Chapter 5 Flashcards

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1
Q

Integumentary System

A

composed of the skin, hair, oil and sweat glands, nails, and sensory receptors.

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2
Q

Dermatology

A

the medical specialty that deals with the structure, function,
and disorders of the integumentary system.

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3
Q

Another word for skin

A

cutaneous membrane

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4
Q

Skin

A

covers the external surface of the body and is the largest organ of the body in weight.

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5
Q

Epidermis

A

The superficial, thinner portion of skin, which is composed of
epithelial tissue

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6
Q

Dermis

A

deeper, thicker connective tissue portion

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7
Q

Subcutaneous Layer

A

Deep to the dermis, but not part of the skin. this layer consists of areolar and adipose tissues.

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8
Q

Another word for Subcutaneous Layer

A

hypodermis

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9
Q

lamellated
corpuscles

A

(pacinian corpuscles)
Nerve endings in the subcutaenous layer. Sensitive to pressure.

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10
Q

What is the epidermis composed of (4 cells)

A

keratinized stratified squamous
epithelium. It contains four principal types of cells: keratinocytes,
melanocytes, intraepidermal macrophages, and tactile epithelial cells

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11
Q

keratinocytes

A

90% of epidermal cells. which are arranged
in four or five layers and produce the protein keratin

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12
Q

Keratin

A

a tough, fibrous protein that helps protect the skin and underlying tissues from abrasions,
heat, microbes, and chemicals.

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13
Q

lamellar
granules

A

Produced by keratinocytes. Release a water-repellent sealant that decreases water entry and loss and inhibits the entry of foreign materials.

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14
Q

Melanocytes

A

8% of epidermal cells. develop from the ectoderm of a developing embryo and produce the pigment melanin. Their
long, slender projections extend between the keratinocytes and
transfer melanin granules to them.

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15
Q

Melanin

A

a yellowred or brown-black pigment that contributes to skin color and absorbs damaging ultraviolet (UV) light.

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16
Q

Intraepidermal macrophages

A

arise from red bone marrow and migrate to the epidermis where they constitute a small fraction of the epidermal cells. They participate in immune responses mounted against microbes that invade the skin, and are easily damaged by UV light. Their role in the immune response is to help other cells of the immune system recognize an invading microbe and destroy it.

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17
Q

Tactile epithelial cells

A

the least
numerous of the epidermal cells. They are located in the deepest layer
of the epidermis, where they contact the flattened process of a sensory neuron, a structure called a tactile disc

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18
Q

Tactile Disc

A

Sensory neuron that detects touch sensations.

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19
Q

the epidermis has four strata or layers—stratum basale, stratum spinosum, stratum granulosum, and a thin stratum corneum. This is called:

A

Thin Skin

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20
Q

Where exposure to friction is greatest, such as in the
fingertips, palms, and soles, the epidermis has five layers—stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and
a thick stratum corneum. This is called:

A

Thick Skin

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21
Q

Stratum Basale

A

Deepest layer of epidermis. composed of a single row of cuboidal or columnar keratinocytes. Some cells in this layer
are stem cells.

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22
Q

stem cells

A

undergo cell division in Stratum Basale to continually produce new keratinocytes.

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23
Q

Stratum Spinosum

A

consists of numerous keratinocytes arranged in 8–10 layers. Superficial to Stratum Basale

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24
Q

Stratum Granulosum

A

consists of three to five layers of flattened keratinocytes that are undergoing apoptosis.

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25
Q

keratohyalin

A

A distinctive feature of cells in Stratum Granulosum is the presenceof darkly staining granules of this protein.

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26
Q

Lamellar Granules

A

present in the keratinocytes. fuse with the plasma membrane and release a lipid-rich secretion.

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27
Q

Stratum Lucidum

A

present only in the thick skin of areas such as the fingertips, palms, and soles. It consists of four to six layers of flattened clear, dead keratinocytes that contain large amounts of keratin and
thickened plasma membranes.

