Hormonal coordination in humans

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

  The endocrine system
• A hormone is a chemical messenger secreted by a gland
• Hormones travel in the blood to a target organ to cause a response.
• What type of organ secretes hormones?

  Glands
• The pituitary gland controls many other glands in the body
• The pituitary gland is often referred to as the ‘master gland’ because it secretes a wide range of hormones.
• Order the roles of the pituitary gland in the endocrine system.

  1️⃣ Secretes human growth hormone to control human growth

  2️⃣ Stimulates the thyroid gland

  3️⃣ Stimulates ovulation and oestrogen production in the ovaries

  4️⃣ Stimulates sperm and testosterone production in the testes
• What hormone does the thyroid gland secrete?

  Thyroxine
• Thyroxine controls metabolism, heart rate, and body temperature
• The pancreas secretes the hormone insulin, which controls blood glucose levels.
• What hormone does the adrenal gland secrete?

  Adrenaline
• Adrenaline controls the body’s ‘fight or flight’ response.
• Match the gland with its primary hormone and function:

  Thyroid ↔️ Thyroxine - controls metabolism

  Pancreas ↔️ Insulin - controls blood glucose

  Adrenal ↔️ Adrenaline - controls 'fight or flight'
• What hormone do the ovaries secrete?

  Oestrogen
• Oestrogen coordinates the menstrual cycle and the development of female secondary sexual characteristics
• What hormone do the testes secrete?

  Testosterone
• Testosterone controls the production of sperm and the development of male secondary sexual characteristics.
• Which organ monitors and controls blood glucose concentration?

  The pancreas
• Order the steps in the response of the pancreas when blood glucose levels are too high.

  1️⃣ The pancreas secretes insulin

  2️⃣ Insulin binds to receptors on the liver and muscles

  3️⃣ Excess glucose is converted into glycogen

  4️⃣ Glycogen is stored
• When blood glucose levels are too low, the pancreas secretes the hormone glucagon
• How is blood glucose concentration controlled using a negative feedback loop?

  Hormones bring levels back
• Type 1 diabetes is an autoimmune disorder where the pancreas does not produce sufficient insulin.
• What are the treatments for Type 1 diabetes?

  Insulin injections
• Type 2 diabetes occurs when the body’s cells stop responding to insulin
• Type 2 diabetes is often linked with increasing age and obesity.
• How can Type 2 diabetes be treated?

  Diet, exercise, weight loss
• Osmosis is the movement of water from a dilute solution to a concentrated solution through a partially permeable membrane
• Match the process with how ions are lost from the body:

  Sweating ↔️ Ions are lost through sweat

  Urine ↔️ Ions are lost in urine
• Ammonia, which is toxic, is converted into urea in the liver.
• What is the full name of the hormone ADH?

  Anti-diuretic hormone
• ADH is secreted by the pituitary gland in the brain
• Order the steps in the action of ADH when the blood is too concentrated.

  1️⃣ Pituitary gland secretes more ADH

  2️⃣ ADH travels to the kidneys

  3️⃣ Kidney tubules become more permeable to water

  4️⃣ More water is reabsorbed into the blood

  5️⃣ Smaller volume of concentrated urine is produced
• Why is kidney failure dangerous?

  Toxic molecules build up
• Kidney failure can be treated using dialysis or a transplant.
• Kidney dialysis uses a specialist machine to carry out the function of kidneys
• What is the main male reproductive hormone?

  Testosterone
• The main female reproductive hormone is oestrogen
• The menstrual cycle involves the shedding of the uterus lining and ovulation.
• Order the events of the menstrual cycle.

  1️⃣ Uterus lining thickens and eggs mature in the ovaries

  2️⃣ An egg is released from an ovary (ovulation)

  3️⃣ If the egg is fertilized, pregnancy occurs

  4️⃣ If the egg is not fertilized, menstruation occurs
• What is ovulation?

  Release of a mature egg