Physio+Lecture+1+-+Homeostasis-Feedback+Control 2 (copy)

Define the term “Homeostasis”

It is the ability to maintain a relatively constant internal environment even if the external one fluctuates

what are some factors regulated by homeostasis

concentration of CO2 and O2

pH

Temperature

concentration of waste

concentration of nutrient molecules

what are the basic component of the feedback system

there are 3 basic components of the feedback system which are the sensor, the integrated centre and the effector.

Sensor (or receptor) — watches for change in control variable and sends the info to the integrated centre

the integrating centre — receive info from the sensor and generates an output

effector — receive output from integrating centre

what is the purpose of negative feedback in the body

negative feedback is a mechanism that reverses a deviation from a set point. therefore if a regulated variable increase negative feedback responds by decreasing it (and vice versa)

what are “antagonistic effectors” and are they part of positive or negative feedback

antagonistic effectors oppose changes therefore they lean more towards negative feedback. Most factors in the internal environment are controlled by more than one effector with antagonistic actions (ex, shiver and sweat)

what is positive feedback

it amplifies a change in regulated variable. the body moves further and further from homeostasis

is positive feedback deadly

Yes it is based on the fact that disruption of homeostasis is the basis for disease and death (runaway positive feedback). Positive feedback is only normal when there’s a definite end point to it (ex, childbirth)