Quiz 1

• Physiology is the study of the normal functioning of living organisms and its component parts
• Emergent properties exist due to many different compartments working together, like nuts and bolts forming a moving vehicle/car
• Teleological approach focuses on the purpose of a physiological process by looking at how it contributes to the overall survival of an organism
• Mechanistic approach focuses on detailed mechanisms and processes underlying a physiological function
• Big themes in physiology:

  • Structure and function
  • Living organisms need energy
  • Information flow coordinates body functions
  • Homeostasis maintains internal stability
• Homeostasis is the process by which living organisms maintain a stable internal environment despite external changes
• When homeostasis fails, the body attempts to compensate:

  • If compensation succeeds, homeostasis is restored
  • If compensation fails, disease may result
• Homeostasis does not equal equilibrium, instead, it maintains a state of disequilibrium
• The law of MASS BALANCE states that if the amount of any substance is to remain constant, any gain must be offset by an equal loss
• To maintain homeostasis, the body must maintain mass balance
• Mass flow is the rate of transport of a substance through the body or into or out of the body
• Homeostatic Control System is a system to keep regulated variables within a normal range/set point
• Negative feedback is homeostatic and opposes or removes a signal
• Positive feedback is not homeostatic and reinforces a stimulus rather than decreasing or removing it
• Temperature regulation is linked to metabolic heat production
• Humans are homeothermic, with an average body temperature of 37°C and a range of 35.5 to 37.7°C
• Factors that cause body temperature to change include exercise, eating a meal, time of day, and the menstrual cycle
• Heat balance in the body depends on input and output
• Heat loss from the body occurs through conductive, radiant, convective, and evaporative heat loss
• The autonomic control of body temperature involves central and peripheral thermoreceptors monitoring skin and core temperature
• Blood vessels constrict in cold temperatures and dilate in hot temperatures to regulate heat loss or gain
• Sweat production and evaporation help in surface heat loss
• Body heat production includes unregulated heat production from voluntary muscle contraction and metabolism, and regulated heat production for maintaining temperature homeostasis
• The body's thermostat can be reset, leading to conditions like hot flashes, fever, hyperthermia, and hypothermia
• Pathological conditions related to body temperature include hyperthermia (heat exhaustion, heat stroke, malignant hyperthermia) and hypothermia