Mammalian Heart

• Mammalian Heart


  • Mass of around 300g
  • Roughly the size of a closed fist
  • Hollow, muscular organ
  • Located in the chest cavity
  • Protected by the pericardium
• Heart chambers


  • Two top chambers are atria
  • Two bottom chambers are ventricles
• Septum


  • Wall of muscular tissue that separates the left and right sides of the heart
  • Interatrial septum separates the left and right atria
  • Interventricular septum separates the left and right ventricles
• The septum is very important for ensuring blood doesn't mix between the left and right sides of the heart
• Heart valves


  • Open when the pressure of blood behind them is greater than the pressure in front of them
  • Close when the pressure of blood in front of them is greater than the pressure behind them
  • Keep blood flowing forward in the right direction and stop it flowing backwards
  • Maintain the correct pressure in the chambers of the heart
• Heart valves


  • Tricuspid valve (between right atrium and right ventricle)
  • Pulmonary valve (between right ventricle and pulmonary artery)
  • Mitral valve (between left atrium and left ventricle)
  • Aortic valve (between left ventricle and aorta)
• Blood vessels bringing blood to the heart

  • Vena cava
  • Pulmonary vein
• Blood vessels taking blood away from the heart

  • Pulmonary artery
  • Aorta
• Coronary arteries


  • Arteries on the surface of the heart that supply it with blood for aerobic respiration
  • Important that they remain clear of plaques to prevent angina or heart attack
• Dissections are a vital part of scientific research as they allow for the internal structures of organs to be examined so that theories can be made about how they function
• There are ethical concerns surrounding dissections, such as how the animals are raised and killed, and going against the religious beliefs of some individuals
• The biological specimen used for dissection should be from a reputable source and should be disposed of in the correct manner
• If multiple specimens are being dissected then they should be taken from individual organisms of the same species and roughly the same age
• Apparatus for mammalian heart dissection

  • Scissors
  • Scalpel
  • Tweezers / Forceps
  • Dissection board
  • Paper towels
  • Biological specimen
  • Pins
  • Gloves
  • Goggles
• Mammalian heart dissection method

  1. Wear a lab coat, gloves and eye protection

  2. Place the specimen on the dissecting board

  3. Use tools to access the desired structure

  4. Cut away from your body and keep fingers away from the blade when using the scalpel

  5. Use scissors for cutting large sections and scalpel for finer, more precise cutting
• It can be hard to see some of the smaller, finer structures within organs during a dissection
• The specimens do not reflect how the tissue would look in a living organism
• If only a single specimen is dissected then anomalies found within that specimen may be ignored or glossed over