Read the text and fill in the table

The skin

The skin is the largest organ of the body. It is composed of two main layers: the dermis with a rich network of blood vessels and nerves and epidermis, a protective outer layer without blood vessels. The cells of the surface layer are non-living and require no supply of blood for nourishment. The cells at the base of the epidermis are alive and are constantly growing. The epidermis is thinner than the dermis and is made up of several layers of different kinds of cells. The number of cells varies in different parts of the body; the greatest number is in the palms of the hands and soles of the feet, where the skin is the thickest. An adult’s skin weighs about 6.6 pounds.

Skin colour is caused by the presence of melanin, a pigment that is produced by special cells in the epidermis. The amount of melanin determines the differences in skin colours among the different races. Melanin makes an Indian brownish-red, a Chinese yellow, and an African black. The skin of the white race contains the least melanin pigment.

Albinism is a genetic disorder in which there is a lack of melanin. Albinism affects the hair, skin, and eyes. The hair is usually white, the skin extremely pale, and the eyes may range in color from blue to reddish, violet, hazel, or brown. Patients must avoid skin damage from the sun.

Figure 7. Albinism

 

Skin layer	Contains blood vessels and nerves	Contains melanin	Comparison in thickness
	-	+	thinner
	+	-	thicker

Answer the questions:

1. Which layer of the skin contains blood vessels?

2. Which layer is thicker?

3. What kinds of cells – living or non-living – are in the epidermis?

4. What amount of melanin – the least or the most – does the skin of the white race contain?

5. What is albinism?

 

Open the brackets and translate the sentences

1. The amount of melanin (to determine) the differences in skin colours.

2. The skin (to compose) of two layers.

3. The dermis (to make up) of several layers of cells.

4. The thickness of the outer layer (to vary).

5. The dermis (to contain) blood vessels and nerves.

6. The cells of the epidermis (to require) no supply of blood.

7. Melanin (to produce) by special cells-in the dermis.

8. The presence of melanin (to cause) skin colour.

 

Make up sentences

Подлежащее (термин)	Глагол- связка	Именная часть сказуемого (с сопутствующими словами)
1. The epidermis	is/are	the organs that filter the blood.
2. A bone		the part of the body which has eyes, mouth, and brain in it.
3. A cell		the bony box that encloses the brain.
4. The eyes		the tiny unit of the living tissue.
5. The heart		the muscular organ that pumps the blood.
6. The kidneys		the organs of sight.
7. The skull		the outer layer of the skin.
8. The head		a piece of the skeleton.

Read the text and name the functions of skin

    The skin performs many vital functions:

 1. Protection of the underlying organs and tissues against injury and fluid loss.

 2. The skin is a sensory organ with many cells that are sensitive to pain, pressure, temperature, and touch and relay of this information to the nervous system.

 3. Maintenance of normal body temperature.

 4. Melanin production, to protect underlying tissue from ultraviolet (UV) radiation.

5. Keratin production, to serve as water repellant and to protect against abrasion.

6. Vitamin D3 synthesis.

7. Helps to excrete body wastes in the form of perspiration.

 

Make up sentences

The function of	the skin	is	to protect the brain.
	the skull		to pump blood through the body.
	the bones		to provide anchorage for the muscles.
	the heart		to maintain the temperature of the body.
	the blood		to transport oxygen and nutrients to the organs.

Blood Components

Figure 8. The composition of whole blood.

1. Read and translate the text:

Blood Components

Normally, 7-8% of human body weight is from blood. In adults, this amounts to 4.5-6 quarts of blood. This essential fluid carries out the functions of transporting oxygen and nutrients to our cells and getting rid of carbon dioxide, ammonia, and other waste products. In addition, it plays a vital role in our immune system and in maintaining a relatively constant body temperature. Blood is a highly specialized tissue composed of more than 4,000 different kinds of components. Four of the most important ones are red cells, white cells, platelets and plasma.

 

 

Red Cells

Red cells, or erythrocytes, are relatively large microscopic cells without nucleus. Red cells normally make up 40-50% of the total blood volume. They transport oxygen from the lungs to all of the living tissues of the body and carry away carbon dioxide. The red cells are produced continuously in our bone marrow. Hemoglobin is the gas transporting protein molecule that makes up 95% of a red cell. Each red cell has about 270,000,000 iron-rich hemoglobin molecules.

White Cells

White Cells protect the body against bacteria, viruses, parasites, cancer cells, and toxins. Leukocytes exist in variable numbers and make up a very small part of blood's volume – normally only about 1% in healthy people. Leukocytes are not limited to blood. They occur elsewhere in the body as well, most notably in the spleen, liver, and lymph glands. Most are produced in our red bone marrow.

Platelets

Platelets, or thrombocytes, are small cell fragments without nucleus. They live for about 10 days. Approximately one third of the body’s platelets are held in the spleen and other vascular organs instead of in the bloodstream. The function of platelets is primarily to block injuries to damaged blood vessels and to start forming blood clots. They accomplish this by sticking to the damaged site and forming a temporary plug to seal the broken area.  Recent research has shown that platelets also help fight infections by releasing proteins that kill invading bacteria and some other microorganisms. In addition, platelets stimulate the immune system. Like the red and white blood cells, platelets are produced in bone marrow from stem cells.

Plasma

Plasma is the relatively clear, yellow liquid made up of 90% water. It also contains amino acids, carbohydrates, lipids, proteins, hormones, electrolytes, vitamins, and waste materials. As the heart pumps blood to cells throughout the body, plasma brings nourishment to them and removes the waste products of metabolism.

 

Use English equivalents

Необходимая жидкость, транспортировка кислорода и питательных веществ, выведение углекислого газа, играть жизненно важную роль, постоянная температура тела, различные виды компонентов, объем крови, костный мозг, газотранспортная белковая молекула, богатая железом, защищает тело, непостоянное количество, здоровый человек, лимфатические железы, находятся в селезенке, кровоток, блокировать повреждения, сгустки крови, стенки сосудов, прикрепляться к поврежденному месту, временная закупорка, бороться с инфекциями, убивать вторгающиеся бактерии, стимулировать иммунную систему, прозрачная желтая жидкость, удаляет продукты метаболизма.

 

3. Replace with synonyms the underlined words 1. The function of erythrocytes is to carry oxygen and carbon dioxide.2. Thrombocytes are tiny particles of the blood.3. Leuccocytes differ in size and shape.4. White cells are situated not only in the bloodstream.5. Plasma includes different components.6. The function of platelets is first of all to block injuries to damaged blood vessels.

4. Answer the questions: