The Circulatory System 

Functions of blood

• %%Transport%%
  • Carries oxygen, nutrients and hormones to cells
  • Carries waste back from them
  • Water
  • CO2
• %%Defence%%
  • Destroys bacteria
  • Destroys blood clots
• %%Controls body temperature%%
  • 37 degree

Composition of blood

• %%Plasma%%

  • Liquid of blood
  • Transports and carries

• %%Red blood cells%%

  • Red: haemoglobin
  • Carries oxygen
  • no nucleus

• %%Platelets%%

  • Clots blood
  • no nucleus

• %%White blood cells%%

  • Fights infections
  • Makes anti-bodies or engulfs the infection
  • Nucleus

Blood vessels

• %%Artery%%: carries blood away from the heart

  • Thick wall
  • Small lumen
  • High pressure
  • No valves
  • Goes away from heart
  • High in O2

• %%Veins%%: carries blood to the heart

  • Thin wall
  • Big lumen
  • Low pressure
  • Valves
  • Goes to heart
  • Low in O2

• %%Capilaries%%: links arteries to veins

  • Very tiny wall
  • Tiny lumen
  • Low pressure
  • No valves
  • Artery to vein

Heart

• The heart is a pump

• Cardiac: to do with heart

  

Pulse

• Pressure of blood in arteries
• %%72 bpm%%

Can be effected by:

• %%Age%%
• %%Diet%%
• %%Gender%%
• %%Stress%%
• %%Exersise%%

Why does the pulse increase with exercise

• Exercise needs energy
• More respiration
• More toxic Co2 made
• Pump blood faster to get rid of the Co2
• More O2 and food is brought to the cells for respiration