15.1 The Principles of Homeostatis

Question 1

What is homeostasis?

Answer 1

The body maintains dynamic equilibrium with small fluctuations, through monitoring small changes in internal environment and responding appropriately.

Question 2

Is positive feedback part of homeostasis?

Answer 2

No

Question 3

Why is positive feedback not part of homeostasis?

Answer 3

It reinforces the change and increases the original response, meaning the body conditions get further away form the norm.

Question 4

Describe the blood clotting cascade.

Answer 4

A blood vessel is damaged.
Platelets to damaged region.
Clotting is initiated.
Which attracts more platelets.

Question 5

Is the blood clotting cascade negative or positive feedback?

Answer 5

Positive

Question 6

Are contractions during labour an example of positive or negative feedback?

Answer 6

Positive.

Question 7

Name three things maintained by negative feedback in the body.

Answer 7

Temperature
Blood glucose concentration
Salt and water content of blood (osmoregulation)

Question 8

Describe what happens when the head of the baby pushes against the cervix.

Answer 8

(Manoreceptors in the uterus detect stimuli)
Oxytocin is produced
Oxytocin stimulated uterus to contract
Baby’s head is pushed even harder against cervix
Etc. (back to start)
This continues until baby is born