biology eoy

• blood is a tissue
• components of the blood plasma

  red blood cells, white blood cells and platelets
• the plasma transports:


  carbon dioxide from the cells to the lungs, produced as a wasted product from aerobic respiration
• the plasma transports:


  urea from the liver to the kidneys. produced by the breakdown of excess proteins in the liver.
• the plasma transports:


  digestive products transported from the small intestine to the cells
• types of white blood cells:

  lymphocytes and phagocytes
• lymphocytes 


  forms antibodies
• phagocytes

  ingest invading bacteria and viruses
• another type of white blood cell will firm antitoxins which counteract the effect if the poison produced by the pathogen
• red blood cells carry oxygen at the lung and transport it to the cells
• feature of red blood cells

  biconcave discs increase surface area for diffusion.

  haemoglobin binds to oxgen.

  no nucleus makes more space for haemoglobin.
• haemoglobin + oxygen

  ->oxyhaemoglobin
• platelets help the blood to clot at the site of the wound. blood clotting is controlled by enzymes.
• a scab is comprised of protein fibres that capture white blood cells (pus), red blood cells and platelet.
• scabs are produced to protect new skin and stop bacteria entering through the wound
• arteries take blood away from the heart.
• veins carry blood back to the heart
• capillaries are thin for exchange
• the right side of the heart sends blood to the lungs
• the left side of the heart takes blood to the body
• the right side pumps deoxygenated blood to the lungs
• the left side pumps oxygenated blood to the organs of the body
• ventricular walls are thicker because they have to pump blood further
• the left ventricle wall is thicker than the right because it pumps blood around the body while the right pumps to the lungs
• statins are drugs prescribed to reduce blood cholesterol level. they slow rate at which fatty material is deposited in the coronary artery.
• stents open blocked arteries. a metal mesh placed in artery. inflated balloon is inside mesh opening it up. balloon is deflated and removed
• bypass directs blood around blocked arteries. blood vessels are removed from leg and attached to the aorta.
• leaky valves


  mechanical: long lasting, requires medicine to prevent blood clotting

  biological: pig, cattle, or human. only last 12-15 years
• artificial pacemaker controls the rhythm of the heart
• phloem transports sugars and nutrients
• xylem transports water minerals and ions
• transpiration is the loss of water vapour from leaves by evaporation
• potometer is used to measure the rate of transpiration.
• osmosis is the movement of water from an area of high water concentration to an area of low water concentration through a partially permeable membrane