Homeostasis

• What is Homeostasis?

  maintenance of a constant internal environment
• Stimulus -> receptor -> control centre -> corrective mechanisms -> negative feedback (restore to normal conditions)
• Negative feedback

  Opposing stimulus in responses
• What are hormones?

  Chemical substance secreted by an endocrine(ductless) gland. It is transported in the blood plasma to one or target organs and destroyed in the liver.
• • Pancreas is both a exocrine and endocrine gland.
  • Examples of endocrine gland: Pituitary gland, Pancreas
  • Example of exocrine(duct) gland: Pancreatic Duct
• Insulin: excess glucose -> glycogen

  • decrease glucose level by
  • increasing cell permeability to glucose,
  • stimulating liver to convert,
  • increasing oxidation of glucose during respiration
  • These increase rate of glucose uptake by cells
• Type 1 Diabetes Mellitus:

  • Lack of insulin to control blood glucose concn
  • develops early/inherited
  • Treatment: insulin injection
• Type 2 diabetes:

  • Unhealthy diet and obesity (Sedentary lifestyle)
  • Persistently high glucose lvl, glucose in urine, healing of wounds is slow
  • Solutions: Eat healthily, Exercise more
• Sweat gland

  produces sweat and secreted through sweat duct, eventually excreted by skin pores to remove latent heat from body
• Hypothalamus receives stimulus from thermoreceptors in skin of external environment/hypothalamus of blood temperature