Structure of the heart, movement of blood through the heart, types of blood vessel

1. Structure of the Heart

Key Parts and Function:

Part

Function

Atria (right & left)

Receive blood into the heart

Ventricles (right & left)

Pump blood out of the heart

Valves (e.g., tricuspid, bicuspid/mitral, semilunar)

Prevent backflow of blood

Aorta

Carries oxygenated blood to the body

Pulmonary artery

Carries deoxygenated blood to the lungs

Pulmonary vein

Carries oxygenated blood from lungs to heart

Vena cava (superior & inferior)

Carries deoxygenated blood from body to heart

Septum

Wall separating left & right sides of the heart

Key Tip: Right side → deoxygenated blood, Left side → oxygenated blood


🩸 2. Movement of Blood Through the Heart

Step-by-Step Flow:

  1. Deoxygenated blood enters right atrium via vena cava

  2. Blood passes through tricuspid valveright ventricle

  3. Right ventricle pumps blood through pulmonary arterylungs (oxygenated)

  4. Oxygenated blood returns via pulmonary veinleft atrium

  5. Blood passes through bicuspid/mitral valveleft ventricle

  6. Left ventricle pumps blood through aortawhole body

Mnemonic: RA → RV → Lungs → LA → LV → Body


🩺 3. Types of Blood Vessels

Type

Function

Key Features

Arteries

Carry blood away from the heart (usually oxygenated)

Thick, elastic walls; narrow lumen; high pressure

Veins

Carry blood towards the heart (usually deoxygenated)

Thin walls; valves to prevent backflow; wide lumen; low pressure

Capillaries

Exchange materials with tissues

Very thin walls (1 cell thick); narrow lumen; slow blood flow for exchange

Key Tip: Capillaries connect arteries to veins and allow diffusion of oxygen, CO₂, nutrients, and waste


🔗 Big Links

  • Heart structure → ensures unidirectional blood flow

  • Blood movement → linked to oxygenation and deoxygenation

  • Blood vessels → structure matches function (pressure, flow, exchange)


Exam Tips

  • Label heart diagrams with atria, ventricles, valves, arteries, veins

  • When describing blood flow, use right/left side and deoxygenated/oxygenated

  • Compare arteries, veins, capillaries with thickness, lumen, valves, pressure