Chapter 5 - Integumentary System Flashcards Preview

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Flashcards in Chapter 5 - Integumentary System Deck (74):
1

The organs of the integumentary system include?

skin & accessory structures including hair, nailsglands, blood vessels, muscles and nerves 
 

2

Dermatology

 

medical specialty for the diagnosis and treatment of disorders of the integumentary system. 

3

Skin 

aka?

location?

size?

subcutaneous membrane

covers body 

largest organ of body by surface area & weight

4

Skin 

area & weight

% of body weight

 

2 square metres (22 sq. feet)

4.5-5 kg (10-11 lb)

7% 

5

Skin thickness 

range & average

0.5-4.0 mm thick

thinnest on eyelids

thickest on heels 

average = 1-2 mm

6

SKIN

(2) major layers 

1) epidermis - outer, thinner layer; consists of epithelial tissue

2) dermis - inner, thicker layer

7

 


 

Beneath the dermis is?

 

 

subcutaneous (subQ) layer (also called hypodermis)

which attaches the skin to underlying tissues & organs. 

8

Important characteristics of the Epidermis

(2) 

- composed of keratinized stratified squamous epithelium 

contains 4 major types of cels 

9

Epidermis

(4) major types of cells 

1) keratinocytes

2) melanocytes

3) Langerhans cells

4) Merkel cells 

10

Major cells of the epidermis: Keratinocytes

 

 


 

(90% of the cells)

produce keratin (a tough fibrous protein that provides protection)

 

 

11

Major cells of the epidermis: Melanocytes

 


 

produce the pigment melanin that protects against damage by UV radiation

 

 

12

Major cells of the epidermis: Merkel cells 

involved in immune responses, arise from red bone marrow

13

major cells of the epidermis: Merkel cells

 


 

 function in sensation of touch along with adjacent tactile discs

 

 

14

 


 

The epidermis contains how many layers?

 

 four major layers (thin skin)

five major layers (thick skin) 

15

(5) layers of the epidermis

1) stratum corneum

2) stratum lucidum

3) stratum granulosum

4) stratum spinosum

5) stratum basale

16

Stratum Basale

aka stratum germinativum

deepest layer

continuous cell division occurs which produces all other layers 

 

 

17

Stratum Spinosum

 

8-10 layers of keratinocytes 

 

Langerham cells & projections of melanocytes present 

18

Stratum Lucidum

present only in thick skin 

 


 

(the skin of the fingertips, palms, and soles) 

 

 

19

Stratum granulosum

 


 

includes keratohyalin and lamellar granules 

consists of 3 to 5 layers of flattened keratinocytes undergoing apoptosis

marks transition between deeper metabolically active strata & dead cells of superficial strata

20

Stratum corneum

 

 


 

composed of many sublayers of flat, dead keratinocytes called corneocytes or squames that are continuously shed and replaced by cells from deeper strata;

constant friction can stimulate formation of a callus

 

 

21

Formation of a callus

constant friction 

22

Keratinization

 


 

the accumulation of more and more protective keratinoccurs as cells move from the deepest layer to surface layer 

 

 

23

 


 

Dandruff 

 

- an excess of keratinized cells shed from the scalp 

24

Important characteristics of the Dermis

 


 

composed of connective tissue containing collagen & elastic fibers

contains 2 layers 

 

 

25

(2) layers of the dermis

1) Papillary region

2) Reticular region 

26

Papillary region

consists of?

containing?

outer region, consists of areolar (soft) connective tissue containing thin collagen, elastic fibers, dermal papillae (including capillary loops), corpuscles of touch & free nerve endings 

 

 

27

Reticular region

deeper region, 

 


 

consists of dense irregular connective tissue

containing collagen and elastic fibers, adipose cells, hair follicles, nerves, sebaceous (oilglands, & sudoriferous (sweat) glands 

 

28

Striae 

stretch marks 

appear if the skin is stretched too much 

 

29

Lines of Cleavage

 


 

tension lines” in the skin indicate the predominant direction of underlying collagen fibers 

 

 

30

Epidermal ridges

function?

 


 

reflect contours of the underlying dermal papillae & form the basis for fingerprints (and footprints);

function: to increase firmness of grip by increasing friction. 

 


 

 

 

 

31

Subcutaneous (subQ) Layer

aka hypodermis\

not part of the skin but attaches to skin to underlying tissue 

32

The Subcutaneous Layer (and sometimes the dermis) contains?

lamellated (pacinian) corpuscles which detect external pressure applied to the skin

33

Accessory structures of the skin

include hair, skin glands nails

34

Hair 

aka?

(3) important functions 

Pili

1) protection

2) reduction of heat loss

3) sensing light tough

35

Hair 

composed of?

