Text A. FIVE SENSES

A human being has a whole set of sense organs: organs of vision, hearing, taste, smell, touch, pain, heat, cold, kinesthesia, vestibular sensitivity. First five organs are considered principal. Special sense organs are located inside the body. Brain receives signals from outside and inside, analyzes them and by means of reflex processes and ensures a coordinated functioning of the whole organism.

Vision is one of the most delicate and complicated senses. It is known that a human being receives 90% of information through vision. About one-fourth of the brain is involved in visual processing, more than for any other sense. We can see because of light. Without light there would be no sight. Light reflects of things and then travels to our eyes. The retina has millions of cells that are very sensitive to light. One knows that when an image is formed in the eye upside down. This image is sent to the brain, which receives the message and turns the picture right side up again.

Hearing is considered the most important sense for humans. We can communicate with each other by receiving sounds and interpreting speech. The ear is made up of three parts. Sound travels through the ear in waves. They are received by the cup-shaped outer ear and directed into the middle ear where a thin membrane called eardrum is located. The vibrations hit the eardrum. Small hairs lining the cochlea also begin to vibrate and send a message to the auditory nerve which in its turn sends the message to the brain.

Taste and smell are separate senses with their own receptor organs but they are closely entwined because these two senses act together.

Tastes are detected by special structures – taste buds. It is known that every human has from 5,000 to 10,000 of them. Taste buds are located within papillae mainly on the tongue. It is estimated that each taste bud consists of about 100 receptors that respond to the four types of stimuli – sweet, salty, sour and bitter – from which all tastes are formed. A substance is tasted when chemicals in foods dissolve in saliva, enter the pores on the tongue and come into contact with taste buds. As a result signals are sent to cranial nerves and taste centres in the brain.

Smell receptors are located in the mucus membrane lining the nose. One knows that each cell has several cilia which are stimulated by odour molecules in the air. The impulses from stimulated cells come to the brain’s frontal lobe where smell perception is formed.

Touch is the sense by which we determine the characteristics of objects: size, shape, and texture. We do this through touch receptors in the skin.

TASKS

I. Translate the following words and word combinations:

зрение, вкус, обоняние, осязание, слух, чувствительность, боль, свет, речь, звук, сетчатка, внутреннее ухо, среднее ухо, барабанная перепонка, улитка уха, слуховой нерв, тонкая оболочка, вкусовой сосочек, бугорки языка, растворяться в слюне, шейные нервы, слизистая оболочка, молекулы запаха, передняя доля, размер и форма, кожа, весь организм

II. Complete the following sentences:

1. A human being has five main … organs.

2. Eyes are the organs of ….

3. Ears are the organs of ….

4. The nose is the organ of ….

5. The tongue is the organ of ….

6. Skin is the organ of ….

7. The main characteristics of objects are …, … and ….

8. All tastes are formed by four types of stimuli: …, …, … and ….

III. Fill in the gaps with the necessary prepositions:

1. A human being receives 90% of information … vision.

2. There would be no sight … light.

3. The retina has millions … cells.

4. These cells are very sensitive … light.

5. People can communicate … each other.

6. Taste buds are located … the tongue.

7. Chemicals in food come … contact … taste buds.

8. Cilia in the nose are stimulated … odour molecules.

9. Brain receives signals … outside and inside.

IV. Translate the following sentences:

1. Известно, что примерно ¼ мозга вовлечена в процесс зрения.

2. Считается, что слух является самым важным чувством.

3. Установлено, что вкус и обоняние действуют вместе.

4. Говорят, что у каждого человека от 5000 до 10000 вкусовых сосочков на

языке.

5. Подсчитано, что каждый вкусовой сосочек состоит примерно из 100

рецепторов.

6. Обнаружено, что восприятие запаха формируется в передней доле мозга.

V. Find Russian equivalents to the following English idioms:

1. Out of sight – out of mind. 2. Tastes differ. 3. I’m all ears. 4. Touch wood. 5. I can’t believe my ears. 6. It is in one ear and out of the other.

Постучите по дереву. В одно ухо влетает, в другое вылетает. С глаз долой – из сердца вон. О вкусах не спорят. Я весь – внимание. Не верю своим ушам.

VI. Answer the following questions:

1. What sense organs do we have?

2. Which sense is the most complicated? Why?

3. What are the organs of vision?

4. How is the image formed in the eye?

5. Which sense is the most important for humans?

6. What are the organs of hearing?

7. What do the organs of hearing consist of?

8. What structures are tastes detected by?

9. What are the types of taste stimuli?

10. Describe the process of tasting.

11. Where are the receptors for smell located?

12. Where is smell perception formed?

13. What is touch?

14. What are the main characteristics of objects?

15. How do we do touch?