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Flashcards in Skin Deck (80):
1

What kind of epithelium is the epidermis?

stratified squamous

2

Basal layer of the epidermis

stratum basale (germinativum)

3

What type of cells make up the stratum basale layer?

single layer of columnar or cuboidal shaped cells - which undergo mitotic division

4

Daughter cells of the stratum basale either become ... or function as...

keratinocyes or function as stem cells

5

How do cells adhere to the basal lamina?

by hemidesmosomes and anchoring filaments (type VII collagen)

6

What is the layer superior to the stratum basale?

stratum spinosum

7

What types of cells is the stratum spinosum composed of?

multiple layers of polyhedral-shaped cells, joined to one another by numerous desmosomes

8

What in the stratum spinosum gives it the appearance of "spiny"?

desomosomes and their associated monofilaments as intracellular bridges

9

What occurs in the deepest portion of stratum spinosum?

Miosis

10

Synthesis of membrane-bounded membrane-coating granules called ...., begins in the stratum spinosum.

lamellar bodies

11

What does the lipid-rich material in the lamellar bodies do upon exocytosis in the stratum granulosum?

coats the cell membrane of the keratinizing epithelium, making it relatively impermeable to water

12

The stratum granulosum is so named because of the appearance of dense, retractile, basophilic ... in the cytoplasm

keratohyalin granules

13

The strong basophilia of the stratum granulosum reflects the presence of RNA and acidic proteins which are precursors to the protein...

filaggrin

14

Filaggrin is a protein which binds what? and in what process?

binds tonofilaments together in a process of keratinization. Desmosomes continue to bind cells together.

15

In the stratum granulosum cells are becoming ...

flattened

16

The stratum lucidum is recognized in thick epidermis by its ...

transparent refractile appearance

17

What has disappeared in the stratum lucidum?

nuclei and organelles

18

The thickest and most superficial stratum of thick epidermis

Stratum corneum

19

What is the stratum corneum composed of?

scale-like, desiccated remnants of keratinocytes

20

The cell membranes of the stratum corneum are thickened by the ...

lipid-rich compound released from membrane-coating granules

21

In the stratum corner the interior of the keratinized cell remnants is completely filled with filamentous material embedded in a dense matrix. Presumably this represents the ...

coalescence of the tonofilaments and keratohyaline granules

22

In the thin epidermis the stratum corneum appears ...

thin and net-like rather than thick and compacted

23

In the thin epidermis what layer is not seen?

stratum lucidum

24

Keratinocytes of what layers typically contain the pigment melanin?

basal and spinous layers

25

Where are the cell bodies of melanocytes located?

basal layer

26

Long cytoplasmic processes of melanocytes extending between the keratinocytes of what layer?

spinous layer

27

Melanin is produced by oxidation of ... within...

tyrosine within melanosomes

28

Lack of pigmentation, albinism, is due to lack of ...

tyrosinases

29

What breaks down melanin in keratinocytes?

lysosomal activity

30

Lysosomal breakdown of melanin in keratinocytes occurs most rapidly in ...

light-skinned races

31

Dendritic cells in the supra basal layers of the epidermis?

Cells of Langerhans

32

The cytoplasm of Cells of Langerhans is distinguished by rod or flask-shaped ....

Birbeck granules

33

Cells of Langerhans are regarded as an .... cell, probably of bone-marrow origin.

antigen-presenting cell

34

Cells of Langerhans migrate into dermis to... by interacting with lymphocytes in lymphatics

initiate immune response

35

Modified keratinocytes, granule-containing cells

Merkel cells

36

Merkel cells are regularly associated with ...

nerve terminals

37

Merkel cells have what function?

mechanoreceptive

38

The dermis is a layer of ... subjacent to the epidermis

connective tissue

39

At the interface of the epidermis and dermis is the basement membrane which is the location of collagen types..., that help establish the strength of the dermal-epidermal junction.

Types III, IV, VII

40

The papillary layer of the dermis is a layer of loosely textured connective tissue containing what types of collagen? along with elastic fibers.