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28
Q

Statum Corneum

A

25 to 30 layers of flattened dead
keratinocytes. extremely thin, flat,
plasma membrane–enclosed packages of keratin that no longer
contain a nucleus or any internal organelles.

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29
Q

final product
of the differentiation process of the keratinocytes

A

Stratum Corneum

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30
Q

Callus

A

an abnormal
thickening of the stratum corneum

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31
Q

Keratinization

A

Newly formed cells in the stratum basale are slowly pushed to the
surface. As the cells move from one epidermal layer to the next, they accumulate more and more keratin.

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32
Q

Epidermal Growth Factor

A

Hormone like proteins that play a role in keratinzation

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33
Q

Dermis

A

The second, deeper part of the skin. composed of dense
irregular connective tissue containing collagen and elastic fibers.

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34
Q

Papillary Region

A

makes up about one-fifth of the thickness
of the total layer of the dermis. contains thin collagen and fine
elastic fibers.

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35
Q

dermal papillae

A

small, nipple-shaped structures that project into the undersurface of the epidermis

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36
Q

Capillary Loops

A

Blood vessels that dermal papillae contain.

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37
Q

Corpuscles of touch

A

Nerve endings sensitive to touch that the dermal papillae sometimes contains.

38
Q

Free Nerve Endings

A

dendrites that lack any apparent structural specialization. Diff erent free nerve endings initiate signals that give rise
to sensations of warmth, coolness, pain, tickling, and itching. Dermal Papillae sometimes contain.

39
Q

Reticular Region

A

contains bundles of thick collagen fibers, scattered fibroblasts, and various wandering cells. Attached to subcutaneous layer.

40
Q

extensibility

A

ability to stretch

41
Q

elasticity

A

the ability to return to original shape after stretching.

42
Q

epidermal ridges

A

produced during the third month of fetal development as
downward projections of the epidermis into the dermis between the
dermal papillae of the papillary region. create a strong bond between the epidermis and dermis in a region of high mechanical stress.

43
Q

Because the ducts of
sweat glands open on the tops of the epidermal ridges as sweat pores,
the sweat and ridges form:

A

fingerprints (or footprints)

44
Q

three pigments that impart awide variety of colors to skin:

A

Melanin, hemoglobin, and carotene

45
Q

Hair

A

present on most skin surfaces except the
palms, palmar surfaces of the fingers, the soles, and plantar surfaces
of the feet.

46
Q

Anatomy of a Hair

A

hair shaft, hair root, hair follicle, hair bulb, hair matrix

47
Q

Hair Shaft

A

the superficial portion of the hair, which projects above the surface of the skin.

48
Q

Hair Root

A

the portion of the
hair deep to the shaft that penetrates into the dermis, and sometimes
into the subcutaneous layer.

49
Q

The shaft and root of the hair both consist
of three concentric layers of cells:

A

medulla, cortex, and cuticle of the hair

50
Q

Hair Follicle

A

made up of an external root sheath and an internal root sheath

51
Q

external root sheath

A

downward continuation of the epidermis

52
Q

internal root sheath

A

produced by
the matrix (described shortly) and forms a cellular tubular sheath of epithelium between the external root sheath and the hair.

53
Q

Together,
the external and internal root sheath are referred to as the:

A

epithelial root sheath

54
Q

The dense dermis surrounding the hair follicle is called
the:

A

dermal root sheath

55
Q

Hair Bulb

A

The base of each hair follicle and its surrounding dermal root sheath is an onion-shaped structure

56
Q

The hair bulb houses a nipple-shaped indentation which contains areolar connective tissue and many blood vessels that nourish
the growing hair follicle:

A

papilla of the hair

57
Q

hair matrix

A

Located in the bulb. responsible for the growth of existing hairs, and they produce new hairs when old hairs are shed.

58
Q

arrector pili

A

Sebaceous (oil) glands (discussed shortly) and a bundle of smooth
muscle cells are also associated with hairs. The smooth muscle is arrector pili

59
Q

hair root plexus

A

Surrounding each hair follicle are dendrites of neurons that form the hair root plexus. sensitive to touch.

