Hormonal coordination

• What is the endocrine system?

  the system of glands that secrete hormones into the bloodstream.
• Where is the pituitary gland located? What is it also called?

  It is known as the ‘master gland’ and located in the brain
• Which organ monitors and controls blood glucose concentration?

  the pancreas
• What is the role of the thyroid gland?

  Controls the rate of the metabolism in the body
• Where is the thyroid gland located?

  Neck
• Where are the adrenal glands located?

  above the kidneys
• Pituitary:

  • controls child growth
  • stimulates the thyroid gland to make thyroxine - this controls metabolism rate
• Adrenal

  • prepares the body for stress
  • involved in the ‘flight or fight’
• which hormones interact to regulate blood glucose levels?

  Insulin and glucose
• If blood glucose is too high:

  • the pancreas releases insulin
  • the glucose moves from the blood into the cells
  • Excess glucose converted to glycogen in the liver and muscle cells for storage
  • Blood glucose falls
• If blood glucose too low:

  • pancreas releases glycogen
  • glycogen is converted into glucose and released into the blood
  • Amino acids/fats are broken down
  • Blood glucose rises
• Type 1 diabetes:

  • pancreas produces insufficient insulin
  • usually early onset
  • commonly treated with insulin injections, diet control and exercise
• Type 2 diabetes:

  • body cells no longer respond to insulin
  • usually later onset, obesity is a risk factor
  • commonly treated through a carbohydrate controlled diet and exercise
• What is the function of FSH?

  causes eggs to mature in the ovaries, and stimulates ovaries to produce oestrogen
• What is the function of LH?

  Stimulates the release of an egg
• What is the function of oestrogen?

  Causes lining of uterus walls to thicken

  Inhibits release of FSH

  Stimulates release of LH
• What are the methods of hormonal contraception?

  Oral contraceptives - contains hormones to inhibit FSH

  Injections, implants, skin patches, IUD
• What are the methods of no-hormonal contraception?

  Barrier methods - condoms, diaphragms

  Copper IUD - prevents implantation of embryo

  EXTRAS: surgical methods, spermicidal agents, abstinence
• IVF treatment (for infertility)

  • mother given FSH and LH to stimulate maturation of several eggs
  • eggs collected from the mother and fertilised by the sperm of father in a laboratory
  • fertilised eggs develop into embryos
  • embryo(s) inserted into mother’s uterus
• What are the disadvantages of IVF treatment?

  emotionally and physically stressful

  low success rate

  can lead to risky or multiple births
• Name one hormone controlled by negative feedback

  Thyroxine
• Which endocrine glands control secondary sexual characteristics?

  Ovaries in females, testes in males