Week 2 - Homeostasis

• The human body is a complex unit of systems that interact to allow us to breathe, eat, digest, move, react, grow and reproduce
• Our lives depend on the maintenance of a state of physiological balance called homeostasis – meaning 'same state'
• Homeostasis


  Physiological balance maintained in the body
• Control of Homeostasis


  1. Change in environment is a stimulus

  2. Homeostasis maintained by negative feedback loops

  3. Positive feedback loops push the body out of homeostasis
• Homeostasis is basically controlled by the nervous and endocrine system in mammals
• Set point


  The physiological value around which the normal range fluctuates
• Body temperature goes above normal

  Likely suffering from an infection, body raises temperature to fight it
• Body temperature goes below normal range

  Results in Hypothermia, which can lead to death if untreated
• Hypothermia


  Body temperature below normal range
• Hyperthermia


  Body gains more heat than it loses
• Positive feedback loops


  • Maintain the direction of a stimulus
  • Try to extend the stimulus changes
• Negative feedback loops


  • Change the direction of the stimulus
  • Try to cancel out stimulus change
• Anatomical terms


  • Superior
  • Inferior
  • Anterior
  • Posterior
  • Medial
  • Lateral
  • Proximal
  • Distal
  • Superficial
  • Deep
  • Palmar
  • Plantar
• The sagittal plane divides the body or an organ vertically into right and left sides
• The frontal plane divides the body or an organ into an anterior (front) portion and a posterior (rear) portion
• The transverse plane divides the body or organ horizontally into upper and lower portions