Heart Anatomy and Circulation

Heart Structure and Function

Location and Function

The heart is a hollow, muscular, cone-shaped organ situated behind the sternum, slightly to the left side of the body. Its primary function is to act as a pump and maintain circulation throughout the body.

Chambers of the Heart

The heart comprises four chambers:

• Atria: Two upper chambers: the left atrium and the right atrium.
• Ventricles: Two lower chambers: the left ventricle and the right ventricle.

Heart Wall Layers

The heart wall consists of three distinct layers:

• Endocardium: The innermost layer of the heart wall.
• Myocardium: The middle layer, composed of cardiac muscle, responsible for the heart's contractions to pump blood.
• Pericardium: The outer layer of the heart.

Valves of the Heart

The heart contains four main valves that prevent the backflow of blood:

• Right Atrioventricular Valve (Tricuspid Valve): Located between the right atrium and the right ventricle. It prevents backflow of blood into the right atrium during the contraction of the right ventricle.
• Left Atrioventricular Valve (Bicuspid/Mitral Valve): Situated between the left atrium and the left ventricle. It prevents backflow of blood into the left atrium during the contraction of the left ventricle.
• Aortic Valve: Positioned between the aorta and the left ventricle. It prevents backflow of blood into the left ventricle.
• Pulmonary Valve: Located between the pulmonary vein and the right ventricle. It prevents backflow of blood into the right ventricle.

Blood Flow and Circulation

• Atria Function: Receive blood flowing towards the heart through veins.

• Ventricle Function: Direct blood away from the heart through arteries.

  • Chordae Tendineae:

Pulmonary Circulation

Pulmonary circulation refers to the circulation of blood between the heart and the lungs, where blood is sent to pick up oxygen.

Major Vessels

• Brachiocephalic artery.
• Superior vena cava
• Right pulmonary arteries.
• Right pulmonary veins,
• Inferior vena cava.