cardiac muscle cells that contract to pump blood.
Endocardium: the innermost layer, a thin layer of epithelial tissue that lines the heart chambers.

Right Atrium: receives oxygen-depleted blood from the body through the superior and inferior vena cavae.
Right Ventricle: pumps oxygen-depleted blood from the right atrium to the lungs through the pulmonary artery.
Left Atrium: receives oxygen-rich blood from the lungs through the pulmonary veins.
Left Ventricle: pumps oxygen-rich blood from the left atrium to the rest of the body through the aorta.

Atrioventricular Valves: prevent backflow of blood from the ventricles to the atria.
- Tricuspid valve: between the right atrium and ventricle.
- Mitral valve: between the left atrium and ventricle.
Semilunar Valves: prevent backflow of blood from the arteries to the ventricles.
- Pulmonary valve: between the right ventricle and pulmonary artery.
- Aortic valve: between the left ventricle and aorta.

Situated in the thoracic cavity, between the lungs, and slightly to the left of the sternum, the heart is protected by the rib cage and lodged in a fibrous sac called the pericardium.

The heart wall consists of three layers: epicardium, myocardium, and endocardium.
Epicardium: the outermost layer, a thin layer of connective tissue covering the heart.
Myocardium: the middle layer, composed of cardiac muscle cells that contract to pump blood.
Endocardium: the innermost layer, a thin layer of epithelial tissue lining the heart chambers.

The heart has four chambers: right atrium, right ventricle, left atrium, and left ventricle.
Right Atrium: receives oxygen-depleted blood from the body through the superior and inferior vena cavae.
Right Ventricle: pumps oxygen-depleted blood from the right atrium to the lungs through the pulmonary artery.
Left Atrium: receives oxygen-rich blood from the lungs through the pulmonary veins.
Left Ventricle: pumps oxygen-rich blood from the left atrium to the rest of the body through the aorta.

The heart has four valves that prevent backflow of blood: atrioventricular valves and semilunar valves.
Atrioventricular Valves:
- Tricuspid valve: located between the right atrium and ventricle.
- Mitral valve: located between the left atrium and ventricle.
Semilunar Valves:
- Pulmonary valve: located between the right ventricle and pulmonary artery.
- Aortic valve: located between the left ventricle and aorta.