Organisation

• Tissue


  One type of cell carrying out one specific function
• Organ


  Made up of different tissues, carrying out a joint function
• Organ system

  Groups of organs that carry out a function
• Digestive system organs


  • Oesophagus
  • Liver
  • Mechanical mouth
  • Stomach
  • Pancreas
  • Small intestine
  • Large intestine
• Stomach


  • Churns food
  • HCl kills bacteria
  • Provides environment for protease to work
• Pancreas

  • Produces enzymes
• Small intestine


  • Moves glucose, ions etc to blood
  • Produces enzymes
  • Large surface area
• Large intestine


  • Removes excess water
• Lipase


  • Breaks down fats into fatty acids and glycerol
  • Made in pancreas and small intestine
  • Works in small intestine
• Protease


  • Breaks down proteins into amino acids
  • Made in stomach, pancreas, small intestine
  • Works in stomach and small intestine
• Amylase


  • Breaks down starch into sugars
  • Made in salivary glands, pancreas, small intestine
  • Works in mouth and small intestine
• Optimal pH for enzyme activity is around 7
• Respiratory system organs


  • Trachea
  • Bronchus
  • Bronchiole
  • Lungs
• Lungs


  • Large surface area for gas exchange
  • Diaphragm moves up and down to bring air in and out
• Cardiovascular system


  • Double system
  • Pacemaker in right atrium
• Capillaries


  • One cell thick for diffusion
  • Large surface area
• Epidemiological studies look at patterns of health/disease in populations
• Cardiovascular disease can be caused by fatty deposits building up in coronary arteries, formation of blood clots, and blood clots blocking arteries
• Cardiovascular disease risk factors

  • Smoking
  • High blood pressure
  • High salt and fat diet
  • Lack of oxygen to some cells
• Health


  Overall state of physical and mental wellbeing
• Cancer risk factors


  • Smoking
  • Diet
  • Unprotected sex
  • Sun exposure
• Leaf


  • Palisade layer for photosynthesis
  • Spongy mesophyll for gas exchange
  • Stomata for evapotranspiration
• Xylem


  • Carries water up from roots to leaves
• Phloem


  • Carries food and minerals from leaves to roots
• Transpiration


  Evaporation and movement of water away from the plant
• Metabolism


  Sum of all chemical reactions in the body
• Glucose in plants


  • Used to produce cellulose, starch, amino acids
• Glucose in humans


  • Stored as glycogen
  • Excess proteins broken down and urea secreted by kidneys
• Digestive enzymes


  • Convert food into small soluble molecules that can be absorbed into the bloodstream
• Bile


  • Alkaline, neutralises stomach acid