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Anatomy & Physiology > Intergumentary System > Flashcards

Flashcards in Intergumentary System Deck (59):
0

What are the functions of the skin?

Protect underlying structures from injury & invasion by microbes.
Protect against infection-mechanical barrier & sebum (oil) inhibits growth of certain bacteria.
Protects against harmful effects of the sun.
Hair protects head from injury & the sun.
Contains sensory nerve endings for pain, temperature & touch.
Regulates body temperature.
Excretion of waste products-salts, certain foods (garlic).
Vitamin D synthesis.
Prevents excessive water loss or entry.

1

What type of epithelium is the epidermis?

Stratified squamous epithelium.

2

How many laters does the epidermis have?

5 main layers

3

What is the name of the base layer?

Stratum basale

4

What does the epidermis consist of?

Dead cells filled with keratin & a fatty matrix

5

What are the properties of the epidermis?

Waterproof, abrasion-resistant barrier.
Has no blood supply.

6

What type of epithelia is the stratum basale?

Single layer of cuboidal or columnar cells

7

What does the stratum basale separate?

Epidermis & dermis

8

What type of cells is the stratum basale?

Germinal cells

9

What does the stratum basale do?

Divides rapidly to provide a continuous source of new skin cells.

10

What are new skin cells called?

Keratinocytes

11

What do keratinocytes do?

Migrate up towards the surface changing characteristics until they are shed.

12

What other than keratinocytes is found in the epidermis?

Melanocytes

13

What do melanocytes contain?

Melanin

14

If uv light is actioned on a substance called 7-dehydrocholestrol. What is produced?

Vitamin d

15

What is the purpose of the dermis?

Strong, stretchy layer that helps hold the body together.

16

What type of tissue is the dermis & what does it contain?

Dense connective tissue containing collagen & elastic fibres.

17

What is the difference of the dermis between males & females?

Thinner in females.

18

What is located in the dermis?

Structures that enable the skin to carry out many functions.

19

Dermis contains a fibrous protein arranged in bundles that lies mostly parallel with the skins surface. What is this called?

Collagen

20

What gives the dermis flexibility?

Elastic fibres

21

What do ruptures elastic fibres cause?

Stretch marks

22

What is the clinical term for stretch marks?

Striae

23

What in the dermis decreases with age?

Number of elastic fibres

24

Sunlight may damage fibres in the dermis regardless of the presence of what?

Melanin

25

What are intertwined in the dermis?

Blood vessels, lymph vessels & nerve endings.

26

What causes the natural folds & creases of the skin?

Langar lines (cleavage lines)

27

What does the dermis do to help prevent separation of dermis & epidermis?

Forms ridges & hollows

28

What is the hypodermis?

Adipose tissue (adipocytes) & loose connective tissue

29

What is the hypodermis responsible for?

Fat distribution ( gives body shape), attaches skin to underlying tissue, provides mechanical support, acts as an energy store

30

What are hairs?

Down growth of epidermal cells into the dermis.
Formed by multiplication of cells at bulb.

31

Hair grow from follicles at their base. What is this cluster of cells called?

Bulb

32

What is the process in which hairs are made?

Cells are pushed upward away from source of nutrition, they die & are then keratinised.

33

What is the name of the muscle that causes piloerection?

Arrector pili

34

How many types of sweat gland are there in the skin?

3

35

What is the most numerous type of swear gland?

Eccrine glands

36

Where are ecceine glands most abundant?

Palms of hands, soles of feet & forehead.

37

What do eccrine glands secrete?

Sweat (salt solution)

38

What is the purpose of sweat?

Allows the skin to cool as it evaporates.

39

How much sweat is it possible to loose for short periods during exercise or hot weather?

6ltr/hr

40

How much do we sweat in cold conditions?

500ml per day (insensible water loss)

41

What gland is larger than eccrine & most numerous in the axillae, genital area & around nipples?

Apocrine gland

42

What does apocrine sweat contain that makes it thicker & stickier?

Protein, fats & other substances

43

What breaks down sweat on the surface of the skin?

Bacteria

44

What can the bacteria breakdown of sweat cause?

Unpleasant odour / body odour

45

When do apocrine glands begin to function

Puberty

46

What glands are found everywhere except hands & feet, neck, scalp & back?

Sebacious (oil) glands

47

What do sebacious glands secrete?

Sebum

48

What does sebum contain?

Fatty substance containing cholesterol & other lipids.

49

What do sebacious glands secrete onto?

Hair follicles or directly onto the skin.

50

Where would you find ceruminous glands?

Ear canal

51

What do ceruminous glands secrete?

Ear wax

52

The skin contains receptors that can detect what?

Pressure, stretch, vibration, tickle, itch, pain, temperature, pressure

53

What nerves are found in the skin?

Pacinian corpuscle, ruffinis corpuscle, free nerve endings, meissners corpuscle, merkel discs

54

What is the purpose of the cutaneous circulation?

Skin can contribute to control of body temperature.
Arterioles carry oxygenated blood into dermis.
Capillaries (capillary loop) drain into network of small veins within dermis.
Larger veins carry deoxygenated blood away

55

The ears, nose, fingertips & lips have additional blood vessels known as?

Arterio-venous (av) anastomoses

56

The epidermis has no direct blood supply. So how does it receive its oxygen & nutrients?

Diffusion

57

What is vasoconstriction?

Narrowing of the blood vessels

58

What is vasodilation?

Widening of the blood vessels