Homeostasis

• Glucose is needed for

  cellular respiration
• Glucose levels need to be maintained to avoid

  • Hypoglycaemia
  • Hyperglycaemia
  • Gestational Diabetes
• Glucagon is also produced by the pancreas, it raises blood glucose levels.
• Insulin is produced by the pancreas, it lowers blood glucose levels.
• Key organs/ gland involved in blood glucose regulation

  • pancreas
  • liver
  • adrenal gland
• Homeostasis is


  Maintenance of an optimal set of internal conditions
• Internal Environment

  the fluid environment that surrounds the body's cells
• Nervous System + Endocrine System = Homeostasis
• Nervous System is better for

  Some conditions that need immediate changes as suboptimal conditions can be life threatening
• Endocrine System is better for


  the conditions that need slower, more broad and longer lasting changes
• Feedback System/ Effective Mechanisms

  • Detects Change
  • Decide and controls change
  • Produce effect for change
• Feedback System Type of Responses

  • Positive Feedback
  • Negative Feedback
• Positive Feedback

  • Amplifies/ reinforces the stimulus
  • Homeostasis is not involved
• Negative Feedback

  • Alters/ reduces the stimulus
  • Homeostasis is involved
  • steady state control system
• Metabolism

  sum of all chemical reaction in the body for normal functioning
• Thermoregulation is the response of regulating body temperature
• Basal Metabolic Rate (BMR)


  the amount of energy per unit of time that person needs to keep the body functioning at rest
• The hormone that controls the rate of metabolism in cells is thyroxine
• thyroxine causes the metabolic rate to increase
• Thyroid Secretion Helps Regulate

  • metabolic rate
  • temperature regulation
  • heart rate
  • growth rate
  • storage of calcium
• Hypothyroidism

  • under secretion of thyroxine
  • less ATP produced
  • less heat production
  • bigger In body size
• Hyperthyroidism

  • over secretion of thyroxine
  • increase metabolism rate
  • increase heat production
  • fatigue
  • excessive weight loss
• Glucose is needed for energy -> cellular respiration
• 500g in the body = 100g in the liver + 400g in the muscle
• Glycogenesis = Glucose -> Glucagon (stored)
• Glycogenesis uses insulin from pancreas
• Glycogenolysis = Glucagon -> Glucose (used)
• Glycogenolysis uses glucagon from pancreas
• Beta cells = insulin
• Alpha cells = Glucagon
• Glycogenesis is the formation of glycogen from other carbohydrates
• Glycogenolysis is the break down of glycogen into glucose
• Gluconeogenesis is the conversion of fat or protein into glucose