as content

• the endocrine system

  the system involving glands and hormones in the body

  • gland - specialised group of cells which instructs the body to secrete hormones into the bloodstream
  • hormones travel through the blood to produce diverse and powerful bodily responses
  • acts much more slowly than the nervous system with longer lasting effects
• endocrine system examples

  adrenaline and noradrenaline - released from the adrenal gland during fight or flight, increases heart and breathing rate

  melatonin - released from the pineal gland, makes you feel sleepy

  oestrogen - released by the ovaries, regulates menstruation
• fight or flight process

  A) hypothalamus

  B) sympathetic nervous system

  C) adrenal medulla

  D) adrenaline and noradrenaline released

  E) fight or flight response

  
• effects of the sympathetic response in fight or flight

  increases

  • energy
  • alertness
  • blood flow to muscles
  • heart rate
  • blood pressure
  • respiration rate
  • pupil size

  decreases

  • digestion

  the parasympathetic nervous system has the opposite effect on these processes in 'rest and digest'
• the process of synaptic transmission

  1. the electrical impulses reach the presynaptic ending
  2. the electrical impulses trigger the release of neurotransmitters
  3. neurotransmitters are released from vesicles across the synapse and diffuse across it
  4. neurotransmitters bind with receptors on the postsynaptic membrane
  5. stimulation of postsynaptic receptors by neurotransmitters results in either the excitation or inhibition of the postsynaptic membrane which changes the liklihood of an electrical impulse being sent down the next neuron