B1 - Homeostatic Mechanims

• Two hormones control blood glucose levels

  • Glucagon increases the blood glucose levels
  • insulin reduces the blood glucose levels
• Four functions of kidneys

  • produces urine
  • regulates water
  • regulates pH
  • regulates salt balance
• Two effects of dehydration

  • headaches die to the reduction of water around the brain
  • dry skin leading to irritation
• Outline the role of Homeostasis in the body

  • Allow organs to work efficiently
  • Maintenance of water balance in the body
  • Maintenance of PH
• Explain the role of the kidney in osmoregulation

  • removes water from the blood
  • prevents dehydration
  • increases the water reabsorbed
  • In the loop of henley water re-enters capillaries maintaining osmotic potential of the blood
• Outline two different ways the body uses negative feedback to regulate body temperature

  • Temperature is controlled by negative feedback
  • Hypothermia is low body temperature
  • Body temperature is not raised
  • Temperature fall is uncontrolled
• Explain how the body regulates body temperature

  Temperature is controlled by negative feedback (1) 

  Heat is lost through the skin (1) this can be increased by evaporation of sweat (1) 

  The hypothalamus contains thermoreceptors (1) 

  Adipose tissue insulates the body (1) this is reduced in young children (1) 

  Shivering (1) causes heat production through muscle movement (1) 
• Two effects of renal failure

  Organ failure (1) as toxins build up in the blood (1) 

  Dehydration (1) due to increased urination (1) 
• Two different ways the body uses negative feedback to regulate body temperature

  • Shivering - to produce heat
  • Hair standing up - to insulate
• Describe how the failure of homeostatic mechanisms can lead to hypothermia

  • Temperature is controlled by negative feedback
  • Hypothermia is a low body temperature
  • Body Temperature is not raised
  • Temperature fall is uncontrolled
• Function of liver

  • stores glucose as glycogen
  • produces glucagon to raise blood sugar levels
• Role of Homeostasis

  • Maintenance of internal environment
  • Maintenance of glucose levels
  • Maintenance of pH
  • Maintenance of water balance in body
• Role of Arterioles

  • carry blood from arteries to capillaries
• Role of Sweat glands

  • By sweating,
  • Heat is prodcued as a by product
• Explain how heat is produced in the body

  • During exercise, muscles respire, heat is released
  • Breakdown of adipose tissue, when heat is required
  • Digestion of food, produces heat as a by product
• Role of Pancreas


  Produces Insulin

  Produce Digestive Enzymes
• Role of Liver

  • Stores glucose as glycogen
  • Produces Glucagon to raise blood sugar levels
• Functions of Kidney

  • produces urine
  • regulates water
  • regulates pH
  • regulates salt balance
• Effects of Hypothermia

  • Hypothermia happens when you get too cold, body temperature drops below 35 °C
  • Shivering - to increase heat production
  • Slurred Speech - brain metabolism slows
  • Slow Breathing - reduce heat loss
  • Confusion - due to slowed metabolism
• Effects of Dehydration on body systems

  • Renal - urine will become concetrated changes in blood volume
  • Digestive - constipation, bloating - vomitting, diahorrea.
  • Nervous - dizzy, lightheaded, headache, confusion
  • Circulatory - weak irregular heartbeat
  • Respiratory - rapid breathing leading to coma
• Role of Renal System

  • to remove toxins, salts from the blood and manage the bodys water balance through osmoregulation