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Flashcards in Chapter 5 Deck (65):
1

Cells of the Epidermis

-Keratinocytes
-Langerhans Cells
-Merkel Cells
-Melanocytes

2

Keratinocytes

-Composes more than 90% of epidermal cells
-Makes keratin

3

Keratin

-Gives skin its strength and flexibility

4

Langerhans Cells

-Immune cells
-Phagocytose foreign particle, and initiates an immune response if necessary

5

Merkel Cells

-Touch receptors

6

Melanocytes

-Make melanin
-Protects us from UV rays

7

Epidermal Layers

-Stratum Basale
-Stratum Spinosum
-Stratum Granulosum
-Stratum Lucidum
-Stratum Corneum

8

Stratum Basale

-Deepest epidermal layer
-Mitotic layer
-Melanocytes and Merkel cells found in this layer

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Stratum Spinosum

-Some mitosis
-Langerhans cells found in this layer

10

Stratum Granulosum

-Keratinization occurs here

11

Keratinization

-Granules containing keratin begin to form

12

Stratum Lucidum

-Only in thick skin
-Thin clear layer of dead keratinocytes between the stratum corneum and the stratum granulosum

13

Stratum Corneum

-Most superficial layer of the skin
-20-30 layers of dead keratinocytes
-Protects from abrasion, outside environment, water loss

14

Layers of the Dermis

-Papillary Layer
-Reticular Layer

15

Papillary Layer

-Most superficial layer (20% total thickness)
-Areolar tissue
-Dermal Papillae (fingerprints)
-Meissner Corpuscle (light touch receptor)

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Reticular Layer

-Deep layer (80% total Dermis thickness)
-Dense irregular

17

Cleavage Lines

-Natural separations in the dermis caused by bundling collagen fibers i the reticular layer

18

What determines our skin color?

-Melanocytes
-Melanin

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Melanocytes

-Make melanin

20

Melanin

-The pigment that dictates our skin color, and protects us from UV radiation
-Production is determined by genetics and UV exposure

21

Albino

-Lack the enzyme responsible for melanin production

22

Why is UV radiation bad?

-Causes DNA damage (Leads to skin cancer)
-Breaks down elastin (Leads to wrinkles)
-Depresses the immune system (More susceptible to infection)

23

Other skin pigments

-Carotene
-Hemoglobin

24

Carotene

-Found in stratum corneum
-Yellowish pigment

25

Hemoglobin

-Found in red blood cells
-Gives skin a pinkish color when it is oxygenated

26

Skin color changes

-Redness
-Pallor (whitening of skin)
-Cyanosis
-Jaundice

27

Redness of the skin

-Dilation of superficial blood vessels
-Caused by blushing, drinking, fever, inflammation, allergy, high blood pressure

28

Pallor

-Whitening of the skin
-Caused by fear, anger, anemia, low blood pressure

29

Cyanosis

-Bluish tinged skin
-Caused by lack of oxygen in skin
-Could indicate abnormal heart or lung function

30

Jaundice

-Yellow tinged skin
-Caused by bilirubin in the blood (breakdown product of RBC)
-Could indicate liver function

31

Appendages of the skin

-Hair
-Sweat glands
-Oil glands

32

Hair

-Arrector pili-smooth muscle (contracts in response to chilled body surfaces or fear)
-Germinal matrix
-Papilla

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Germinal matrix

-Epithelial cells undergoing mitosis
-Responsible for new hair growth

34

Papilla

-Dermal tissue
-Provides nourishment

35

Growth Cycle of Hair

-Active Growth Phase
-Resting Phase

36

Active Growth Phase

-Hair matrix cells undergo mitosis
-Scalp: 6-10 Years
-Eyebrows: 3-4 months

37

Resting Phase

-Hair matrix cells die, follicle shrivels
-Scalp: 2-3 months

38

What affects hair growth?

-Hormones
-Nutrition
-Smoking

39

Hormones

-Testosterone
-Estrogen (Increases growth period)

40

Nutrition

-Proteins, Vitamins, Omega-3 fatty acids promote hair growth
-Soft drinks, processed foods, and sugar impedes hair growth

41

Hair Thinning

-After 40 folicular atrophy
-Hairs are shed faster than they are replaced

42

Male pattern baldness (MPB)

-Extremely shortened hair
-Inherited

43

Rogaine

Minoxidil

44

Sudoriferous (Sweat) Glands

Two types
-Eccrine
-Apocrine

45

Eccrine Gland

-Most numerous
-Found all over the body
-High expression on palms, soles of feet, forehead
-Secrete sweat:
-99% water
-NaCl, Antibodies, Urea, Uric Acid, Lactic Acid

46

Thermoregulation

-Eccrine glands are important for this
-Regulation of body temp

47

Evaporation

-Cooling process

48

Convection

-Increases evaporation by movement of air

49

Conduction

-Transfer of heat to substances in contact with the body

50

Apocrine (Sweat) Gland

-Found in axillary regions and anogenital areas
-Larger than eccrine glands and found deeper in dermis or hypodermis
-Secrete sweat into a hair follicle
-Begins functions at puberty
Activated by estrogen and testosterone

51

Difference between Apocrine glands and eccrine glands

-Apocrine sweat also contains fat and proteins
-Odorless

52

Sebacous Gland

-Found all over the body
Except palms and soles
-Usually attached to hair follicle
-Secretes sebum (oil)
-Softens/lubricates hair and skin
-Bactericidal Properties

53

Whitehead

-Pore is clogged and sebum accumulates
-Pore clogged with sebum and dead skin cells

54

Blackhead

-Pore is clogged and sebum accumulates
-Sebum becomes oxidized

55

Infection

-Papules (Zits)
-Inflamed Acne

56

Papules (Zits)

-Bacteria grows, pores become irritated

57

Inflamed acne

-Irritation causes further inflammation and infection

58

Ceruminous Glands

-Located in the external ear canal
-Make earwax

59

Mammary Glands

-Secrete milk

60

Functions of the Integumentary

-Protection
-Excretion
-Thermoregulation
-Sensation
-Vitamin D Synthesis

61

Protection

-Biological
Langerhans Cells
-Physical
Waterproofing glycolipids in the epidermis
Melanin protects from UV layers
-Chemical
Acid Mantle (low pH)
Sebum-Bactericidal

62

Excretion

-Water loss through sweat
-Waste (Urea, Uric Acid, Lactic acid) loss also through sweat

63

Thermoregulation

-Evaporation of sweat from the skin dissipates heat, cooling the body
-Insensible perspiration (500mL/day)
-Sensible perspiration
Occurs when body temp rises. Up to 12L/day
Prevents overheating

64

Sensation

-Meissner Corpuscle (light pressure)
-Pacinian Corpuscle (Deep pressure)
-Free Nerve Endings (pain, temperature)

65

Vitamin D Synthesis

-Vitamin D increases calcium absorption in intestines
-Increases bone mineralization