exchange and transport in animals

• alveoli - microscopic air sacks in the lungs where gas exchange happens
• alveoli

  • adapted for efficient gas exchange
  • large surface area - short diffusion distance
• fick's law - describes the relationship between the rate of diffusion and the three factors that effect diffusion
• rate of diffusion = SA X conc. diff. / thickness
• the rate of diffusion will double if

  • surface area or concentration difference is doubled
  • thickness of exchange membrane has been halved
• blood

  • red blood cells
  • white blood cells
  • platelets
  • plasma
• red blood cells

  • no nucleus
  • biconcave shape
  • thin
• white blood cells - part of bodies immune system

  • phagocytes - engulf and destroy pathogens
  • lymphocytes - produce antibodies
• plasma

  • liquid
  • transports CO2 / hormones / antibodies / urea
• platelets

  • clot blood
• blood vessels

  • arteries
  • veins
  • capillaries
• arteries

  • carry blood away from the heart
  • high pressure
  • thick muscular walls
  • small lumen
• veins

  • carry blood to the heart
  • low pressure
  • valves to prevent back flow of blood
  • large lumen
• capillaries

  • connect small branches of arteries and veins
  • one cell thick walls
  • small diffusion distance
• heart

  • walls are thicker on the left side
  • blood is pumped out to the body at high pressure
• mammals have a double circulatory system
• vena cave

  • right side of heart
  • carries blood to heart
• pulmonary artery

  • right side of heart
  • carries blood to lungs
• aorta

  • left side of heart
  • carries blood to body
• pulmonary vein

  • left side of heart
  • carries blood from lungs to the heart
• heart

  • right atrium
  • right ventricle
  • left atrium
  • left ventricle
  • tendons - open and close valves
• Aerobic respiration

  • oxygen + glucose = carbon dioxide + water
• anaerobic respiration

  • glucose = lactic acid
• aerobic

  • happens in mitochondria
• anaerobic

  • happens in the cytoplasm
• after exercise

  • heart and breathing rate remain high to replace oxygen in the blood
  • needed to produce more energy to get rid of lactic acid
  • need to repay oxygen debt
• heart rate - number of time your heart beats per minute
• stroke volume - volume of blood pushed into aorta each minute
• cardiac output - total volume of blood pump out by the left ventricle each minute

  • CO = SV X HR