The heart; mass transport in animals

• Name them:

  A - right atrium

  B - Left atrium

  C - right ventricle

  D - left ventricle

  
• Name them:

  A - Pulmonary artery

  B - aorta

  C - vena cava

  D - pulmonary vein

  
• What valve lays between the left atrium and left ventricle, AND the right atrium and right ventricle?

  Atrioventricular (AV) valve
• What valve lays near the pulmonary artery and aorta?

  Semi-lunar valves
• Whats the fancy word for heart attack?

  Myocardial infarction
• The role of the coronary arteries is to what?

  supply the heart with blood.
• relaxation of the heart muscle is called...

  Diastole
• what occurs in atria systole?

  volume of atria decreases but preassure increases

  Contraction of the heart muscle is known as systole
• what occurs in ventricular systole?

  When the pressure in the ventricles is greater than the pressure in the atria, the atrioventricular valve close.

  The ventricles then contract, the volume decreases but the preassure increases

  When the pressure in the ventricles is greater than the pressure in the blood vessels, the semi lunar valves open
• Formula for cardiac output

  cardiac output = heart rate × stroke volume
• Cardiac output is the…

  volume of blood pumped out by a ventricle in one minute.
• what is heart rate?

  number of times ventricles contract in a minitue
• what is stroke volume?

  volume of blood pumped out by ventricles in each beat
• How is the heart adapted for its function?

  Left Ventricle

  Thickest walls

  Pumps oxygenated blood to the whole body via the aorta (high pressure needed).

  Valves prevent the backflow of blood and ensure it flows in one direction.

  The septum separates the left and right sides of the heart to:

  • Prevent oxygenated and deoxygenated blood from mixing.
  • Maintain the correct pressure difference between the two sides.
• What are veins?

  flow deoxygenated blood to the heart
• What is an artery?

  flows blood away from the heart, oxygenated
• Arteries carry blood away from the heart, towards bodyily tissues. They have thick walls to withstand high pressures, a narrow lumen to maintain high pressures and a thick layer of elastic fibres to maintain high pressures between pump cycles.
• The function of the veins is to carry deoxygenated blood back to the heart under lower pressure and speed (except in the case of the pulmonary vein where the blood is oxygenated). Their adaptations are having thinner walls and larger lumen, and having valves to prevent the backflow of blood.
• Capillaries have walls only one endothelial cell thick, meaning their walls are very thin. This makes them well adapted for gas exchange, as substances only have to diffuse over a short distance. Additionally, there are many capillaries within a capillary bed.
• what is tissue fluid?

  Tissue fluid is a watery liquid that surrounds cells in tissues.It contains:

  • Oxygen
  • Glucose
  • Amino acids
  • IonsIt allows substances to diffuse between the blood and body cells.
• How is Tissue Fluid Formed?

  Blood is under high hydrostatic pressure at the arterial end of the capillary the arterial end is the START of capillaries where its branched.

  The high preassure forces molecules like oxygen and glucose out forming tissue fluid

  But large molecures like protein remain in the capillaries, lowering water potential at the venule end

  At the venule end, there is low hydrostatic preassure so water re-enters by osmosis (not all tissue fluid)

  remaining tissue fluid is absorbed into the lymphatic system, where later reabsorbed into capillaries
• How Does Tissue Fluid Return to the Circulatory System?

  Via the Capillaries (Directly)

  • At the venous end of the capillary (closer to veins), the hydrostatic pressure inside the capillary is lower because fluid has been lost.
  • Water re-enters the capillaries by osmosis because the blood has a lower water potential

  OR

  Via the Lymphatic System

  • Some tissue fluid drains into the lymphatic system.
  • The lymphatic system is a network of vessels that returns any excess tissue fluid back into the bloodstream near the heart (at the subclavian vein).
• What is a renal artery?

  The renal artery is a major blood vessel that supplies oxygenated blood to the kidneys