Week 2 - Integumentary System - Marisa Flashcards Preview

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Flashcards in Week 2 - Integumentary System - Marisa Deck (87)
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2
Q

organs of the integumentary system include

A

skin and its accessory structures: hair, nails, glands, blood vessels, muscles & nerves

3
Q

dermatology

A

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

4
Q

what is the largest organ of the body

A

cutaneous membrane (skin)

5
Q

what is the difference between the epidermis and dermis

A

EPIDERMIS: outer, thinner, 5 layers. Composed of epithelial cells, is the outermost protective shield of the body. Non-vascularized; therefore nutrients reach the epidermis by diffusing through the tissue fluid from blood vessels in the dermis. DERMIS: inner, thicker, 2 layers. Makes up the bulk of the skin, is a tough, leathery layer composed mostly of fibrous connective tissue. Vascularized.

6
Q

what is the layer beneath the dermis called & what is its function

A

Hyopdermis or subcutaneous layer. It anchors skin to the underlying tissues and organs, stores fat, acts as a shock absorber, and acts as an insulator to reduce heat loss. It also contains lamellated corpuscles which detect external pressure applied to the skin.

7
Q

what is the epithelium epidermis composed of

A

keratinized stratified squamous epithelium. Consists of 4 distinct cell types and 4-5 distinct layers

8
Q

what are the four types of cells in the epidermis?

A
  1. keratinocytes 2. langerhans cells (dendritic) 3. melanocytes 4. merkel cells (tactile)
9
Q

what do keratinocytes produce and what is their function

A
  1. keratin; the fibrous protein that helps give the epidermis its protective proterties. 2. lamellar granules; release water and acts as a repellant or sealant
10
Q

keratinocytes

A

tightly connected to one another by desmosomes, arise in the deepest part of the epidermis. These cells undergo constant mitosis and are pushed upwards by the production of new cells below them, causing millions of keratinocytes to rub off every day giving us a totally new epidermis every 25 to 45 days.

11
Q

what do melanocytes produce and what is their function

A

melanin; protects against UV radiation

12
Q

90% of epidermis cells are

A

keratinocytes

13
Q

what is another name for langerhans cells and why

A

dendritic cells or intraedpidermal macrophage cells.They arise from bone marrow and migrate to the epidermis where they ingest foreign substances and are key activators of our immune system

14
Q

what is another name for merkel cells and what is their function

A

tactile epithelial cells; every tactile cell is intimately associated with a disclike sensory nerve ending and therefore functions as a sensory receptor for touch

15
Q

how many layers compose the epidermis

A

5; 4 thin skin layers and 1 thick skin layer

16
Q

the layer of thick skin of the epidermis is called

A

stratum lucidum; ie: tinger tips, palms, soles of feet

17
Q

what is the layer of the epidermis that is composed mostly of keratinocytes

A

stratum spinosum

18
Q

what is the layer of the epidermis that includes keratohyalin and lamellar granules

A

stratum granulosum

19
Q

what is the epidermis layer where cell division occurs & therefore produces all other layers

A

stratum basale aka stratum germinativum

20
Q

what is the most superficial layer of the epidermis

A

stratum corneum

21
Q

what is the deepest epidermis layer

A

stratum basale aka stratum germinatiuvum

22
Q

what is the stratum corneum composed of

A

many flat sublayers of dead keratinocytes called corneocytes or squames

23
Q

corneum means

A

dead skin cells

24
Q

how is a callus formed

A

through constant friction of the stratum corneum

25
Q

list the order of the epidermis layers from superficial to deep

A

stratum corneum, startum lucidum (only on thick skin), stratum granulosum, stratum spinosum, stratum basale

26
Q

keratinization

A

the accumulation of more and more protective keratin, occurs as cells move from the deepest layer to the surface

27
Q

what is the skin structure that thickens heavily when one gains weight?

A

hypodermis

28
Q

what is the layer of the epidermis that appears to be absent in thin skin

A

stratum lucidum

29
Q

in what layer of the epidermis do keratinocytes appear to have prickly spines

A

stratum spinosum

30
Q

what is the function of keratohyalin and lamellar granules

A

keratohyalin helps form keratin in the upper layers, lamellar granules contain a water-resistent glycolipid that is spewed into the extracellular space and is a major factor in slowing water loss across the epidermis

31
Q

what is the dermis composed of

A

connective tissue containing collagen and elastic fibers2 layers: papillary layer and reticular layer

32
Q

which layer of the dermis is thin and superficial

A

papillary layer

33
Q

dermal papillae

A

contain capillary loops & house free nerve endings (pain receptors) and touch receptors called tactile or meissner’s corpuscles

34
Q

which layer of the dermis consists of dense connective tissue containing thin collagen and elastic fibers, dermal papillae, corpuscles of touch, and free nerve endings?

A

papillary layer

35
Q

which layer of the dermis consists of dense irregular connective tissue containing collagen and elastic fibers which provide strength, extensibility, and elasticity to the skin, adipose cells, hair follicles, nerves, sebaceous glands, and sweat glands?

A

reticular layer

36
Q

what layer of the dermis accounds for about 80% of the thickness of it

A

reticular layer

37
Q

what are tension lines

A

aka cleavage lines; indicate the predominant direction of underlying collagen fibers

38
Q

what layer of the dermis can tension lines be found in

A

reticular layer

39
Q

epidermal ridges

A

refelct contours of the underlying dermal papillae and form the basis for fingerprints/footprints. Their function is to increase firmness of grip by increasing friction

40
Q

what are the three pigments that contribute to skin color

A

melanin, carotene, and hemoglobin

41
Q

what happens when we expose our skin to sunlight

A

keratinocytes secrete chemicals that stimulate melanocytes causing melanin to build up in order to protect our skin cells from UV radiation by absorbing rays and dissipating the energy as heat.

