Hormones

Question 1

Describe Homeostasis

Answer 1

The maintenance of the body’s internal environment (blood, tissues, fluids) within safe limits. This is controlled through negative feedback mechanisms which keep the body within tightly regulated physiological tolerance limits.

Question 2

Negative Feedback Mechanisms

Answer 2

A process that works to return a value (such as body temperature) to its “normal range.” This is done through the release of various hormones and neurotransmitters (requiring precise coordination between the nervous and endocrine systems.

Question 3

Give an Example of a Negative Feedback Mechanism

Answer 3

• The increase in Oxygen affinity within hemoglobin in response to increased physical activity (i.e. less oxygen concentration)
• The increased release of thyroxine and/or triiodothyronine in response to colder conditions (in order to increase metabolism and therefore body heat)
• The increased release of ADH by the anterior pituitary gland in order to increase water reabsorption through increasing the permeability of the Kidneys
  (other examples exist as well)