Homeostasis and response

• Hormones and Homeostasis

  • Principles of hormonal coordination and control
  • Location of the main hormone-producing glands
  • How hormones are used to control blood glucose levels
  • Production and excretion of urea and maintenance of water balance
• Adrenaline

  • Produced by the adrenal glands in times of fear or stress
  • Increases heart rate, boosts delivery of oxygen and glucose to the brain and muscles
  • Prepares the body for 'flight or fight'
• Type 1 diabetes
• Water balance
• Enzymes from glands like the salivary gland pass into tubes called ducts. Endocrine glands are sometimes called ductless glands because the hormones pass into the blood
• Type 2 diabetes
• Type 1 diabetes is caused by the pancreas failing to produce sufficient insulin, resulting in uncontrolled high blood glucose levels and is normally treated with insulin injections
• Water leaves the body from the lungs during breathing, from the skin in sweat and in urine along with ions and urea
• Endocrine System

  1. Made up of glands that secrete hormones directly into the bloodstream

  2. Hormones are chemical messengers carried in the blood to a target organ where they produce an effect

  3. Effects of hormones are slower and act for longer compared to the nervous system
• Control of Blood Glucose

  1. Monitored and controlled by the pancreas

  2. If blood glucose concentration is too high, insulin is released causing glucose to move into cells and excess glucose to be converted to glycogen for storage

  3. If blood glucose concentration is too low, glucagon is released stimulating glycogen to be converted into glucose and released into the blood
• Type 2 diabetes is caused by the body cells no longer responding to insulin, has obesity as a risk factor
• Thyroxine

  • Produced by the thyroid gland
  • Increases the metabolic rate
  • Controls growth and development in young animals
  • Controlled by negative feedback
• Type 2 diabetes is a disorder that:
• Deamination

  In the liver, excess amino acids are converted to ammonia
• Has obesity as a risk factor
• People who suffer from kidney failure may be treated by organ transplant or kidney dialysis
• Kidneys excrete urea, a waste product produced by the liver from the breakdown of proteins and contains nitrogen
• If the concentration of the blood changes

  Body cells will lose or gain too much water by osmosis
• Production of urine by the kidneys

  Filtering the blood, selective reabsorption of useful substances, leaving urea and excess water and ions to form urine in the kidney tubules
• Most of the water, ions, and all urea and sugar are reabsorbed back into the blood in the kidney tubules
• Urea is
• Endocrine glands


  Sometimes called ductless glands because the hormones pass directly into the blood
• The digestion of proteins from food results in excess amino acids
• Conversion of ammonia to urea

  Ammonia is immediately converted to urea and sent to the kidneys for safe excretion
• The thyroid gland is located
• A dialysis machine removes waste products from the blood three times a week
• Type 2 diabetes is treated with a carbohydrate-controlled diet and regular exercise
• ADH controls the water level in the body
• The balance of water and ions in the body is regulated by the kidneys
• Caused by the body cells no longer responding to insulin
• ADH is released by the pituitary gland when the blood is too concentrated
• If a person drinks a litre of water, it will have an effect on ADH release
• Insulin is made