animal form and function

• All living organisms interact with the environment
• Animals have evolved diverse adaptations to survive in diverse environments


  • Specialized tissues for biological functions
  • Homeostatic mechanisms
  • Unique energy requirements and metabolic rates
• Anatomy


  The study of the biological form of an organism
• Physiology


  The study of the biological functions an organism performs
• Levels of organization


  • Cells
  • Tissues
  • Organs
  • Organ systems
• Tissue types


  • Epithelial
  • Connective
  • Muscle
  • Nervous
• Specialized tissues and systems require coordination
• Systems for coordination


  • Endocrine system
  • Nervous system
• Homeostasis


  Maintenance of an internal balance regardless of external environment
• Homeostasis is achieved by


  1. Fluctuations above or below a set point serve as a stimulus

  2. Stimulus is detected by a sensor/receptor

  3. Sensor triggers a response
• Homeostasis can involve natural cycles or fluctuations - human circadian rhythm
• Thermoregulation


  Maintenance of an internal temperature within a tolerable range
• Types of thermoregulation


  • Endothermic: generate heat by metabolism; birds and mammals
  • Ectothermic: gain heat from external sources; most invertebrates, fishes, amphibians, and nonavian reptiles
• Metabolic rate


  Amount of energy an animal uses per unit time
• Metabolic rate types


  • Basal metabolic rate (BMR; endotherms)
  • Standard metabolic rate (SMR; ectotherms)
• Endothermy is costly
• Torpor


  Physiological state of low metabolism
• Hibernation


  Long-term torpor