homeostasis

• define homeostasis.

  regulation of the internal conditions to maintain optimum conditions for function in response to internal and external changes
• what are the 3 internal conditions to keep constant in the human body?

  body temperature, water levels, bloode glucose levels
• if overhydrated, our cell will burst to a less concentrated area as it dies
• if dehydrated, our cell will burst where the soluble becomes in higher soluble as it dies and shrivels up
• what are some examples of what homeostasis does for a hot environment?

  • sweats to cool
  • blood vessels rise to distrubute heat
  • hair lies flat
• what are some examples of what homeostasis does for a cold environment?

  • shiver to regulate blood
  • blood restriction if extreme
  • hair sticks up
• whats the stimulus?

  the change in the environment
• what does the receptor do?

  it recieves the stimulus, an organ or cell detects it
• what is the concentration centre?

  recieves and processes information from receptors around the body to coordinate response
• what is the effector?

  muscles or glands which bring about response which restores optimum levels
• what are some examples of receptors?

  • skin - touch
  • tongue - tastes
  • npse - smell
  • eyes - see
  • ears - noise, position of head
• why are the internal conditions controlled by homeostasis important?

  to maintain optimum conditions for enzymes to work
• wht are the 2 types of effectors?

  muscles, glands
• whats the response the effector makes to the muscle?

  it contracts
• whats the response the effector makes to glands?

  produce and increases hormones
• whats the peripheral nervous system?

  information passed along different types of nerves in order for the nervous system to respond to stimuli
• whats the sensory neurone?

  carries signals from stimuli as an electrical impulse to CNS
• whats a relay neurone?

  passes the electrical impulse, from sensroy neurone to corect the motor neurone
• whats the motor neurone?

  impluse to move to the effector (muscles or glands) carries the electrical impulse from CNS to an effector
• whats the CNS..?

  the brain and spinal cord
• whats the PNS..?

  cranial nerves, spinal nerves, sensory organs
• where do 2 neurones meet?

  chemical diffuser
• what happens to the synapse?

  releases neurotransmitter from the neurones, diffuses across the synapse between neurones

  transmits the impulse to the next neurone
• why does a concious action take longer than a reflex action?

  concious action impulses travels to the brain - CNS, reflexes dont
• how is information passed across a synapse?

  by a neuronransmitter
• how is information passed in neurones?

  by electrical impulses