Anatomy of the Circulatory System

Circulatory System Anatomy

• Purpose: Deliver oxygenated blood to cells and organs for cellular respiration.
• Cell Types: Cardiac muscle (heart) and smooth muscle (vessels).
• Major Organs: Heart, major muscle that pumps blood.
  • Pumps deoxygenated blood to lungs for oxygenation.
  • Pumps oxygenated blood to body through aorta.
  • Valves regulate blood flow between chambers.
• Cardiovascular System: Heart and circulatory system combined.
• Heart Function: Acts as a pump to push blood throughout organs and tissues, delivering oxygen and nutrients and removing waste.
• Blood Circulation: Complex network of arteries, arterioles, capillaries, veins, and venules carry blood.
  • Systemic Circulation: Blood travels from heart to body and back.
    • Arteries carry oxygenated blood away from heart.
    • Veins carry deoxygenated blood back to heart.
  • Pulmonary Circulation: Blood travels to lungs for gas exchange.
    • Pulmonary artery carries deoxygenated blood to lungs.
    • Pulmonary vein carries oxygenated blood back to heart.

Heart Anatomy

• Size: Roughly fist-sized
• Location: Between lungs, behind sternum (breastbone) and slightly left.
• Protection: Surrounded by a double-layered membrane (pericardium).
• Chambers: Four chambers:
  • Upper: Left and right atria.
  • Lower: Left and right ventricles.
• Septum: Wall separating atria and ventricles (both left and right).

Heart Valves

• Function: Regulate blood flow through heart.
• Types:
  • Tricuspid valve: Between right atrium and ventricle.
  • Pulmonary valve: Between right ventricle and pulmonary arteries.
  • Mitral valve: Between left atrium and ventricle.
  • Aortic valve: Between left ventricle and aorta.

Coronary Arteries

• Function: Supply oxygenated blood to heart muscle.
• Branches: From the aorta (main blood supplier).
  • Right coronary artery: Supplies right side of heart.
  • Left coronary artery: Supplies left side of heart, larger and more muscular due to supplying more of the body.

Vascular System (Blood Vessels)

• Components: Arteries, veins, and capillaries.
• Arrangement: Parallel throughout body, with capillaries connecting them.
• Regulation:
  • Arteries: Use vessel size controlled by sympathetic nervous system.
  • Veins: Use one-way valves and muscle contractions.

Organ System Interactions

• Lungs: Exchange oxygen and carbon dioxide.
• Digestive System: Absorb nutrients.
• Excretory System: Filter blood; remove waste.
• Nervous System: Regulate heart rate and blood pressure.