Integumentary System

Front 1

What are the 6 Funcitons of the skin and subcutaneous layer?

Back 1

1. Protection of underlying tissues, abrasion, and chemical attack
2. Excretion of salts, water, and organic wastes by integumentary glands
3. Maintenance of normal body temperature through either insulation or evaporative cooling
4.Synthesis of vitamin A steroid
5. Storage of nutrients
6. Detection of touch, pressure, pain, and temperature

Front 2

Why is it important for the skin to synthesize vitamin A?

Back 2

Because it is subsequently converted to the hormone calcitiol, important to normal calcium metabolism

Front 3

What is stored in the adipocytes in the dermis and in adipose tissue in the subcutaneous layer?

Back 3

Lipids

Front 4

What is the difference between thin skin and thick skin?

Back 4

Thin skin covers most of the exposed body surface
Thick skin covers the surfaces of the pams and soles

Front 5

Keratinocytes

Back 5

the body's most abundant epithelial cells that form several layers

Front 6

How many layers can be distinguished in thick skin?

Back 6

five

Front 7

How many layers can be distinguised in thin skin?

Back 7

four

Front 8

What do the terms "thick" and "thin" refer to?

Back 8

The relative thickness of the epidermis, not to the integument as a whole

Front 9

What reveals the pattern of epidermal ridges?

Back 9

Fingerprints

Front 10

What are the pits in fingerprints?

Back 10

The pits are the openings of the ducts of merocrine sweat glands

Front 11

What are the layers of skin from the basal lamina toward the free surface?

Back 11

1. Stratum Germinativum
2. Stratum Spinosum
3. Stratum Granuolosum
4. Stratum Lucidum
5. Stratum Corneum

Front 12

Stratum Germinativum

Back 12

the innermost epidermal layer, forms epidermal ridges, which extend into the dermis, i ncreasing the area of contact between the two regions

Front 13

Dermal Papillae

Back 13

Dermal projections that extend between adjacent epidermal ridges; increase the strength of the bond between epidermis and dermis

Front 14

What is the strength of the attachment between epidermis and dermis proportional to?

Back 14

The strength of the attachment is proportional to the surface area of the basal lamina

Front 15

What kind of cells dominate the stratum germinativum?

Back 15

Basal cells, which are stem cells whose divisions replace the more superficial keratinocytes that are lost or shed at the epithelial surface

Front 16

What kind of cells are contained in skin surfaces without hair?

Back 16

Specialized epithelial cells known as Merkel Cells

Front 17

What happens when Merkel cells are compressed?

Back 17

since they are sensitive to touch, they release chemicals that stimulate sensory nerve endings

Front 18

What do the brown tones of skin result from?

Back 18

the synthetic activities of pigment cells called melanocytes

Front 19

Stratum Spinosum

Back 19

2nd Deepest layer of skin, consists of 8-10 layers of cells, with the keratinocytes bound together by desmosomes

Front 20

Each time a stem cell divides, one of the daughter cells is pushed to the ______ _________ into the ________ ____________

Back 20

Stratum germinativum, stratum desmosomes

Front 21

Langerhans cells

Back 21

located in the stratum spinosum and responsible for stimulating defense against:
1. microorganisms that manage to penetrate the superficial layers of the epidermis
2. superficial skin cancers

Front 22

Stratum Granulosum

Back 22

the region superficial to the stratum spinosum, consists of 3-5 layers of keratinocytes displaced from the stratum spinosum

Front 23

Cells stop dividing and start making large amounts of the proteins keratin and keratohyalin by the time they reach what layer of epiderms?

Back 23

The Stratum granulosum

Front 24

Keratin

Back 24

a tough, fibrous protein that is the basic structural component of hair and nails

Front 25

What happens as keratin fibers develop?

Back 25

the cells grow thinner and flatter, their membrances thickening and becoming less permeable

Front 26

Keratohyalin

Back 26

forms dense granules in the cytoplasm that promote dehydration of the cell

Front 27

How does keratohyalin contribute to the death of a cell?

Back 27

Promotes aggregation and cross

Front 28

Stratum Lucidum

Back 28

in the thick skin of the palms and soles, a glassy stratum lucidum covers the stratum granulosum

Front 29

Describe the cells in the stratum lucidum

Back 29

the cells in the stratum lucidum are flattened, densely packed, and filled with keratin

Front 30

Stratum corneum

Back 30

at the exposed surface of both thick and thin skin, contains 15-30 layers of keratinized cells

Front 31

Describe how water affects the stratum corneum

Back 31

the stratum corneum is water resistant, but not waterproof. Water from the interstitial fluids slowly penetrates the surface, to be evaporated into the surrounding air

Front 32

Keratinization

Back 32

AKA cornification, formation of protective, superficial layers of cells filled with keratin

Front 33

How do the dead cells in each layer of stratum corneum stay intercononected?

Back 33

The dead cells in each layer of the stratum corneum remain tightly interconnected by desmosomes. The connections are so secure that keratinized cells are generally shed in large groups or sheets

Front 34

How long does it take for a cell to move from the stratum germinativum to the stratum corneum?