Type I and Type III collagen

41

What are the elastic fibers of the papillary dermal layer labeled as?

elaunin and oxytalan fibers

42

The elastic fibers (elaunin and oxytalan) of the papillary dermal layer are rich in the protein ...; also significant component of the periodontal ligament

fibrillin

43

The papillary layer sends finger-like projections, the ..., into the overlying epidermis.

dermal papillae

44

The epidermis that lies between the dermal papillae is referred to as...

epidermal pegs or rete ridges

45

In thick skin parallel arrays of dermal papillae cause ridges to be formed at the free surface of the skin; separated by grooves & run parallel to one another. They are the basis for fingerprints.

dermal ridges

46

What in the papillary layer of the dermis provides oxygen and nutrient supply for the overlying epidermis?

capillary loops

47

Sensor nerve endings located in the dermal papillae, that innervate..., which are sensory for touch and pressure

Meissener's corpuscles

48

The reticular layer of the dermis is the classic example of ...

dense, irregularly arranged CT

49

Which of the layers compromises the bulk of the dermis?

reticular layer

50

The reticular layer of the dermis consists mainly of what, giving skin both its toughness and resiliency?

Type I collagen with a liberal sprinkling of elastic fibers

51

What 3 things is the ground substance of the reticular layer of the dermis composed of?

hyaluronic acid, chondroitin sulfate and dreamt sulfate

52

Which layer of the dermis contains the appendages of skin, glands and/or hair follicles?

reticular layer

53

The reticular layer of the dermis experiences a loss of what, with aging?

hyaluronic acid and associated water

54

Hypodermis serves in certain locations as a major site for...

fat storage

55

What transverse the hypodermic, connecting the dermis with the deep fascia?

collagenous septae & the retinacula cutis

56

In what layer are the Pacinian corpuscles?

Hypodermis

57

Pacinian corpuscles are structures with multiple layers of flattened cells enclosing sensor nerve endings; the corpuscles are mechanoreceptors sensitive to ...

vibration and deep pressure

58

What are the 2 types of sweat glands?

eccrine & apocrine

59

Simple, tubular glands occurring over most of the body, independent of hairs.

Eccrine (merocrine) glands

60

The secretory segments of eccrine glands are coiled and lined with ..., which are described as "clear" or "dark" when examined by EM.

cuboidal/columnar cells

61

What product do the dark cells of the eccrine glands secrete?

release a proteinaceous product

62

Duct segments of sweat glands are lined with?

stratified cuboidal epithelium

63

Gland innervation of eccrine glands is?

cholinergic

64

Larger simple tubular glands, distribution limited to axillary, circumanal regions, external genitalia, and areola and nipple of the mammary gland. Connect with hair follicles and become functional at puberty.

Apocrine glands

65

The secretory segment of apocrine glands is lined with..., whose proteinaceous secretion is stored in a dilated-appearing lumen.

simple cuboidal epithelium

66

Apocrine secretion contains ...

pheromones

67

Apocrine gland innervation is ...

adrenergic

68

Generally associated with hair follicles; closely associated with smooth muscle fibers may assist in rupture of secretory cells.

Sebaceous glands

69

sebaceous glands have a simple acing form, with a short duct that empties into a neighboring ...

hair follicle

70

Sebaceous glands cells arise by ... in the basal layer of the acinus.

mitosis

71

As the cells of the sebaceous gland reach the duct, the lipid-packed cells degenerate creating ...

sebum

72

Sebaceous glands use what kind of secretion mechanism?

holocrine

73

Hair follicles arise as ingrowths of the ...

surface epithelium

74

Continuous series of air pockets at the center of the hair

medulla

75

dense, compacted "hard" keratin; the cells that give rise to the ... undergo a process of keratinization

cortex

76

layer of keratinized scale-like cells covering the hair

cuticle

77

What attach to the hair follicles and are capable of erecting and extending them; basis of "goose bumps"?

arrector pili muscles, & delicate bundles of smooth muscle fibers

78

The region where new nail is formed; can be seen through the nail at is base as the "moon"; is called the?

matrix

79

If the ... is destroyed, a nail will not regrow.

matrix

80

What 2 skin appendages are not present in thick skin?

hair and sebaceous glands