Heart Structure and Heart Wall

Heart Structure

• The heart is a muscular, hollow organ that pumps blood throughout the body.
• It is divided into four chambers:
  • Right atrium (upper right chamber)
  • Left atrium (upper left chamber)
  • Right ventricle (lower right chamber)
  • Left ventricle (lower left chamber)

Heart Wall

• The heart wall is composed of three layers:
  1. Epicardium: outermost layer, a thin layer of connective tissue
  2. Myocardium: middle layer, thick layer of cardiac muscle
  3. Endocardium: innermost layer, thin layer of epithelial tissue

Septum

• The septum is a thin wall of tissue that separates the right and left sides of the heart
• There are two septa:
  • Interventricular septum: separates the right and left ventricles
  • Interatrial septum: separates the right and left atria

Heart Valves

• The heart has four valves that ensure blood flows in one direction:
  • Tricuspid valve: between right atrium and ventricle
  • Pulmonary valve: between right ventricle and pulmonary artery
  • Mitral valve: between left atrium and ventricle
  • Aortic valve: between left ventricle and aorta

Blood Flow

• Deoxygenated blood enters the right atrium through the superior and inferior vena cavae
• Blood flows from the right atrium to the right ventricle, then to the lungs through the pulmonary artery
• Oxygenated blood returns to the left atrium through the pulmonary veins
• Blood flows from the left atrium to the left ventricle, then to the rest of the body through the aorta

Heart Structure

• The heart is a muscular, hollow organ that pumps blood throughout the body
• It has four chambers: right atrium (upper right), left atrium (upper left), right ventricle (lower right), and left ventricle (lower left)

Heart Wall

• The heart wall consists of three layers: epicardium (outermost, thin connective tissue), myocardium (middle, thick cardiac muscle), and endocardium (innermost, thin epithelial tissue)

Septum

• The septum is a thin wall of tissue separating the right and left sides of the heart
• There are two septa: interventricular septum (separates right and left ventricles) and interatrial septum (separates right and left atria)

Heart Valves

• The heart has four valves that ensure one-way blood flow
• Valves include: tricuspid valve (between right atrium and ventricle), pulmonary valve (between right ventricle and pulmonary artery), mitral valve (between left atrium and ventricle), and aortic valve (between left ventricle and aorta)

Blood Flow

• Deoxygenated blood enters the right atrium through the superior and inferior vena cavae
• Blood flows from right atrium to right ventricle, then to lungs through pulmonary artery
• Oxygenated blood returns to left atrium through pulmonary veins
• Blood flows from left atrium to left ventricle, then to rest of body through aorta