Organization and homeostasis

  • 11 organ systems and major functions 

  • Integumentary, skeletal, muscular, nervous, endocrine, circulatory, lymphatic/immune, respiratory, excretive, and reproductive 

  • 3 exchange systems 

  • Digestive system 

  • Breakdown and absorption of food molecules 

  • Respiratory system  

  • Absorption of oxygen into blood and the excretion of CO2 

  • Excretory system 

  • Osmoregulation and removal of waste from the blood 

  • Transport  

  • Circulatory system 

  • Lymphatic system 

  • Reproductive System 

  • Produces and stores gametes 

  • Fertilization and development of embryos 

  • Integration/coordination/response  

  • Nervous system 

  • Transfer messages between the brain and the body (electrochemical communication) 

  • Endocrine system 

  • Regulates hormones that alter cell function (chemical communication) 

  • Integument, skeletal, muscular systems 

  • Factors needed for survival 

  • Water to maintain chemical concentrations 

  • Nutrients to maintain metabolism 

  • Oxygen to permit energy (ATP) production (metabolic pathways) 

  • Waste removal to prevent toxicity 

  • Constant body temperature for normal body function 

  • Regulated internal pressure for normal body function 

  • What is homeostasis? 

  • Maintain internal balance 

  • The internal balance (equilibrium) that results from regulating the 6 major survival factors 

  • Relies on negative feedback mechanisms 

  • Factors needed for homeostatic system 

  • Steady state vs homeostasis 

  • Negative feedback equilibrium – no E investment at set point 

  • Negative feedback steady state – Still invest E at set point to maintain (ex: body temp via cellular respiration) 

  • Positive feedback mechanisms and examples 

  • After a cut, when body releases clotting factors 

  • Childbirth when hormones trigger uterine contraction 

  • Changes that trigger a fever 

  • Short-lived and movement away from normal