Week 2 - Integumentary System - Marisa Flashcards Preview

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

organs of the integumentary system include

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

3

dermatology

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

4

what is the largest organ of the body

cutaneous membrane (skin)

5

what is the difference between the epidermis and dermis

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

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

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

what is the epithelium epidermis composed of

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

8

what are the four types of cells in the epidermis?

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

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what do keratinocytes produce and what is their function

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

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keratinocytes

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.

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what do melanocytes produce and what is their function

melanin; protects against UV radiation

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90% of epidermis cells are

keratinocytes

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what is another name for langerhans cells and why

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

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

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

how many layers compose the epidermis

5; 4 thin skin layers and 1 thick skin layer

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the layer of thick skin of the epidermis is called

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

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

stratum spinosum

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

stratum granulosum

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

stratum basale aka stratum germinativum

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what is the most superficial layer of the epidermis

stratum corneum

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what is the deepest epidermis layer

stratum basale aka stratum germinatiuvum

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what is the stratum corneum composed of

many flat sublayers of dead keratinocytes called corneocytes or squames

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corneum means

dead skin cells

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how is a callus formed

through constant friction of the stratum corneum

25

list the order of the epidermis layers from superficial to deep

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

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keratinization

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

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

hypodermis

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

stratum lucidum

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

stratum spinosum

30

what is the function of keratohyalin and lamellar granules

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

what is the dermis composed of

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

32

which layer of the dermis is thin and superficial

papillary layer

33

dermal papillae

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

34

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?

papillary layer

35

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?

reticular layer

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

reticular layer

37

what are tension lines

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

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what layer of the dermis can tension lines be found in

reticular layer

39

epidermal ridges

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

what are the three pigments that contribute to skin color

melanin, carotene, and hemoglobin

41

what happens when we expose our skin to sunlight

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.

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what color is melanin pigment

reddish yellow to brownish black

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what color pigment is carotene

yellow to orange

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where is melanin mostly located

in the epidermis

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where is carotene mostly located

in the stratum corneum, dermis, and subcutaneous layer

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albinism

an inherited inability to produce melanin

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vitiligo

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

48

where is hemoglobin mostly located

in erythrocytes flowing through dermal capillaries

49

what are the primary functions of hair (pili)

protection, reduction of heat loss, and sensing light touch

50

what is hair composed of

dead, keratinized epidermal cells

51

each hair consists of:

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

what is located at the base of a hair follicle

the bulb

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

papilla of the hair

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where does cell division of the hair occur

in the hair matrix of the bulb

55

what is the growth cycle of hair

growth stage, regression stage, resting stage

56

hair root plexus

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

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the color of one's hair is determined by what

the amount and type of melanin

58

what are the different types of hairs

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

59

what are nails composed of

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

60

each nail consists of:

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

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hyponychium

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

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eponychium

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

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nail matrix

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

64

where are sebaceous glands found

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

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what is the function of sebaceous glands

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

66

where and what are sudoriferous glands

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

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what are the two types of sudiferous glands

eccrine & apocrine

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eccrine sweat glands

(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.

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apocrine sweat glands

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

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when is apocrine sweat secreted

during emotional stress and sexual excitement

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myoepitheliocytes

help squeeze out secretions into their hair follicles

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ceruminous glands

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

where is thin (hairy) skin found on the body

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

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where is thick (hairless) skin found on the body

covers the palms, palmar surfaces of digits, and soles

75

what are the functions of the skin

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

76

where does the dermis receive its blood from

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

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venous plexus

drains blood from the dermis into larger subcutaneous veins

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development of the integumentary system

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

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

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

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

decrease in growth of hair and nails, brittle nails

81

which epidermal cell type is most numerous

keratinocyte

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which cell functions as part of the immune system

dendritic cells

83

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

keratin

84

skin color is determined by

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

85

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

the dermis

86

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

flexure lines

87

an arrector pili muscle can_

cause a hair to stand up straight

88

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

apocrine gland