15.1 The Principles of Homeostasis

Question 1

Definition of homeostasis?

Answer 1

The maintenance of a stable equillibrum in the conditions inside the body

Question 2

What are exampels of essential changes that internal environments need to monitor?

Answer 2

pH, core body temperature, concentrations of urea and sodium ions

Question 3

What are effectors?

Answer 3

The muscles or glands that react to monitor a stimulus to bring about a change in response to a stimulus

Question 4

What maintains dynamic equilibrium?

Answer 4

Receptors and effectors

Question 5

What does homeostasis depend on?

Answer 5

Sensory receptors detecting small changes in the body, and effectors working to restore the status quo

Question 6

Explain negative feedback systems

Answer 6

-Most feedback systems involve negative feedback
-A small change in one direction is detected by sensory receptors, effectors work to reverse the change and restore conditions
-Work to reverse the initial stimulus
eg. blood glucose control

Question 7

Explain positive feedback systems?

Answer 7

-Few positive feedback systems in the body
-A change in the internal environment is detected by sensory receptors, and effectors are stimulated to reinforce that change and increase the response
eg. blood clotting cascade , childbirth