 

 


 

composed of dead, keratinized epidermal cells 

 

 

36

Hair consists of?

shaft - mostly projects above 

root - penetrates into dermis 

hair follicle - surrounds root of hair, made up of external & internal root sheath referred together as the epithelial root sheath 

dermal root sheath - dense dermis surrounding hair follicle

37

(3) different types of hair

1) lanugo 

2) vellus haira

3) terminal hairs

38

Lanugo

fine, non-pigmented downy hairs on body

39

Vellus hairs

replace lanugo 

short, fine, pale hairs

barely visible 

40

terminal hairs

long, course, heavily pigmented 

replace lanugo of eyebrows, eyelashes & scalf 

41

 


 

Hair color is determined by ?

the amount and type of melanin 

 

42

sebaceous (oil) glands

 connected to? 

secrete?

 

hair follicles 

oily substance called sebum

43

Sebum

an oily substance secreted by sebaceous glands to prevent dehydration of hair & skin and inhibit growth of certain bacteria 

44

(3) Types of Skin Glands

1) Sebaceous glands

2) Sudoriferous (sweat) glands 

3) Ceruminous glands

45

Sudoriferous (sweat) glands

(2) types

1) Eccrine (merocrine) sweat glands

2) Apocrine sweat glands 

46

Dermatoglyphics

the sutdy of the pattern of epidermal ridges

47

Eccrine (merocrine) sweat glands

function?

location?

 

helps to cool body by evaporating, & eliminates small amounts of wastes

distributed throughout skin of most regions especialy in skin of forehead, palms & soles 

- located mostly in deep dermis (sometimes in subQ layer

48

Apocrine sweat glands

located?

function?

located mainly in the skin of the axilla, groin, areolae
and bearded facial regions of adult males.

- their excretory ducts open into hair follicles 

- sweat secreted during emotional stress sexual excitement

49

Ceruminous Glands

what are they & where are they located?

function?

Modified sweat glands located in the external auditory (ear) canal

secretary portion lie in subQ layer, deep to sebaceous glands

Along with nearby sebaceous glands, they are involved in producing a waxy secretion called cerumen (earwax) which provides a sticky barrier that prevents entry of foreign 
bodies into ear canal.

50

Functions of Nails (3) 

1) protect distal end of digits 

2) provide support & counterpressure to palmar surface to enhance touch perception & manipulation

3) allow us to grasp & manipulate small objects + scratch & groom

51

What are Nails?

Where are they located?

 composed of hard, keratinized epidermal cells

located over dorsal surfaces of the ends of fingers & toes

52

Each nail consists of? (6) 

1) free edge 

2) transparent nail body 

3) whitish lunula 

4) eponychium (cuticle)

5) nail root

6) hyponychium (nail bed)

53

Free Edge of Nail

part of nail body that may extend past distal end of digit

54

Nail Body

aka?

(plate

transparent 

whitish lunula at its base 

comparable to stratum corneum of general epidermis 

 

55

Lunula

whitish crescent-shaped area at base of nail body (plate) 

white b/c vascular tissue underneath does not show through thickened region of epithelium 

56

Nail Root

embedded in a fold of skin 

57

Hyponychium

nail bed

thickened region of stratum corneum that secures nail to fingertip 

58

Eponychium 

cuticle

narrow band of epidermi

consists of stratum corneum

extends from & adheres to margin (lateral border) of nail wall 

- occupies proximal border

59

(2) major types of skin

1) thin (hairy) skin

2) thick (hairless) skin

60

thin (hairy) skin

covers what body regions?

 

all body regions EXCEPT palms, palmar surfaces of digits & soles

61

thick (hairless) skin

covers what body regions?

palms, palmar surfaces of digits & soles

62

Integumentary System - functions? (6) 

1) regulate body temp

2) store blood

3) protection from external environment

4) detect cutaneous sensations

5) excrete/absorb substances

6) synthesize vitamin D

63

(5) Hair functions

1) protection from injury (scalp)

2) protection from sun's rays

3) sensing light touch

4) decreasing heat loss

5) protect eyes from foreign particles 

64

Main Organ of the Integumentary System

skin

65

(3) associated structures in the Integumentary system

1) nails

2) hair

3) glands

66

Most superficial region of the dermis

papillary region

67

Most common connective tissue fibre found in the dermis 

 

collagen

68

Which layer of the integument releases the heat from the body via the blood vessels?

dermis

69

What material makes the epidermis tough?

 

keratin

70

Distinguish between Pacinian corpuscles, Meissner’s corpuscles and pain receptors in the skin 

 

Pacinian - located deep in dermis & hypodermis

- function to recieve sensation of deep pressure

Meissner's located just underneath epidermis

- function to percieve light tough

Pain Receptors in the dermis 

- respond to numerous pain stimuli

71

Approximately how long does it take for the epidermis to renew itself?

4-6 weeks

72

Piloerector Muscle

What is it?

What does it do?

 

smooth muscle that extends from superficial dermis to dermal root sheath 

contracts which pulls hair shaft perpendicular to skin surface (upright) 

 

73

What is the outermost portion of the hair?

cuticle

74