42
Q

what color is melanin pigment

A

reddish yellow to brownish black

43
Q

what color pigment is carotene

A

yellow to orange

44
Q

where is melanin mostly located

A

in the epidermis

45
Q

where is carotene mostly located

A

in the stratum corneum, dermis, and subcutaneous layer

46
Q

albinism

A

an inherited inability to produce melanin

47
Q

vitiligo

A

a condition in which there is a partial or complete loss of melanocytes

48
Q

where is hemoglobin mostly located

A

in erythrocytes flowing through dermal capillaries

49
Q

what are the primary functions of hair (pili)

A

protection, reduction of heat loss, and sensing light touch

50
Q

what is hair composed of

A

dead, keratinized epidermal cells

51
Q

each hair consists of:

A
  1. shaft, which mostly projects above the surface of the skin. 2. root, which penetrates into the dermis. 3. hair follicle, which surrounds the root and consists of an epithelial root sheath which in turn is surrounded by a dermal root sheath
52
Q

what is located at the base of a hair follicle

A

the bulb

53
Q

what is the indentation on the hair follicle where blood vessels provide nourishment to the growing hair

A

papilla of the hair

54
Q

where does cell division of the hair occur

A

in the hair matrix of the bulb

55
Q

what is the growth cycle of hair

A

growth stage, regression stage, resting stage

56
Q

hair root plexus

A

a knot of sensory nerve endings which wraps around each hair bulb

57
Q

the color of one’s hair is determined by what

A

the amount and type of melanin

58
Q

what are the different types of hairs

A

lanugo, vellus hairs (the pale, fine body hair of children and adult females) , terminal hairs (coarser, longer hair of the eyebrows and scalp)

59
Q

what are nails composed of

A

hard, keratinized epidermal cells located over the dorsal surfaces of the ends of fingers and toes

60
Q

each nail consists of:

A
  1. a free edge 2. a transparent nail body (plate) with a whitish lunula at its proximal end 3. a nail root embedded in a fold of skin
61
Q

hyponychium

A

nail bed (located under free edge of nail) attaches nail to the fingertip

62
Q

eponychium

A

(cuticle) attaches the margin of nail wall to neighboring epidermis

63
Q

nail matrix

A

the thickened proximal portion of the nail bed, responsible for nail growth

64
Q

where are sebaceous glands found

A

typically connected to hair follicles all over the body except in the thick skin of the palms and soles

65
Q

what is the function of sebaceous glands

A

to secrete an oily substance - sebum, which prevents dehydration of hair and skin, and inhibits growth of certain bacteria

66
Q

where and what are sudoriferous glands

A

sweat glands (produce perspiration), which are distributed over the entire skin surface except the nipples and parts of the external genitalia.

67
Q

what are the two types of sudiferous glands

A

eccrine & apocrine

68
Q

eccrine sweat glands

A

(merocrine glands) which have an excretory duct that opens at a pore at the surface of the epidermis; the sweat is secreted by these glands. they help to cool the body by evaporating, eliminate small amounts of waste, responsible for emotional sweating or cold sweat.

69
Q

apocrine sweat glands

A

located mainly on the skin of the axilla, groin, areolae, and bearded facial regions of adult males; their excretory ducts open into hair follicles

70
Q

when is apocrine sweat secreted

A

during emotional stress and sexual excitement

71
Q

myoepitheliocytes

A

help squeeze out secretions into their hair follicles

72
Q

ceruminous glands

A

modified sweat glands located in the ear canal; 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 the ear canal.

73
Q

where is thin (hairy) skin found on the body

A

on all body regions except the palms, palmar surfaces of digits, and soles

74
Q

where is thick (hairless) skin found on the body

A

covers the palms, palmar surfaces of digits, and soles

75
Q

what are the functions of the skin

A
  1. thermoregulation 2. blood reservoir 3. protection 4. cutaneous sensations 5. excretion and absorbtion 6. synthesis of vitamin D
76
Q

where does the dermis receive its blood from

A
  1. branches of arteries supplying skeletal muscles 2. arteries that supply the skin directly, including: cutaneous plexus and papillary plexus
77
Q

venous plexus

A

drains blood from the dermis into larger subcutaneous veins

78
Q

development of the integumentary system

A

the epidermis develops from the ectoderm; nails, hair, skin = epidermal derivatives. The epidermis of a fetus is protected by a fatty substance called vernix caseosa. The dermis developes from the mesoderm

79
Q

what are some effects of aging people begin to see in their late forties

A

wrinkling, decrease of skin’s immune responsiveness, dehydration and cracking of skin, decreased sweat production, decreased numbers of functional melanocytes resulting in gray hair and atopical skin pigmentation, loss of subcutaneous fat, general decrease in skin thickness, and an increased susceptibility to pathological conditions

80
Q

what are some effects of aging that occur during the second and third decades of life

A

decrease in growth of hair and nails, brittle nails

81
Q

which epidermal cell type is most numerous

A

keratinocyte

82
Q

which cell functions as part of the immune system

A

dendritic cells

83
Q

the epidermis provides a physical barrier due largely to the presence of:

A

keratin

84
Q

skin color is determined by

A

the amount of blood, pigments, and oxygenated level of the blood

85
Q

the sensations of touch and pressure are picked up by receptors located in

A

the dermis

86
Q

skin surface markings that reflect points of tight dermal attachment to underlying tissues are called

A

flexure lines

87
Q

an arrector pili muscle can_

A

cause a hair to stand up straight

88
Q

the product of this type of sweat gland includes protein and lipid substances that become odoriferous as a result of bacterial action

A

apocrine gland