Hormonal Coordination in Humans

• What is the name of the body’s coordination system that involves hormones?

  The endocrine system
• What is a hormone?

  A chemical messenger secreted by a gland
• What type of organ secretes hormones?

  Glands
• Which gland controls many other glands in the body?

  The pituitary gland
• Why is the pituitary gland considered a ‘master gland’?

  It secretes hormones that stimulate other glands
• What is the role of the pituitary gland in the endocrine system?

  • Secretes human growth hormone
  • Stimulates the thyroid gland
  • Stimulates ovulation and oestrogen production
  • Stimulates sperm production and testosterone
• What is the role of the thyroid gland in the endocrine system?

  Secretes thyroxine, controlling metabolism and heart rate
• What is the role of the pancreas in the endocrine system?

  Secretes insulin to control blood glucose levels
• What is the role of the adrenal gland in the endocrine system?

  Secretes adrenaline for the ‘fight or flight’ response
• What is the role of the ovaries in the endocrine system?

  Secrete oestrogen for menstrual cycle coordination
• What is the role of the testes in the endocrine system?

  Secrete testosterone for sperm production
• Which organ monitors and controls blood glucose concentration?

  The pancreas
• How does the pancreas respond when blood glucose levels are too high?

  The pancreas secretes insulin to lower glucose
• How does the pancreas respond when blood glucose levels are too low?

  The pancreas secretes glucagon to raise glucose
• How is blood glucose concentration controlled using a negative feedback loop?

  • Hormone secreted when glucose rises or falls
  • Insulin or glucagon helps restore correct levels
• What is Type 1 diabetes?

  An autoimmune disorder affecting insulin production
• How can Type 1 diabetes be treated?

  • Insulin injections before meals
  • Limiting carbohydrate intake
  • Pancreas transplants and genetic engineering
• What is Type 2 diabetes?

  A disorder where cells stop responding to insulin
• How can Type 2 diabetes be treated?

  • Controlled diet
  • Regular exercise
  • Weight loss
  • Drugs to increase insulin effectiveness
• What is osmosis?

  Movement of water from dilute to concentrated solution
• In what ways is water lost from the body?

  • During exhalation via the lungs
  • Sweating
  • Urine (some reabsorbed in the kidney)
• In what ways are ions lost from the body?

  • Sweating
  • Urine (some reabsorbed in the kidney)
• How are excess amino acids excreted from the body?

  • Deaminated in the liver to form ammonia
  • Ammonia converted to urea
  • Urea excreted via sweat and urine
• How do the kidneys maintain the balance of water and other substances in the body?

  By filtering blood and reabsorbing necessary substances
• In what ways are ions lost from the body?

  Sweating and urine
• How are excess amino acids excreted from the body?

  They are deaminated to form ammonia
• What happens to ammonia after deamination?

  It is converted into urea
• How is urea excreted from the body?

  Via sweat and urine
• How do the kidneys maintain the balance of water and other substances?

  By filtering blood and reabsorbing useful molecules
• What is the full name of the hormone ADH?

  Anti-diuretic hormone
• Where is ADH secreted in the body?

  The pituitary gland of the brain
• How does ADH affect water reabsorption in the kidneys?

  It increases the permeability of kidney tubules
• What happens when blood is too concentrated regarding ADH?

  The pituitary gland secretes more ADH
• Why is kidney failure dangerous?

  It leads to toxic molecule build-up
• What are the two main ways of treating kidney failure?

  Dialysis and transplant
• What is kidney dialysis?

  A machine that performs kidney functions
• What does dialysis fluid contain?

  Same concentration of glucose and ions as blood
• What is the function of reproductive hormones during puberty for males?

  Development of secondary sexual characteristics
• What is the function of reproductive hormones during puberty for females?

  Development of secondary sexual characteristics and egg maturation
• What is the main male reproductive hormone?

  Testosterone