Bio Topic 1.3c Eval – Feedback Loops

In negative feedback systems, the response reverses a change in a controlled condition

In positive feedback systems, the response strengthens the change in a controlled condition.

State whether the following indicates negative or positive feedback:

________________________________ During childbirth stretching of the uterus
triggers the secretion of the hormone oxytocin, which stimulates uterine contractions
and speeds up labor.

In negative feedback systems, the response reverses a change in a controlled condition

In positive feedback systems, the response strengthens the change in a controlled condition.

State whether the following indicates negative or positive feedback:

________________________________ The walls of arteries stretch in the presence of
high blood pressure. Baroreceptors located in these walls also stretch and as a result, a
signal is sent to the brain which in turn slows down the body’s heart rate. This slows the
flow of blood through the arteries causing less pressure. As BP drops the baroreceptors
become flaccid and a signal is sent to speed up the heart rate.

In negative feedback systems, the response reverses a change in a controlled condition

In positive feedback systems, the response strengthens the change in a controlled condition.

State whether the following indicates negative or positive feedback:

________________________________ If the blood temperature falls too low,
specialized neurons in the hypothalamus of the brain sense the change and signals are
sent to the cutaneous arteries (those supplying the skin) to constrict them. Warm blood
is then retained deeper in the body and less heat is lost from the surface.

In negative feedback systems, the response reverses a change in a controlled condition

In positive feedback systems, the response strengthens the change in a controlled condition.

State whether the following indicates negative or positive feedback:

________________________________ Part of the complex biochemical pathway of
blood clotting is the production of an enzyme that forms the matrix of the blood clot.
This has a self- catalytic, or self-accelerating effect, so that once the clotting process
begins, it runs faster and faster until, ideally, bleeding stops.

In negative feedback systems, the response reverses a change in a controlled condition

In positive feedback systems, the response strengthens the change in a controlled condition.

State whether the following indicates negative or positive feedback:

________________________________ If blood temperature rises too high, specialized
neurons in the hypothalamus of the brain sense the change. These neurons signal other
nerve centers, which in turn send signals to the blood vessels of the skin. As these blood
vessels dilate, more blood flows close to the body surface and excess heat radiates from
the body.

Our bodies work to maintain homeostasis by keeping internal conditions within a certain range, and never allowing them to go too far to one side or the other.  A good example of this would be

How does the following home heating example provide an explanation of how feedback inhibition works?

The process in which a stimulus produces a response that opposes the original stimulus is called

How is the hypothalamus of the body like a home heating system? (Check all that apply)

Select all of the following ways in which the liver helps the body maintain homeostasis.