12.1

Question 1

Homeostasis

Answer 1

The process by which the body’s substances
and characteristics (such as temperature
and glucose level) are maintained at their
optimal level.

Question 2

Ingestive behaviour

Answer 2

Eating or drinking

Question 3

System variable

Answer 3

A variable that is
controlled by a regulatory mechanism, for
example, temperature in a heating system.

Question 4

Set point

Answer 4

The optimal value of the system variable in a regulatory mechanism.

Question 5

Detector

Answer 5

In a regulatory process, a
mechanism that signals when the system
variable deviates from its set point.

Question 6

Correctional mechanism

Answer 6

In a
regulatory process, the mechanism that
is capable of changing the value of the
system variable.

Question 7

Negative feedback

Answer 7

A process whereby
the effect produced by an action serves
to diminish or terminate that action;
a characteristic of regulatory systems.

Question 8

Satiety mechanism

Answer 8

A brain mechanism
that causes cessation of hunger or thirst,
produced by adequate and available
supplies of nutrients or water.

Question 9

Intracellular fluid

Answer 9

The fluid contained within cells

Question 10

Extracellular fluid

Answer 10

All body fluids
outside cells: interstitial fluid, blood
plasma, and cerebrospinal fluid.

Question 11

Intravascular fluid

Answer 11

The fluid formed found within the blood vessels