Homeostasis

Integrator

body part that interprets the sensors information and sends messages to the effector
brain

Error Signal

deviation between the actual value of the variable and the set point value (negative feedback part of the loop)

Steady State

parameter constant over a period of time
may or may not be homeostatically regulated.

Threshold

deviation between the desired and actual value of the variable
(decided by integrator)

Homeostasis

the maintenance of an internal environment that is distinct from the external environment and is protected against change
dynamic process

French physiologist, mid

1800s

Sensor

body part that senses/detects the regulated variable

Integrator

body part that interprets the sensors information and sends messages to the effector (ex

Effector

body part that affects/changes the regulated variable

Set Point

desired range for regulated value

Threshold

deviation between the desired and actual value of the variable (decided by integrator) (ex

Error Signal

deviation between the actual value of the variable and the set point value (negative feedback part of the loop) (ex

Steady-State

parameter constant over a period of time; may or may not be homeostatically regulated

Homeostatic Stressors

exercise, temperature, high altitude, high pressure, high salinity, injury, disease, mental stress, diet

Exercise as a Homeostatic Stressor

temperature regulation
glucose increases for energy
Pressure of O2
decrease in pH (lactic acid)
Pressure CO2

Human Changes in Set Point

pregnancy
increased body temp., increase fluid volume, increase arterial O2

endurance exercise

temperature
fighting of sickness/fever, hypothermia

Fever Cycle

1. Infection
2. Chill- Phase (set point increases)
3. Fever breaks (set point decreases)
4. Restoration and normal thermoregulation

Steady- State

constant over a period of time

Diabetes

disease where the body does not produce or respond to insulin resulting in elevated blood glucose levels

Type 1 Diabetes

pancreas doesn't produce insulin

Type 2 Diabetes

body doesn't respond to insulin

Negative Feedback Loop

a process in which a change from the normal range of function elicits a response that opposes or resists that change

Claude Bernard

noticed homeostasis

Walter Cannon

coined term homeostasis

Dr. Donald Jackson

set points can change depending on the circumstances
ex. hibernation