B10 - human nervous system

• What is homeostasis

  The maintenance Of a constant internal environment
• What is an enzyme

  Protein that breaks something down
• What is substrate 


  Something being broken down
• What can change an enzymes active site

  Temp and ph
• How does temperasure effect

  1-as temperature increases the rate of Reaction increases

  2-the kinetic energy increases due to more collisions between active site and substrate

  3-when optimal temperature is reached enzymes denature and the rate of reaction decreases
• What internal conditions are controlled by homeostatis

  Body temp

  Water content of body

  Blood glucose concentration
• what is the control system pathway

  Stimulus- change in internal/external enviroment

  Receptor- detects the stimulus

  Coordinator- receive and process info from the receptor and coordinate a response

  Effector- muscles/glands that bring a response

  Response- action made to restore optimum conditions
• 3 ways your external environment may vary

  Temperature increases

  Level of sunlight increases

  Wind speed increases
• 2 types of nervous systems

  Central nervous system - brain + spinal cord

  Periferal nervous system- everything else
• differemce between neurones and nerves

  Neurone=a single nerve cell

  Nerves= bundles of neurones and a collection of structures (blood vessels)
• Different types of neurones

  Sensory - connects receptors to brain and spinal cord

  Motor- connects CNS to effectors (muscles/glands)

  Relay- connects sensory neurons to motor neurons in the CNS
• What does the nervous system do

  carries electrical impulses that react to changes in an environment
• Order of reflexes

  
  

  (Ronaldo survives reaching Mount Everest)

  
  

  receptor

  sensory neurone

  relay neurone

  motor neurone

  effector
• What is a synapse

  Where neurons connect and communicate with each other
• How do synapses work

  Impulses arrive at The neurone

  The neurone has sacs containing chemicals

  The chemicals are released into the synapse

  The chemicals cross the receptor site and attach to the surface of the new neurone setting a new impulse
• Why are reflexes important

  • The enable us to prevent damage and danger as they happen automatically and fast
  • The control many of the body's vital functions such as breathing, without the need for conscious thought.
• Ruler drop test

  1. Work with a partner.
  2. Person A rests their hand on a table and holds out their hand with a gap between their thumb and first finger.
  3. Person B holds the ruler with the zero at the top of person A's thumb.
  4. Person B drops the ruler without telling Person A and they must catch it.
  5. The number level with the top of person A's thumb is recorded in a suitable table. Repeat this five times.
  6. Swap places, and record another five attempts.
  7. You can use the conversion table to help convert your ruler measurements into reaction time or just record the catch distance in centimetres.