BIOL 1412 Lecture Notes - Lecture 1: Endocrine System, Biological System, Thermostat

• School: University of Manitoba
• Department: Biological Sciences
• Course: BIOL 1412
• Professor: Messing

Document Summary

Principal of homeostasis constancy of internal environment. Cells can only survive within a narrow range of conditions. ph, temperature, co2, bp, wastes, icf, ecf volumes: must be maintained within physiological limits. Nervous and/or endocrine systems control the other systems therefore they: maintain homeostasis or, permit departures from homeostasis in a controlled manner, pregnancy, growth, sudden fright, etc. To regulate homeostasis: the change in the internal environment must be detected or anticipated, n and/or e response alters the system(s) responsible for that condition, a) anticipatory response. Increase respiratory rate at the start of exercise ( before blood gases change: propriocepters signal movement and may be learned or behavioral. Putting on a coat before going out into the cold: feedback mechanisms, mechanisms that respond to a change in the system. Negative feedback: most common homeostatic control mechanism, result of output moves the variable back towards the setpoint, in opposite ( negative) direction to change that triggered the response.