Unit VII. Body systems: the nervous system

MODULE I. LEARNING TO READ AND UNDERSTAND A SPECIAL TEXT

Task 1.

Can you explain the following statement? The body is like an airplane and the brain is like a pilot.

Task 2.

A. Read and translate the following international words:

calorie, creative, dominant, exclusive, extremely, logical, music, plastic, reaction.

B. In the box, put the words, which name certain periods of human development, in the logical order:

adult, baby, child, fetus, infant, toddler

Task 3. You are going to read a text about an extremely important part of the human body.

A. Look through the text and choose the correct heading for it from the list of headings below:

• A small part of the human body

• Brain functions

• The human brain

• A child's brain

• The structure of the brain

The brain of a human being is only a small part of the human body, but it is an extremely important one. It controls all the activities and reactions of the body. The brain cells (neurons) are active day and night, even during sleep, and use up energy at a high rate. The brain accounts for about 3 per cent of body weight, but it uses 20 per cent of all oxygen we breathe, 20 per cent of the calories in the food we eat, and about 15 per cent of the body's blood supply. Brain functions are divided between the two hemispheres: in most people, the right hemisphere is the creative side; it "does" spatial perception, art and music. The left hemisphere is usually the dominant side where control of language and logical thought reside. Each hemisphere of the brain interacts primarily with one half of the body, but for reasons that are unclear, the connections are crossed: the left side of the brain interacts with the right side

of the body, and vice versa. Human brains are at their most plastic during infancy. An entire hemisphere from a child's brain can be removed and the other will take on the tasks of both. It will even manage to develop functions that are usually exclusive to its other half. As we age, however, brain functions become more rigid and more distinctive. The language areas of the brain become active about eighteen months after birth. The one that confers understanding matures before the one that produces speech, so there is a short time when toddlers understand more than they can say. The left hemisphere of the brain normally completes its development later than the right.