biology paper 2

• What is homeostasis?

  Homeostasis is the maintenance of an organisms internal environment from internal and external factors.
• what does homeostasis maintain?

  • body temperature - hot = sweat, cold = shiver
  • blood glucose levels - Insulin = lower blood glucose, glucagon = increase in glucose
  • water levels - high = high volume urine, low = dehydration
• what is the nervous system?

  a system that transmits electrical impulses through cells called neurons.
• what are properties of the nervous system?

  • fast
  • short lasting
  • specific
• path of conscious thought

  stimuli - receptor - sensory neuron - coordinator (brain or spinal chord) - relay neuron - motor neuron - effector (muscles or glands) - response
• what are the gaps between neurons called?

  synapses
• what are properties of Reflexes?

  • rapid
  • involuntary (no conscious part of the brain)
  • to prevent harm or injury
• what do synapses do?

  insure the electrical impulses travel in 1 direction
• what type of neuron is this?

  motor neuron

  
• motor neuron adaptations

  • nucleus - contains DNA and controls the cell
  • long axon - where the impulses travel
  • cell body - many mitochondria for energy
  • myelin strength- travel faster - long axon
• what is the endocrine system?

  A system of glands that produce and secrete hormones into the bloodstream to regulate various bodily functions.
• what gland is nicknamed the 'master gland'

  pituitary Gland
• what does the pituitary gland produce?

  hormones like ADH and FSH
• what does the thyroid gland produce?

  thyroxine
• what does the adrenal gland produce?

  adrenaline
• what does the pancreas produce?

  insulin
• what do the ovaries produce?

  Oestrogen
• what do the testicles produce?

  testosterone
• properties of the endocrine system

  • slow
  • long lasting
  • on a targeted area