Text A. The nervous system

The scientists have found out that a constant flow of stimuli comes into the brain through the nerve fibers in the spinal cord. The spinal cord consists of millions of nerve fibers which transmit electrical information to the brain and back to each part of the body. The brain and the spinal cord are referred to as the Central Nervous System (CNS), while the nerves connecting the spinal cord to the body are referred to as the Peripheral Nervous System (PNC).

All parts of our body are connected by nerves. The nerve cells with their fibers make up the nervous system. The physiologists have not determined yet what happens when a nerve reacts to a stimulus but something travels from one nerve to another. The nerve cells send impulses to each other by means of the fibers at their ends. These fibers do not actually touch but are so close to each other that an impulse can travel from one fiber to another. Thus all nerve cells are connected with each other. So a stimulus from any part of the body can reach any other part of it. Physical agents become stimuli for nerve terminal by transferring from the external world to the nerve terminals.

The nervous cells of the cortex are the most delicate of all the cells of the human body. At the moment of tiredness of the cortical nervous cells the process of inhibition begins to act. This process does not allow new stimuli to pass to the tired areas of the brain. Though the stimuli continue to come to the brain the inhibited cortical cells do not react to them. To provide the smooth work of the brain the nervous cells must be well supplied with oxygen and feeding substances. And for this purpose any human being must have regular complete rest, i.e. sleep. Numerous investigations and experiments have shown that sleep is more necessary for the human being than food. One can live longer without food than without sleep.

TASKS

I. Combine the word in A with the word in B:

A constant spinal nerve external delicate human inhibition tired smooth feeding complete

B fibers rest areas substances body process flow cells cord work world

II. Translate the following word combinations:

постоянный поток раздражителей, нервные волокна в спинном мозге, передавать информацию, относиться к центральной нервной системе, реагировать на раздражитель, посылать сигналы друг другу, посредством волокон, фактически не соприкасаться, располагаться близко друг к другу, достигать другие части тела, нервные окончания, передавать сигналы из внешнего мира, нервные клетки коры головного мозга, самые хрупкие клетки, процесс торможения, проходить в уставшие области мозга, заторможенные клетки коры, обеспечивать гладкую работу, снабжать кислородом и питательными веществами, для этой цели, полный покой и сон

III. Express your agreement or disagreement with the following statements:

1. Stimuli come into the brain through the nerve fibers in the spinal cord.

2. The brain, the spinal cord and the nerves connecting the spinal cord to the body are

referred to as the Central Nervous System (CNS).

3. The physiologists have already determined what happens when a nerve reacts to a

stimulus.

4. These fibers do not actually touch but are so close to each other that an impulse

can travel from one fiber to another.

5. The process of inhibition does not allow new stimuli to pass to the tired areas of

the brain.

6. To provide the smooth work of the brain the nervous cells must be well supplied

with carbon dioxide.

7. Food is more necessary for the human being than sleep.

IV. Read text B without a dictionary and retell it: