Homeostasis and Basic Human Chemistry

Humans need several factors for survival that must be in the appropriate amounts; too much or too little can be harmful what are the 5?

•  nutrients

•  Oxygen

•  Water

•  Normal body temperature

•  Appropriate atmospheric pressure

Homeostasis

the condition of maintaining the body’s internal environment in a relative constant state (steady temp, blood pressure, glucose levels, etc….), within limits.

Homeostatic imbalance

anything that disturbs or alters the balance of the internal environment

(so homeostasis is a ceaseless process of activities in response to stresses in an attempt to maintain equilibrium)

Homeostatic control mechanism

“mechanisms” which are generally “self-regulating” and serve to maintain the homeostatic “steady state.”

Regardless of the factor or event being regulated what are the 3 homeostatic control mechanisms that work together in order

1. receptor

2. control center

3. effector

Negative Feedback

• The output shuts off the original effect of the stimulus or reduces its intensity.

•  A change in one direction results in a feedback that causes a change or adjustment in the opposite direction.

Positive Feedback

• The result or response enhances the original stimulus so that the response is accelerated.

ex:

• Blood clotting

• Labor contractions

• orgasm

•  A change in one direction accelerates more change in the same direction.