4. Dermis



Dermis is a connective tissue layer of mesodermal origin subjacent the epidermis and its basement membrane. The dermis-epidermal junction, especially in thick skin, is characterized by numerous papillary interdigitations of the dermal connective tissue and epidermal epithelium. This increases the surface area of attachment and brings blood vessels in closer proximity to the epidermal cells. The epidemis, like epithelia in general, is devoid of blood vessel. Histologically, der-mis consists of two identifiable regions.

Papillary layer, associated principally with the dermal papillae, is the most superficial layer. It consists of a loosely packed, irregular meshwork of collagen fibrils that contain fine blood vessels and nerve endings.

Reticular layer is the deeper dermal layer and consists of coarse collagen bundles intertwined with elastic fibers in a gel matrix. This layer is a typical dense irregular connective tissue.

HYPODERMIS: this layer of loose vascular connective tissue is infiltrated with adipocytes and corresponds to the superficial fascia of gross anatomy. However, since it contains the deepest portions of the cutaneous glands and hairs, it is also an important part of the skin. The hypodermis fastens the skin to underlying muscles and other structures.


New words

dermis

connective

membrane

junction

to be characterized by -

numerous

to increase

surface

area

bring

to consists of

to contain

collagen


, .

E. g. This is a book. This is a good book.


,

1. We have large family.

2. My granny often tells us long interesting stories.

3. My father is engineer. He works at factory factory is large.

4. My mother is doctor. She works at large. hospital. She is at work now.

5. My aunt is teacher. She works at school school is good. My aunt is not at school now.

6. She is at home. She is drinking tea and eating jam jam is sweet.

7. I am at home, too. I am drinking tea and eating sandwich sandwich is tasty.

8. My sister is at school. She is pupil.

9. My cousin has big black cat. My cousin's cat has two kittens.

10 cat likes milk kittens like milk, too.

11. I am engineer.

12. My son is pupil.

13. He is good pupil.

14. This is house.

15. This is my pencil.

16. You have some pen cils, but I have no pencil. Give me pencil, please.

17. I like your beautiful flower. Give me flower, please.

18. My mother is at home. She is reading interesting book.

19. My father is not at home. He is at work. He is doctor.

20. He is good doctor. He works at hospital hospital is large.


Answer the questions.

1. What is dermis?

2. What does dermis consist of?

3. What is the dermis-epidermal junction characterized by?

4. What increases the surface area of attachment?

5. What is the epidemis devoid of?

6. What is principally associated with the dermal papillae?

7. What is reticular layer consists of?

8. What is typical dense irregular connective tissue?

9. What does epidermis consists of?

10. What contains the deepest portions of the cutaneous glands?


Make the sentences of your own using the new words (10 sentences).

Find the definite and indefinite articles in the text.

Find one word, which is a little bit different in meaning from others ( , ):

1) a) skin; b) knife; c) dermis;

2) a) fire; b) membrane; c) cell;

3) a) connective; b) collagen; c) table;

4) a) nose; b) book; c) mouth;

5) a) ear; b) throat; c) skirt.










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