Homeostasis and response

• The temperature near the brain decreases because blood is cooled in the mouth and cooled blood is sent to the brain
• the thermoregulatory centre sends information to sweat glands in the skin via neurones
• the disadvantages of having a kidney transplant is that it may get rejected and there is a risk from surgery
• Marathon runners often drink sports drinks during a race to replace water that is lost in sweat
• the body need to lose water from the skin to maintain the body temperature
• temperature 6 marker:

  • blood vessels constrict so there's less blood flow to the skin so less energy is lost to the surroundings
  • shivering through muscle contraction which releases energy
• a reflex action is an uncontrollable action which is automatic
• CNS coordinating a reflex action 6 marker:

  • Receptors in the skin detect a stimulus
  • Electrical impulses pass along neurones from the sensory to the relay to the motor neurones
  • Theres synapses between the neurones where the chemical diffuse across the gap
  • The synapses in the CNS cause the hand to pull away as the response
• CNS and Endocrine system comparison:

  • Its slow in the endocrine system whereas its quick in the CNS
  • its longer lasting in the endocrine system and its short lasting in the CNS
  • in the endocrine system, the hormones travel around via the blood whereas in the CNS, the information travels along via neurones
• How hormones control the menstrual cycle:

  • FSH stimulates maturation of the egg
  • Oestrogen inhibits FSH and LH production
  • LH stimulates ovulation
  • Progesterone inhibits FSH and LH production
  • Oestrogen and progesterone maintain the uterus lining