Homeostasis

1
Homeostasis

• Motivated Behaviors
• Temperature Regulation
• Fluid (water) Regulation
• Food/Energy Regulation
• Negative Feedback Systems
• Unavoidable Losses

2
Temperature Regulation

• Endothermic
• Metabolism
• kCal
• Ectothermic

3
Gain/Conserve/Dissipate Heat

• Heat Gain
• Thyroid
• Brown Fat
• Shivering
• Other Behaviors
• Body Surface Exposure
• External Insulation
• Change surroundings
• Torper

4
Gain/Conserve/Dissipate Heat

• Dissipate Heat
• Blood vessel constriction
• Evaporation
• Conduction
• Insulation

5
Gain/Conserve/Dissipate Heat

• Brain Regulation
• Preoptic Area of Hypothalamus

6
Fluid Regulation

• Extracellular vs. Intracellular compartments
• Osmosis
• Osmotic Pressure

7
Fluid Regulation

• Thirst
• Hypovalemic
• Vasopressin
• Renin-Angiotensin
• Osmotic
• Osmosensory Neurons
• Hypothalamus
• POA
• SON
• OVLT
• Secondary Thirst

8
Renin-Angiotensin System

• Renin
• Angiotensin I, II and III
• Circumventricular Organs