Back 34

15-30 days

Front 35

How long do the dead cells remain in the exposed stratum corneum layer before they are shed or washed away?

Back 35

About 2 weeks

Front 36

Insensible perspiration

Back 36

you lose 500 ml (about 1 pt) of water in this way each day.

Front 37

What causes insensible perspiration?

Back 37

damage to the epidermis, it breaks the connections between superficial and deeper layers of the epidermis, this is how blisters occur

Front 38

Name 3 types of extreme skin conditions

Back 38

1. xerosis (excessively dry skin)
2. hypertonic conditions
3. hypotonic conditions

Front 39

What is the color of your skin a result of?

Back 39

An interaction between epidermal pigmentation and dermal circulation

Front 40

The spidermis contains variable quantities of what 2 pigments?

Back 40

1. carotene
2. melanin

Front 41

Carotene

Back 41

an orange-yellow pigment that normally accumulates in epidermal cells

Front 42

Where is carotene most apparent in light-skinned inviduals?

Back 42

in the cells of the stratum corneum

Front 43

Carotene can be converted to vitamin A, which is required for what?

Back 43

1. normal maintenenance of epithelia
2. synthesis of photoreceptor pigments in the eye

Front 44

Melanin

Back 44

a brown, yellow-brown, or black pigment produced by melanocytes

Front 45

Where are melanocytes located?

Back 45

in the stratum germinativum squeezed between or deep to the epithelial cells

Front 46

What do melanocytes do?

Back 46

manufacture the pigment melanin from molecules of the amino acid tyrosine

Front 47

How does UV Radiation affect the skin?

Back 47

UV radiation can damage DNA, cause mutations, and promotes cancer

Front 48

How does skin cancer develop from UV Radiation?

Back 48

develop from chromosomal damage in germanitive cells or melanocytes

Front 49

Basal Cell Carcinoma

Back 49

malignant cancer that originates in the stratum germinativum, most common skin cancer, rarely metasticizes

Front 50

Squamous Cell Carcinoma

Back 50

Less common, almost totally restricted to areas of sun-exposed skin, treatment invovles the surgical removal, rarely metasticizes

Front 51

Malignant melanomas

Back 51

extremely dangerous, cancerous melanocytes grow rapidly, can metastisize through lyphatic system

Front 52

What are frekles the result of?

Back 52

melanocytes that are producing larger-than-average amounts of melanin

Front 53

What are 4 diseases that impact pigments?

Back 53

1. Jaundice
2. Tumors affecting pituitary gland
3. Addison's disease
4. Vitilligo

Front 54

Dermis

Back 54

Lies between the epidermis and the subcutaneous layer. Has two major components.

Front 55

What are the two major components of the dermis?

Back 55

1. a superficial papillary layer
2. a deeper reticular layer

Front 56

What does the papillary layer of the dermis consist of?

Back 56

areolar tissue, contains the capillaries and sensory neurons that supply the surface of the skin

Front 57

What does the reticular layer of dermis consist of?

Back 57

deep to the papillary layer, consists of an interwoven meshwork of dense, irregular connective tissue.

Front 58

Describe the boundary between the papillary and reticular layers

Back 58

The boundary between the two layers is indistinct. Collagen extends to reticular layer to blend into superficial papillary layer

Front 59

What is contained in the reticular and papillary layers of the dermis?

Back 59

networks of blood vessels, lymph vessels, and nerve fibers

Front 60

Where are all the cells of the connective tissue proper contained?

Back 60

In the dermis

Front 61

Dermatitis

Back 61

an inflammation of the skin that primarily involves the papillary layer; causes itching, no pain or severe pain

Front 62

How does dermatitis typically begin?

Back 62

The inflammation typically begins in a part of the skin exposed to infection or irritated by chemicals, radiation, or mechanical stimuli.

Front 63

Skin tugor

Back 63

the flexibility and resilience of the skin; this is maintained by the water content of the skin

Front 64

What reduces the amount of elastin in the dermis?

Back 64

Destructive effects of aging, hormones, and UV radiation. This produces wrinkles and sagging skin

Front 65

Tretinoin

Back 65

Derivative of vitamin A that can be applied to the skin as a cream or gel. It increases the blood flow to the dermis and stimulates dermal repair

Front 66

Cutaneous Plexus

Back 66

Arteries supplying the skin form a network in the subcutaneous layer along its border with the reticular later of the dermis

Front 67

Tributaries of the cutaneous plexus supply which tissues?

Back 67

Tributaries of these arteries supply the adipose tissues of the subcutaneous layer and the tissues of the integument

Front 68

Papillary plexus

Back 68

a branching network of small arteries that provides arterial blood to capillary loops that follow the contours of the epidermis-dermis boundary

Front 69

Venous plexus

Back 69

A network of small veins where capillaries that follow the epidermis-dermis boundary empty into

Front 70

The connective tissue fibers of the reticular layer are extensively interwoven with those of the __________ _____________, or hypodermis.

