Chapter 4 - Integumentary System

Question 0

Epidermis

Answer 0

Protects dermis from trauma
Controls skin permeability, prevents water loss
Prevents entry of pathogens
Synthesizes vitamin D
Sensory receptors detect touch, pressure, pain, and temperature
Coordinates immune response to pathogens and skin cancers
Stratified squamous cells, avascular, protective shield

Question 1

Integumentary system

Answer 1

Composed of the skin and it’s derivatives; hair, nails, sweat glands, mammary glands

Question 2

Dermis

Answer 2

Papillary layer - nourishes and supports dermis
Reticular layer - store lipid reserves
Tough leathery layer
Vascular
Origin of accessory structures 
Inner layer

Question 3

Stratum basale

Answer 3

Deepest layer
Mitotic cells
Firmly attached to the basal lamina that separates the epidermis from the loose connective tissue of the adjacent dermis
Contains epidermal stem cells, merkel cells, melanocytes

Question 4

Stratum spinosum

Answer 4

Infrequent mitosis
Several cells thick
Melanocytes
Some keratinocytes

Question 5

Stratum granulosum

Answer 5

Keratinization begins
Distant from basement membrane and blood supply
All cells posses a nucleus
Gradually the cell membranes thicken, organelles disintegrate, cells die

Question 6

Stratum lucidum

Answer 6

Clear layer
Present only in thick skin
Glassy
Cells lack organelles and nuclei, are flattened, densely packed, filled with keratin filaments that are oriented parallel to the surface of the skin

Question 7

Stratum corneum

Answer 7

Outermost layer
Multiple layers of dead, flattened, interlocking keratinocytes
Relatively dry
Permits slow water loss by insensible perspiration

Question 8

Process of keratinization

Answer 8

Division and pushing to outside

Question 9

Dermis - basic tissues

Answer 9

Gel like matrix - loose connective tissue
Dense connective tissue - collagen fibers, elastic fibers, reticular fibers
Adipose tissue - subcutaneous later

Question 10

Dermis - papillary layer

Answer 10

20%
Responsible for giving epidermis blood supply
Loose connective tissue
Superior surface called dermis papillae
Blood vessels and nerves
Produces epidermal ridges - fingerprints

Question 11

Dermis - reticular layer

Answer 11

80%
Dense irregular connective tissue
Elastin
Collagen

Question 12

Lines of cleavage

Answer 12

Protein fibers of dermis run in parallel lines

Incision parallel to lines of cleavage do not gape open and are more likely to heal

Question 13

Wrinkles

Answer 13

Reduced thickness and flexibility of the dermis produces wrinkles and sagging skin

Question 14

Carotene

Answer 14

Orange yellow pigment found in various orange colored veggies
Can be converted to vitamin A which is required for epithelial maintenance and the synthesis of visual pigments by the photoreceptors of the eye

Question 15

Melanin

Answer 15

Produced and stored in melanocytes
Forms in intracellular vesicles called melanosomes
Color the keratinocytes temporarily until the melanosomes are destroyed by lysosomes

Question 16

Hair and hair follicles

Answer 16

Hair follicle almost to subcutaneous layer
hairs are non living structures that are formed in organs called hair follicles
Hard and soft keratin
Arrector pili muscle

Question 17

Nails

Answer 17

Protect and support tips of fingers and toes
Epidermal cells
Hard keratin
Basal layer - producing nails

Question 18

Sebaceous glands

Answer 18

Cuboidal epithelium
Secrete waxy, oily sebum
Acne
Seborrheic dermatitis 
Provide lubrication and antibacterial action

Question 19

Sweat glands (sudoriferous)

Answer 19

Cuboidal
99% water
Sodium chloride
Urea, uric acid, ammonia

Question 20

Age related skin changes

Answer 20

Delayed healing
Epidermal and dermal thinning
Increased risk of infection and sun damage
Decrease vitamin D synthesis
Decreased melanocyte activity
Diminished blood supply
Decreased glandular activity

Question 21

Striae

Answer 21

Stretch marks
When the elastic capabilities of the skin are exceeded, elastic and collagen fibers break, and since the skin does not recoil the skin then wrinkles creating a network of stretch marks

Question 22

Skin cancer - basal cell carcinoma

Answer 22

Least malignant
Rarely metastasizes 
Cause = UVR in about 75% of skin cancers
Originates in stratum basale
Cancer appears in areas subjected to chronic UV exposure 
Linked to inherited gene

Question 23

Skin cancer - squamous cell carcinoma

Answer 23

Stratum spinosum
Cause = UVR
Totally restricted to areas of sun exposed skin
Treatment involves surgical removal of the tumor
Metastasis seldom occurs in SCC and almost never in BCC

Question 24

Skin cancer - malignant melanoma

Answer 24

``` Melanocytes 5% of skin cancers Leading cause of death in skin cancers Extremely dangerous Cancerous melanocytes Grow rapidly and metastasize throughout the lymphoid system ```

Question 25

Acne - skin disorder

Answer 25

Sebaceous ducts become blocked and secretions accumulate, causing inflammation and providing a fertile environment for bacterial infection

Question 26

Decubitus ulcers - skin disorder

Answer 26

Goes almost all the way to the bone Heel - patient who is bed ridden, no blood flow to heel Elbows, coccyx, scapula, heels Bed-sores