Internal Structure

• Overview

  • Left side contains oxygenated blood
  • Right side contains deoxygenated blood
  • Blood never mixes
  • Atria receive blood
  • Ventricles pump blood
• Right Atrium

  • Receives deoxygenated blood.
  • Superior vena cava transport deoxygenated blood from head and arms to the heart.
  • Inferior vena cava transport deoxygenated blood from lower limps and abdomen to the heart.
• Right Ventricle

  • Pumps deoxygenated blood to the lungs via the pulmonary artery.
• Left atrium

  • Receives oxygenated blood from lungs via the pulmonary vein
• Left Ventricle

  Pumps oxygenated blood via the aorta.

  Largest chamber
• Atrio-ventricular opening

  • Blood from LA goes to LV
  • Blood from RA goes to RV.
• Mechanisms controlling heart beats

  • Cardiac muscles contract and relax without external stimuli
  • Each cardiac cycle is a heart beat.
• Effect of exercise on heartbeat

  • During exercise, more respiration occurs in the muscles to release more energy.
  • More CO2 is released into the blood.
  • Brain detects excess CO2 and pumps blood faster so that deoxygenated blood can be pumped to the lungs to expel excess CO2.
  • O2 rich blood then reaches the muscles faster.