Human Structure and Function 1.4

Define homeostasis

Bodies ability to keep relatively stable conditions, must be maintained to keep body systems stable, every organ system has a role

Variable

Factor or event that needs to be regulated

Communication in homeostasis

Nervous and endocrine systems at work, use electrical impulses or bloodborne hormones as info carriers

Three parts of communication to regulate variable

Receptor, control center, effector

Receptor

Responds to stimuli by sending info along afferent pathway to conrtol center

Control Center

Determines set point at which a variable is to be regulated, sends info to effector along efferent pathway

Effector

Carries out control centers response, enhances or reduces process to help

Negative Feedback Mechanisms

Variable changes in opposite direction of initial change, output shuts off or reduces intensity of original effect(body temp)

Positive feedback mechanims

Variable continues in same direction as initial change causing variable to go further away from original value, enhances intensity of original effect(pregnancy, blood clotting)

Homeostatic imbalance

Disturbance in homeostasis, typically happens when negative feedback mechanisms overwhelmed