Organisation

• Catalyst

  • a substance that increases the speed of a reaction, without being changed or used up in the reaction.
• Each enzyme has an active site with a unique shape that fits onto the substance involved in a reaction.
• Amylase is an example of a carbohydrase. It breaks down starch.
• Amylase is made in three places:

  • salivary glands
  • pancreas
  • small intestine
• Lipases convert lipids into glycerol and fatty acids. Lipases are made in two places: the pancreas and the small intestine.
• Bile is produced in the liver
• Bile is stored in the gall bladder before its released into the small intestine
• Bile emulsifies fats which makes digestion faster.
• Enzymes used in the digestive system are produced by specialised cells in glands and in the gut lining
• Salivary glands

  • produces amylase enzyme in the saliva
• Stomach

  • pummels the food with its muscular walls
  • produces the protease enzyme
• Liver

  • where bile is produced
• Pancreas

  • produces protease, amylase and lipase enzymes. It then releases these to the small intestine
• Gall bladder

  • where bile is stored before releasing it to the small intestine
• large Intestine

  • where excess water is absorbed
• Small Intestine

  • produces protease, amylase, and lipase to complete digestion
  • where digested food is absorbed out of the digestive system
• Rectum

  • where the faeces are stored
• The lungs are surrounded by the plural membranes
• In the lungs, the air that we breathe in goes through the trachea. This the splits into two tubes called bronchi (one - bronchus)
• Bronchi split into smaller tubes is called bronchioles.
• Alveoli

  • where gas exchange happens
• Circulatory system- heart, blood vessels, blood
• Double circulatory system - two circuits joined together
• right ventricle pumps deoxygenated blood to the lungs. the blood then returns to the heart.
• the left ventricle pumps oxygenated blood around all the other organs.
• The heart is a pumping organ that keeps blood flowing around the body. It is mostly made of muscle tissue
• The heart has valves to keep the blood flowing in the right direction.
• The heart has four chambers:

  1. right atrium
  2. right ventricle
  3. left atrium
  4. left ventricle
• An artificial pacemaker is used to control heartbeat if the natural pacemaker cells don't work properly. It is a little device implanted under the skin and has a wire going to the heart.
• artery/ arteries

  • carry blood away from the heart
  • pumps the blood out at a high pressure so the walls are strong and elastic
  • contains thick layers of muscle
  • contains elastic fibres to allow them to stretch and spring back
• Capillaries

  • thin wall - one cell thick
  • tiny - too small to see
  • permeable walls
  • carries the blood really close to every cell in the body to exchange substances
  • supply food and oxygen
  • takes away waste like CO2
• Veins

  • takes blood back to the heart
  • bigger lumen
  • has valves to keep the blood flowing in the right direction
• Blood is a tissue. It is a huge transport system
• Red Blood Cells

  • carries oxygen
  • biconcave disc
  • large surface area
  • don't have a nucleus
  • has a red pigment - haemoglobin
• White Blood Cells

  • can change shape to unwelcome microorganisms using phagocytosis
  • produces antibodies and anti toxins
• platelets

  • help blood clot
  • small fragments of cells
  • no nucleus
  • lack of this can cause excessive bleeding and bruising
• plasma

  • pale straw-coloured liquid
  • carries everything - rbc,wbc, platelets, co2,urea, hormones, proteins, antibodies, antitoxins
• cardiovascular disease

  • a term to describe diseases of the heart or blood vessels
• coronary heart disease

  • when the coronary arteries that supply the blood to the muscle of the heart get blocked by layers of fatty material building up.
• STENTS

  • tubes that are inserted inside arteries
  • keeps them open so blood can pass through