60
Q

Several kinds of exocrine glands are associated with the
skin:

A

sebaceous (oil) glands, sudoriferous (sweat) glands, and ceruminous glands.

61
Q

Sebaceous Glands

A

Oil Glands. simple, branched acinar (rounded) glands.

62
Q

Sebaceous glands secrete an oily substance called

A

Sebum

63
Q

Sudoriferous Glands

A

Sweat Glands. The cells of these glands
release sweat, or perspiration, into hair follicles or onto the skin
surface through pores.

64
Q

Sweat glands are divided into two main types:

A

eccrine and apocrine

65
Q

Eccrine Sweat Glands Function

A

to help regulate
body temperature through evaporation. Very common

66
Q

Thermoregulation

A

The homeostatic
regulation of body temperature

67
Q

thermoregulatory sweating

A

sweat first forms on the forehead and scalp
and then extends to the rest of the body, forming last on the palms and soles.

68
Q

insensible perspiration

A

Sweat that evaporates from the skin before it is perceived as moisture

69
Q

sensible perspiration

A

Sweat that is excreted in larger amounts and is seen as moisture on the skin

70
Q

Apocrine sweat glands

A

simple, coiled tubular glands but have larger ducts and lumens
than eccrine glands. their secretion is via exocytosis. contains the same components as eccrine sweat plus lipids and proteins. Odourless until in contain with bacteria on skin. Don’t function until puberty.

71
Q

Ceruminuous Glands

A

produce
a waxy lubricating secretion.

72
Q

cerumen

A

Ear Wax

73
Q

Nails

A

plates of tightly packed, hard, dead, keratinized epidermal
cells that form a clear, solid covering over the dorsal surfaces of the distal portions of the digits.

74
Q

Each Nail consists of:

A

nail body, a free
edge, and a nail root

75
Q

Nail Body

A

the visible portion of the nail. Most of the nail body appears pink because of blood flowing through the capillaries in the underlying dermis

76
Q

Free Edge

A

part of the nail body that may extend past the distal end of the digit. The free edge is white because there are no underlying capillaries.

77
Q

Nail Root

A

the portion of the nail that is buried in a fold of skin. The whitish, crescent-shaped area of the proximal end of the nail body is called
the lunula.

78
Q

Lunula

A

appears whitish because the vascular tissue underneath does not show through due to a thickened region of epithelium in the area

79
Q

Beneath the free edge is a thickened
region of stratum corneum called the:

A

hyponychium

80
Q

Nail Bed

A

the skin below the nail plate that extends from the lunula to the hyponychium. The epidermis of the nail bed lacks a stratum granulosum.

81
Q

eponychium

A

(Cuticle) narrow band of epidermis that extends from and adheres
to the margin (lateral border) of the nail wall.

82
Q

hangnail

A

a small torn piece of skin at the side or base of a fingernail or toenail, usually caused by dryness of the eponychium.

83
Q

The portion of the epithelium proximal to the nail root is the:

A

Nail Matrix

84
Q

Nails have a variety of functions:

A
  1. They protect the distal end of the digits.
  2. They provide support and counterpressure to the palmar surface of
    the fingers to enhance touch perception and manipulation.
  3. They allow us to grasp and manipulate small objects, and they can be used to scratch and groom the body in various ways.
85
Q

Two major types of Skin

A

thin (hairy) skin and thick (hairless) skin

86
Q

The skin contributes to thermoregulation in two ways:

A

by liberating sweat at its surface and by adjusting the flow of blood in the dermis.

87
Q

The dermis houses an extensive network of blood vessels that carry 8–10% of the total blood flow in a resting adult. For this reason, the skin acts as a:

A

Blood Resevoir

88
Q

Protection

A

Provided by skin.

89
Q

Cutaneous sensations

A

sensations that arise in the skin, including
tactile sensations touch, pressure, vibration, and tickling—as well as thermal sensations such as warmth and coolness.

90
Q

Synthesis of vitamin D

A

requires activation of a precursor molecule in
the skin by ultraviolet (UV) rays in sunlight.

91
Q
A