Psychology: A Self-Teaching Guide

The Biology of Behavior: Is the Brain the Organ of Mental Life? 37

ical structure. Nonetheless, it is correct to say that to a large extent it is the activ-

ity of the hypothalamus that gives rise to the psychological processes Freud asso-

ciated with the id.

(a) One of the principal functions of the medulla is to regulate.

(b) The regulation of biological drives is associated to a large extent with what structure?

Answers: (a) respiration rate; (b) The hypothalamus.

The pituitary gland—one of the endocrine glands—is located toward the

front of the hypothalamus. It is usually called the “master gland” of the body.

This is because it plays a role in regulating the action of the other endocrine

glands. This will be discussed in the section on the endocrine system, pages

39–41.

Located just above the hypothalamus is the thalamus.One of the principal

functions of the thalamus is to act as a relay center for the sense organs. For exam-

ple, the optic nerves transmit visual information to a center in the thalamus. The

information is then relayed to a higher area in the cerebral cortex.

The cerebral cortexis the highest part of the brain. The word cortexmeans

“bark” or “covering.” The cortex, a large structure, does in fact sit on top of, or

cover, the lower regions of the brain. The cortex has a number of functions. It has

dedicated areas for vision, hearing, taste, touch, and smell. It has motor areas

Broca’s

area

Cortex

Thalamus

Hypothalamus

Medulla

Pons

Pituitary gland

Reticular

activating

system

Cerebellum

Brain stem

Cross section of the brain with selected structures.