Question

1. a person is stuck in their car during a bitterly cold blizzard. their body responds to the cold by

a. increasing the blood to the hands and feet
b. becoming lethargic to conserve heat
c. breaking down stored energy
d. significantly increasing blood oxygen levels

1. after you eat lunch, nerve cells in your stomach respond to the distension (the stimulus) resulting from the food. they relay this information to

a. a control center
b. a set point
c. effectors
d. sensors

1. stimulation of the heat - loss center causes

a. blood vessels in the skin to constrict
b. breathing to become slow and shallow
c. sweat glands to increase their output
d. all of the above

Explanation:

1. When the body is cold, it breaks down stored energy (such as fat) to generate heat. Increasing blood to hands and feet would lose heat, becoming lethargic is not the main heat - conservation mechanism, and there is no significant increase in blood oxygen levels related to cold response.
2. In a feedback control system in the body, nerve cells sensing a stimulus (like stomach distension) relay information to a control center, which then makes decisions. A set - point is a target value, effectors carry out responses, and sensors are the initial detectors (nerve cells here are sensors relaying to a control center).
3. Stimulation of the heat - loss center causes blood vessels in the skin to dilate (not constrict), breathing may change in a way to release heat, and sweat glands increase their output to cool the body through evaporation.

Answer:

1. c
2. a
3. c