HOMEOSTASIS

• Physiology


  The study of how living organisms work
• Levels of organization in biological systems

  • Chemical
  • Cellular
  • Tissue
  • Organ
  • Organ system
  • Organism
• Physiology


  • Always interested in function and integration - how things work together at various levels of organization and in the entire organism
• Types of tissues


  • Nervous
  • Muscle
  • Connective
  • Epithelial
• Organ


  Composed of two or more tissues that perform a common function
• Organ system


  Composed of two or more organs that work to perform a common function that is essential to survival
• The human body contains 11 systems
• Homeostasis


  The maintenance of a constant internal environment in the body
• Factors maintained by homeostasis

  • Temperature
  • pH
  • Concentration of nutrients and waste products
  • Concentration of salt and other electrolytes
  • Volume and pressure of extracellular fluid
• Cells that are isolated from the external environment can still exchange materials with the extracellular fluid
• All organisms must maintain a constant internal environment to function properly
• Homeostatic control


  Hormonal control
• Exchange carried out by animals can be described as both internal and external
• Organ systems in mammals

  • Digestive
  • Circulatory
  • Respiratory
  • Immune and lymphatic
  • Excretory
  • Endocrine
  • Reproductive
  • Nervous
  • Integumentary
  • Skeletal
  • Muscular