components of blood 2.2.3

• the components of blood is:

  • red blood cells (45%)
  • white blood cells (<1%)
  • platelets (<1%)
  • plasma (55%)
• water in plasma is:

  • a transport medium for transporting all components of the blood
  • a solvent to dissolve other substances
• the dissolved nutrients in plasma are:

  • glucose (energy from respiration/to make carbohydrates)
  • amino acids (used by cells to make new proteins)
  • fatty acids/glycerol (used by cells to make new lipids)
  • vitamins (used to help regulate metabolism inside cells)
• oxygen in plasma is:

  • needed by mitochondria for aerobic respiration
• carbon dioxide in plasma is:

  • produced by cells and carried to the lungs
  • a waste product from aerobic respiration which needs to be removed from the body by the lungs
• urea in plasma is:

  • formed in your liver from the breakdown of excess proteins
  • carried to your kidneys where it is removed from your blood to form urine
• hormones in plasma is:

  • involved in homeostasis
  • controls development in the body~
• dissolved mineral ions in plasma:

  • help control water movement into and out of cells by osmosis
  • some help regulate metabolism inside cells
• plamsa proteins in plasma:

  • are needed to help blood clot
  • help with the reabsorption of fluid from tissues to blood
• plasma is the liquid that carries everything in blood, it is pale straw like fluid that carries:

  • red and white blood cells and platelets
  • nutrients like glucose and amino acids
  • carbon dioxide from the organs to the lungs
  • urea from the liver to the kidneys
  • hormones
  • proteins
  • antibodies and antitoxins produced by the white blood cells
• someone may need a blood transfusion if they lose a lot of blood, for example:

  • injury
  • giving birth
  • knife wounds
  • surgery
• the problems with blood transfusions are that:

  • there are a shortage of donors
  • blood can only be stored for a limited amount of time
  • the blood must match the receivers group
  • some people wont accept blood for religious reasons
• solutions for blood transfusions are:

  • make it compulsory for healthy people to donate blood
  • only take blood when its needed
  • make sure you have enough blood for each blood group
  • give religious persons artificial blood
• red red blood cells function is to carry oxygen from the lungs to all the cells in the body
• red blood cells are biconcave disc shaped which give them a large surface area for absorbing oxygen
• red blood cells are adapted by:

  • having no nucleus so they can fit in more haemoglobin so it can bind to more oxygen (however this does limit their life span to 12 days)
  • having a biconcave disk shape which gives them a larger surface area to volume ratio to absorb oxygen quicker
• red blood cells contain a red pigment called haemoglobin which can bind reversibly to oxygen
• in the lungs, haemoglobin binds to oxygen to become oxyhaemoglobin, whereas in body tissues the reverse happens, oxyhaemoglobin splits up into oxygen and haemoglobin to release oxygen to the cells
• white blood cells (phagocytes) are produced in the bone marrow
• phagocytes swarm to the site of infection and engulf and destroy viruses and bacteria
• phagocytes form part of the immune system
• white blood cells defend against infection
• phagocytes are adapted to be able to change shape to be able to fit out of capillaries to reach the site of infection
• white blood cells (lymphocytes) are produced in bone marrow
• lymphocytes produce antibodies which are specific to one type of microbe and bind to antigens on the surface of foreign cells
• white blood cells do have a nucleus
• platelets help blood to clot
• platelets are produced in the bone marrow
• platelets do not have a nucleus
• platelets are adapted as when platelets are exposed to air or the collagen in blood vessel walls, it causes the formation of dense mesh that traps new blood cells
• platelets are small fragments of cells
• the platelets clots dry to form scabs which have two functions:

  • stop bacteria entering
  • stop blood escaping