Chapter 5 Integumentary System

Question 0

Functions of integumentary system

Answer 0

Regulates body temperature
Stores blood
Protects from external environment
Detects cutaneous sensations
Excretes and absorbs substances
Synthesizes Vit D

Question 1

Components of integumentary system

Answer 1

Hair
Skin
Nails
Oil and sweat glands
Sensory receptors

Question 2

Subcutaneous layer

Answer 2

Deep to dermis (hypodermis)
Areolar and adipose tissue
Storage depot for fat

Question 3

Lamellated (pacinian) corpuscle

Answer 3

Nerve ending
Sensitive to pressure
In subcutaneous and sometimes dermis

Question 4

Epidermis cells and tissue type

Answer 4

Keratinized stratified squamous epithelium

Keratinocytes
Melanocytes
Intrepidermal macrophages
Tactile epithelial cells

Question 5

Keratinocyte fxns

Answer 5

Produce protein keratin
Produce lamellar granules which release water repellant sealant that decreases water entry and loss and inhibits the entry of foreign materials

Question 6

Melanocytes

Answer 6

Develop from ectoderm
Produce pigment melanin
Transfer melanin granules to keratinocytes
Susceptible to UV damage

Question 7

Melanin

Answer 7

Yellow red to brown black
Absorbs UV light
In keratinocytes they cluster to form protective layer on side toward skin surface
Shield nuclear damage

Question 8

Intraepidermal macrophages

Answer 8

From red bone marrow
(Langerhans cells)
Immune responses against microbes
Help cells recognize invading microbe and destroy it

Question 9

Tactile epithelial cells

Answer 9

Merkel cells
Least numerous of epidermal cells
Detect touch sensations
Deepest layer of epidermis

Question 10

4 strata layers of epidermis

Answer 10

Stratum basale
Stratum spinosum
Stratum granulosum
Stratum corneum

Question 11

Stratum basale

Answer 11

Deepest layer of epidermis
Cuboidal or columnar keratinocytes
(Stratum germanitivum)
Some cells are stem cells

Question 12

Skin graft

Answer 12

Transfer patch of healthy skin to cover a wound

New skin cannot regenerate if injury destroys large area of stratum basale

Question 13

Stratum spinosum

Answer 13

8-10 layers
Immune responses happen
Superficial to stratum basale

Question 14

Stratum granulosum

Answer 14

Middle of epidermis
3-5 layers
Keratinocytes undergoing apoptosis
Cells move away from nutrients = degeneration

Question 15

Stratum lucidum

Answer 15

Only in thick skin

4-6 layers of flattened clear dead keratinocytes

Question 16

Stratum corneum

Answer 16

25-30 layers of flat dead keratinocytes

Question 17

Callus

Answer 17

Abnormal thickening of stratum corneum
Caused by constant exposure of skin friction which stimulates increased keratin production from increased cell production

Question 18

Keratinization

Answer 18

New cells in stratum basale causing them to push towards the surface
Accumulating more and more keratin

Question 19

How Keratinized cells die off

Answer 19

New keratinocytes are produced
Pushing excess ones away and towards the surface and away from nutrient source causing them to die off.

Increase in rate as more epidermis layers are stripped
(Abrasions and burns)

Question 20

Psoriasis

Answer 20

Keratinocytes divide and move more quickly than normal from stratum basale to stratum corneum
Shed prematurely in as little as 7-10 days

Treatments: topical ointments
Ultraviolet therapy

Question 21

Dermis

Answer 21

Second deeper part of skin
Dense irregular connective tissue
Collagen and elastic fibers
Great strength

Question 22

Papillary region

Answer 22

1/5 of dermal layer
Thin collagen and elastic fibers
Surface area increased by dermal papillae 
Contain capillary loops 
And corpuscles (nerve ending)

Question 23

Reticular region

Answer 23

Attached to subcutaneous layer
Bundles of thick collagen fiber
Some adipose
Collagen fibers arranged netlike more regular than papillary region
Extensibility and elasticity

Question 24

Striae

Answer 24

Stretch marks Internal damage to dermis layer Skin is stretched too much Small dermal blood vessels ruptured

Question 25

Epidermal ridges

Answer 25

Ridges and grooves on palms, soles, etc. Straight lines or whorls Produced 3rd month fetal dvlpmt Increase surface area = increase sensitivity Ducts of sweat glands help to produce fingerprints

Question 26

Dermatoglyphics Tension lines

Answer 26

Study of pattern of epidermal ridges Line of cleavage Surgical incision parallel to collagen fibers will heal with only a fine scar

Question 27

Structural basis of skin color

Answer 27

Melanin, hemoglobin, carotene

Question 28

Albinism Vitiligo

Answer 28

Inherited inability to produce melanin loss of melanocytes from patches

Question 29

Skin color as diagnostic clue

Answer 29

Cyanotic - oxygen from lungs not getting to blood Jaundice - build up of yellow pigment bilirubin in skin Erythema - redness of skin, engorgement of capillaries in dermis Pallor - paleness of skin (shock, anemia)

Question 30

Hair

Answer 30

``` Dead Keratinized epidermal cells Shaft - above surface Root - deep in dermis Hair follicle - surrounds root Dermal root sheath - surround follicle Papilla of hair - indent bulb ```

Question 31

Arrector pili Hair root plexus

Answer 31

Smooth muscle, from superficial dermis of skin to dermal root sheath around the side of hair follicle 90* position, stimuli cause goosebumps Surrounds each hair follicle, generates nerve impulses

Question 32

Hair growth

Answer 32

Growth stage 2-6 years Regression stage 2-3 weeks Resting stage 3 months

Question 33

Types of hairs

Answer 33

Lanugo - fine no pigmented hairs Terminal hairs - replace lanugo prior to birth Vellus hairs - peach fuzz

Question 34

Sebaceous glands

Answer 34

Oil glands Connected to hair follicles Secreting portion lies in dermis usually opens in neck of hair follicle Secretes sebum Mix of triglycerides, cholesterol, proteins, inorganic salts

Question 35

Sweat glands | Sudoriferous glands

Answer 35

Eccrine sweat gland - most common | Apocrine - armpit, groin

Question 36

Nails

Answer 36

``` Free edge Nail body Lunula Nail root Hyponychium - secures nail ```

Question 37

Vitamin D

Answer 37

UV rays + precursor | Enzymes in liver and kidney modify to calcitriol

Question 38

Inflammatory phase | Deep wound healing

Answer 38

Blood clot Eliminate microbes Vasodilation permeability

Question 39

Migratory phase | Deep wound healing

Answer 39

Clot becomes scab Epithelial cells migrate to bridge wound Fibroblasts synthesize scar tissue Damaged blood vessels grow

Question 40

Proliferative phase | Deep wound healing

Answer 40

Epithelial growth continued growth of blood cells

Question 41

Maturation phase | Deep wound healing

Answer 41

Scab sloughs off Epidermis restored to thickness Blood vessels restored Collagen fibers organized

Question 42

Scar tissue

Answer 42

Formation : fibrosis Hypertrophic scar - raised above Keloid - extends boundaries Densely arranged collagen fibers Decreased elasticity Fewer blood vessels