ExPhys - Exam 1 terms and graphs

Homeostasis

the maintenance of a constant internal environment

Steady state

describes the tendency of a control system to achieve a balance between an environmental demand and the response of a physiological system to meet that demand to allow the tissue (body) to function over time

biological control system

a control system capable of maintaining homeostasis within a cell or organ system in a living creature

sensor

a receptor in the body capable of detecting change in a variable

control center

a structure in the body that receives and processes information from receptors

effectors

organ or body part that responds to stimulation by an efferent neuron

negative feedback

describes the response from a control system that reduces the size of the stimulus

negative feedback example

an elevated blood glucose concentration causes the secretion of insulin, which, in turn, lowers the blood glucose concentration

positive feedback

describes the response from a control system that increases the size of the stimulus

gain

refers to the amount of correction that a control system is capable of achieving

adaptation

refers to a change in the structure and function of a cell or organ system that results in an improved ability to maintain homeostasis during stressful conditions

acclimation

the change that occurs in response to repeated environmental stresses and results in the improved function of an existing homeostatic system. In general, it is commonly used to refer to a rapid physiological adaptation that occurs within days to a few weeks

cell signaling

a system of communication that governs cellular activities and coordinates cell actions. it can occur via numerous signaling pathways, including direct contact of cells

stress proteins

the term stress protein refers to a family of proteins that are manufactured in cells in a response to a variety of stresses (like high temp). One of the most important families of stress proteins are called heat shock proteins

heat shock proteins

an important family of stress proteins that are produced in cells in response to cellular stresses. following synthesis, heat shock protein can protect cells against disturbances in homeostasis