Back 70

Subcantaneous Layer

Front 71

Why is an indistinct boundary between the reticular layer and the subcantaneous layer important?

Back 71

it is important in stabilizing the position of the skin in relation to underlying tissues while permitting independent movement

Front 72

What is the purpose of Subcantaneous Fat?

Back 72

Baby fat, helps reduce heat loss in children, serves as substantial energy reserve, shock absorber for the rough-and-tumble years

Front 73

Lanugo

Back 73

hairs that first appear after roughly three months of embryonic development, extremely fine and unpigmented, most are shed before birth

Front 74

What are two types of hair that replace lanugo in the adult integument?

Back 74

1. vellus hairs - "peach fuzz" hairs located over much of the body surface
2. terminal hairs - heavy, more deeply pigmented hairs

Front 75

Whem do vellus hairs turn into terminal hairs?

Back 75

Vellus hairs are present at the armpits, pubic area, and limbs until puberty. Thereafter, the follicles produce terminal hairs in response to circulating sex hormones

Front 76

Variations in hair color are a reflection of what?

Back 76

Variations in color reflect differences in structure and variations in the pigment produced by melanocytes at the hair papilla

Front 77

What is white / gray hair a result of?

Back 77

White hair results from the combination of a decrease in pigment production and the presence of air bubbles in the medulla of the hair shaft

Front 78

What is the function of hair?

Back 78

roughly 500,000 hairs on your head protect your scalp from UV light, help cushion a light blow to the head, and insulate the skull

Front 79

Why are their sensory nerves at the base of each hair follicle?

Back 79

to provide sensitivity as an early warning system that may help prevent injury

Front 80

Arrector Pili

Back 80

ribbons of smooth muscle that extend from the papillary layer of the dermis to the connective tissue sheath surrounding the hair follicle

Front 81

What happens when the arrector pili are stimulated?

Back 81

the arrector pili pulls on the follicles and forces the hairs to stand erect

Front 82

What is the first step in hair production?

Back 82

basal cells near the center of the hair matrix divide, producing daughter cells that are gradually pushed toward the surface

Front 83

What is the second step in hair production?

Back 83

those cells closest to the center of the matrix form the medulla, cells closer to the edge of the developing hair form the cortex, and those at the outer margins form the cuticle.

Front 84

In hair production, when is keratinization complete?

Back 84

by the time the cells approach the surface (the start of the hair shaft), keratinization is complete and the cells of the medulla, cortex, and cuticle are dead

Front 85

What are the 3 concentric layers of the epithelial cells of the folicle walls?

Back 85

1. Internal Root Sheath
2. External Root Sheath
3. Glassy Membrane

Front 86

Internal Root Sheath

Back 86

Surrounds the hair root and the deeper portion of the shaft, produced by the cells at the periphery of the hair matrix, this layer does not extend the entire length of the follicle

Front 87

External Root Sheath

Back 87

Longitudinal section extends from the skin surface to the hair matrix, where the external root sheath joins the hair matrix, all the cells resemble those of the stratum germinativum

Front 88

Glassy Membrane

Back 88

Thickened basal lamina wrapped in a dense connective tissue sheath. This membrane is in contact with the surrounding connective tissues of the dermis

Front 89

At what rate does hair grow?

Back 89

a hair in the scalp grows for 2-5 years, at a rate of about .33mm per day

Front 90

What are the 2 types of exocrine glands contained in the skin?

Back 90

1. Sebaceous glands
2. Sweat glands

Front 91

Sebaceous glands

Back 91

produce oily lipid that coats hair shafts and the epidermis

Front 92

Sweat glands

Back 92

produce a watery solution and perform other special functions

Front 93

Apocrine sweat glands

Back 93

located in the axillae, groin, and nipples produce a thick, odorous fluid and begin secreting at puberty

Front 94

Why does sweat have a strong odor?

Back 94

the sweat produced is a nutrient source for bateria

Front 95

Myoepithelial cells

Back 95

surround the secretory cells in apocrine sweat glands, contract and squeeze the gland and thereby discharge the accumulated secretion into the hair follicles

Front 96

Merocrine sweat glands

Back 96

produce a watery fluid, more numerous and widely distributed than apocrine glands

Front 97

What are 3 functions of merocrine sweat glands?

Back 97

1. cooling the surface of the skin to reduce body temperature
2. excreting water and electrolytes, or drugs
3. providing protection from environmental hazards

Front 98

How does sweat dilute harmful chemicals and discourage the growth of microorganisms?

Back 98

1. by flushing them from the surface or making it difficult for them to adhere to the epidermal surface
2. through the action of dermicidin, a small peptide that has powerful antibiotic properties

Front 99

Mammary glands

Back 99

a specialized gland of the breast, a complex interaction between sex hormones and pituitary hormones control their development and secretion

Front 100

Ceruminous glands

Back 100

modified sweat glands in the passageway of the external ear

Front 101

What is earwax?

Back 101

Secretions from the ceruminous glands combined with those of nearby subaceous glands - called cerumen