Chapter 1

• Physiology


  Study of how structure and function of the animal body works together to allow behavioral responses to environment
• Physiology


  • Integrative (affected & affects)
  • Shaped and limited by chemical and physical properties of environment and evolutionary relationships
• Environmental limitations


  • Aquatic environment (changing through history)
  • Terrestrial environment (changing through history)
• Aquatic environment


  • Always wet
  • Less light
  • More dense, more viscous
  • Oxygen hard to extract
  • Abundant suspended nutrients
• Terrestrial environment


  • Always dry
  • More light
  • Less dense, less viscous
• Life is based on carbon, water as solvent, chemical bonds and light as life-sustaining energy sources
• Environmental factors


  • Light
  • Temperature
  • Water
  • pH
  • Radiation
• Hyperthermophilic organisms


  Inhabit high-temperature environments and require specialized cell components like proteins and membranes to be stable and function at these temperatures
• Methanogenic archaea


  Organisms that produces methane in anaerobic conditions, limited by the solubility of lipids in water and protein stability
• If the biochemistry of organisms could be adapted to extreme conditions it would metabolize and reproduce much slower
• Physical and chemical environmental limitations change is earth's history
• Scaling limitations


  • Relationships between characteristics relative to body size
  • Anatomical traits (ex, size of brain may cause limitations)
  • Physiological traits
• Object doubles in size

  Surface area (SA) increases by 4, Volume (V) increases by 8, Surface area to volume ratio decreases
• Surface of organism is involved in exchange of material with the environment, Volume is responsible for the processing and use of these materials
• LARGE ANIMAL


  SA:V small
• SMALL ANIMAL


  SA:V large
• Evolutionary limitations


  • Limited by ancestry characteristics of each animal group
  • Homology similarity due to ancestry
  • Diversity of adaptations to environment is limited by ancestry
  • Analogy similarity due to similar environmental pressures (independent of ancestry)
• Physiological adaptation


  A metabolic or physiologic adjustment within the cell or tissues of organism based on environment, resulting in the improved ability of organism to cope with changing surroundings
• Homeostasis


  Dynamic regulation of animal's internal environment
• Parameters being regulated


  • Temperature
  • pH
  • Dissolved oxygen
  • Glucose
• Conformers


  Animals who do not do homeostasis, their internal environmental varies with the external environment
• Regulators


  Animals that maintain internal stability even as external conditions changes, cannot control internal conditions at environment extremes
• Ectotherms


  Animals that do not have internal control of their body temperature, body temperature is generally similar to the temperature of the environment
• Endotherms


  Animals that maintain a constant body temperature in the face of environmental changes, they generate internal heat that keeps their cellular processes operating optimally even when environment is cold
• Endotherms


  • Fur, fat, or feathers create an insulating layer of air between their skin and internal organs
  • Vasodilation: the opening up of arteries to the skin by relaxation of their smooth muscles brings more blood and heat to the body surface, facilitates radiation and evaporative heat loss to cool the body
  • Vasoconstriction: the narrowing of blood vessels to the skin by contracting smooth muscles reduces blood flow in peripheral blood vessels, forces blood towards the core and vital organs, conserves heat