Heart Anatomy and Blood Vessels

Heart Structure

• The heart is a muscular organ that pumps blood throughout the body
• It is divided into four chambers:
  • Right atrium (upper right chamber): receives oxygen-depleted blood from the body
  • Right ventricle (lower right chamber): pumps oxygen-depleted blood to the lungs
  • Left atrium (upper left chamber): receives oxygen-rich blood from the lungs
  • Left ventricle (lower left chamber): pumps oxygen-rich blood to the body
• The heart has four valves that control blood flow between the chambers:
  • Tricuspid valve: between the right atrium and ventricle
  • Pulmonary valve: between the right ventricle and pulmonary artery
  • Mitral valve: between the left atrium and ventricle
  • Aortic valve: between the left ventricle and aorta

Blood Vessel Types

• Arteries: carry oxygen-rich blood away from the heart to the rest of the body
  • Elastic arteries: stretch to accommodate blood pressure changes (e.g., aorta)
  • Muscular arteries: have thick muscle walls to regulate blood pressure (e.g., brachial artery)
  • Distributive arteries: branch into smaller arteries to distribute blood to specific areas (e.g., coronary arteries)
• Veins: carry oxygen-depleted blood back to the heart
  • Superficial veins: located near the surface of the skin (e.g., cephalic vein)
  • Deep veins: located deeper in the body and often accompany arteries (e.g., femoral vein)
• Capillaries: tiny blood vessels where oxygen and nutrients are exchanged with the body's tissues

Artery Vs Vein Function

• Arteries:
  • Carry oxygen-rich blood under high pressure
  • Have thicker walls to withstand pressure
  • Have smaller lumens (inner diameters) to maintain pressure
  • Often have a pulse due to the heart's contractions
• Veins:
  • Carry oxygen-depleted blood under low pressure
  • Have thinner walls and larger lumens to accommodate blood flow
  • Often have one-way valves to prevent backflow and ensure blood returns to the heart
  • Do not have a pulse due to the low pressure