CH5&6 Homeostasis

• Homeostasis


  The maintenance of the body's internal environment regardless of the changes in the external environment
• Steady State


  a state in which inputs equal outputs, so that the system is not changing over time
• Tolerance Limit


  The limit in which. variable can fluctuate while still maintaining overall stability
• What occur at the modulator?


  An electrochemical message telling the kidneys or systems that don't know the body's temperature to initiate a message, as kidneys filter excess substances from the blood that contribute to body temp.
• Feedback System Acronym


  SRMERF
• Thermoregulation


  Maintaining a relatively stable internal temperature, regardless of the external temperature.
• Radiation


  Loss of heat via infrared rays. Warmer objects radiate to cooler surroundings due to the concentration gradient
• Evaporation


  Sweat glands carry heat out of the body as heat moves from hot to cold surroundings, cooling the surface of the skin - liquid to gaseous state
• Conduction


  The loss of heat via direct contact with a cooler object
• Convection


  The transfer of heat by circulation of movement of the heated part of liquid or gas
• Central Chemoreceptors


  Medulla oblongata, detect CO2 and H+ concentration in blood plasma
• Peripheral Chemoreceptors


  Aortic and carotid bodies, detect O2, CO2 and H+ concentrations in blood plasma
• Phrenic nerve


  Provides motor function for the diaphragm
• What the Diaphragm and Intercostal Muscles are Controlled by

  Spinal nerves
• Alpha Cell Stimulus/Response


  Stimulated the there is a low BGL, secreting glucagon hormone
• Lipogenesis


  The formation of fats from glucose to be stored in adipose tissue of the skeletal muscle in between meals
• Glycogenolysis


  The breakdown of glycogen into glucose
• Glycogen


  Polysaccharide made up of thousands of glucose molecules
• Glycogenesis


  Formation of glycogen from glucose
• Glucose


  A monosaccharide; simple sugar
• Beta Cell Stimulus/Response


  Stimulated when there is an increased BGL, secreting insulin hormone
• Lipolysis


  Breakdown of fat into glucose
• Gluconeogenesis


  The formation of glucose from fats and amino acids
• Islets of Langheran Receptor Type

  Chemoreceptor
• Extracellular Fluid


  Fluid between the blood plasma and outside of cells
• Intracellular Fluid


  Fluid in the cell (cytoplasm)
• How do you Gain Fluid? (2)


  1. Drinking and eating

  2. byproduct of cellular respiration
• What do Osmoreceptors Stimulate?

  Thirst centre in the hypothalamus
• How do you Lose Fluid? (4)


  1. Kidney: excretion in urine

  2. Skin: sweating

  3. Surface of lungs: expiration

  4. Alimentary canal: digestion