Functional anatomy

• Origin

  The origin of a muscle is the attachment to the bone that does NOT move when the muscle contracts, located at the proximal end
• Insertion

  The insertion is attached to a bone, which moves more when the muscle contracts, attachment is at the distal end
• How do muscles help us move

  • when a muscle contracts, it pulls one of the two bones it is attached to, creating movement
  • muscles work across a joint, altering the joint muscle
  • they work in pairs to produce movement, once a muscle contracts another muscle must contract to return the bone back to its orginial position
• Agonist

  prime mover, is the muscle responsible for movement
• antagonist 


  the muscle which relaxes to allow movement
• Excitability


  The ability of a muscle to contract in response to a chemical and/or electrical signals via nerve impulses from the CNS
• Extensibility


  The capacity of a muscle to stretch beyond its normal resting length E.g. flexibility
• Contractibility 


  The ability of a muscle to contract or shorten
• "All or none" principle


  States that all muscle fibres in a motor unit will contract with 100% force or none at all
• Elasticity


  The ability of a muscle to return to its original resting length after it has been stretched
• Arteries

  • Carries oxygenated blood away from the heart to all the cells of the body except for the pulmonary artery
  • thick muscular walls
  • no valvesblood is pumped under high BP
  • blood is pumped under high BP
• Veins

  • carries deoxygenated blood towards the heart except for the pulmonary veins
  • thin, collarpsed walls
  • has valves
  • blood pumper under low BP
• Capillaries

  • small blood vessels that carry blood to every cell of the body
  • allows diffusion of oxygen to tissues and removal of carbon dioxide
  • thin walls, one cell thick branches off from arterioles and venules to form a network
• Blood

  Fluid that is transported through the pumping action of the heart via the blood vessels to every cell fo the body

  • transports nutrients and waste products
  • regulates bodies temperature
  • protects the body from diseases
• Components of blood

  1. plasma - contains debris of water, nutrients, wastes, ions etc
  2. WBC - destroys bacteria and pathogens
  3. RBC - gives blood its red colour and carries oxygen to the cells and removes carbon dioxide from muscles and organs
• Vasoconstriction

  arteries will constrict in diameter to reduce blood flow to certain parts of the body
• Vasodilate

  arteries will open up increase in diameter to allow more blood to flow to certain areas of the body
• Hypothermia


  when the body gets too COLD, heat needs to be retained for vital organs, blood flow becomes restricted as blood vessels will vasoconstrict to reduce blood flow to the skin so that heat doesn't get lost
• Hyperthermia

  when the body gets too HOT, blood flow is directed to the skin so that heat is lost to the environment via sweating, blood vessels will vasodilate an increase in diameter so more blood flows to the skin
• Systemic circulation

  carries blood from the heart to all the parts of the body (except lungs) and back again
• Pulmonary circulation

  Carries blood from the heart to the lungs and back again
• Function of the circulatory system

  1. circulates blood to the body
  2. transports, O2, H2O and nutrients to the bodies cells
  3. transports CO2 and wastes away from the cells
  4. maintains body temp
  5. WBC fight infections, protects the body from diseases
• Function of the respiratory system

  1. delivers O2 from the atmosphere to the lungs
  2. provides a method for gas exchange within the lungs
  3. creates speech as air passes vocal cords
  4. facilitates sense of smell
  5. expels heat and water vapour when breathing out
• Structure of the respiratory system

  1. Air passage
  2. Lungs
  3. Diaphragm