Chapter 5: The Integumentary System: Skin

Question 1

Epidermis

Answer 1

outermost superficial region

Question 2

Dermis

Answer 2

middle region

Question 3

Hypodermis

Answer 3

deepest region

Question 4

Stratum Basale

Answer 4

Deepest epidermal layer firmly attached to the dermis

a single row of the youngest keratinocytes undergo rapid mitosis

Question 5

Stratum Spinosum (prickly layer)

Answer 5

Cells contain a weblike system of intermediate filaments attached to the desmosomes
Melanin granules and langerhais cells are abundant

Question 6

Stratum Granulosum (granular layer)

Answer 6

thin; 4-5 cell layers, drastic changes in keratinocyte appearance occurs
keratohyaline and lamellar granules accumulate in these cells

Question 7

Stratum Corneum (horny layer)

Answer 7

outermost, 3/4 of epidermal thickeness, waterproofin, protection from abrasion/penetration, effective barrier from biological, chemical, and physical assaults

Question 8

Dermis

Answer 8

2nd major skin region w/ strong, flexible connective tissue, cells: fibroblasts, macrophages, mast cells, white blood cells, composed of papillary and reticular
reticular layers contain sweat and sebaceous glands

Question 9

Papillary layer

Answer 9

areolar connective tissue w/ collagen and elastic fibers, dermal papillae- peglike projections, friction ridges originate here

Question 10

Reticular layer

Answer 10

80% of thickness of skin, dense fibrous connective tissue, collagen fibers add strength/ resiliency, elastic fibers provide stretch-recoil properties

Question 11

Sweat glands

Answer 11

different types, secrete sweat help prevent overheating of the body, cerumen or milk

Question 12

Eccrine sweat glands

Answer 12

found in the palms, soles of the feet, and forehead

Question 13

Apocrine sweat glands

Answer 13

found in axillary and anogenital

Question 14

Ceruminous glands

Answer 14

modified apocrine glands in external ear canal that secrete cerumen (ear wax)

Question 15

Mammary glands

Answer 15

specialized sweat glands that secrete milk

Question 16

Sebaceous glands

Answer 16

simple alveolar holocrine glands found all over the body
hormones (androgens) can stimulate secretion
secrete oil substance called sebum which helps soften and lubricate skin, bacteriostatic

Question 17

Hypodermis

Answer 17

subcutaneous layer deep to the skin

composed of adipose and areolar connective tissue

Question 18

Melanin

Answer 18

yellow to reddish-brown to black pigment, responsible for dark skin colors

Question 19

Carotene

Answer 19

yellow to orange pigment, most obvious in the palms and soles of feet

Question 20

Hemoglobin

Answer 20

red protein in red blood cels responsible for the pinkish hue of the skin

Question 21

Nails

Answer 21

scalelike modification of the epidermis on the distal, dorsal surface of fingers and toes
hard “keratin” produced by cells of the nail matrix

Question 22

Hair

Answer 22

dead keratinized cells produced by hair follicles
contain hard keratin
made up of the shaft projecting from the skin, and root embedded in the skin
core of medulla and a cortex and outermost cuticle
pigmented by melanocytes at base

Question 23

Root Hair plexus

Answer 23

knot of sensory nerve ending that wraps around each hair bulb, hair acts as sensitive touch receptors

Question 24

Functions of Hair

Answer 24

maintain warmth, alerting body to presence of insects on skin, protect the scalp

Question 25

Vellus Hair

Answer 25

pale, fine body hair found in children and females

Question 26

Terminal Hair

Answer 26

coarse, long hair of eyebrows, scalp, axillary, and pubic regions, armpits

Question 27

Alopecia

Answer 27

hair thinning in both sexes

Question 28

True (frank) baldness

Answer 28

genetically determined and sex-influenced condition

Question 29

Male pattern baldness

Answer 29

caused by change in follicular response to DHT

Question 30

Skin Functions

Answer 30

Protection: chemical, physical, mechanical barriers
Body Temperature: dilation (cooling) or constriction (warming) dermal blood vessels
Cutaneous sensation: exoreceptors sense touch and pain
Metabolic function: synthesis of vitamin D in dermal bloos vessels
Blood reservoir: skin blood vessels store up to 5% of the body’s blood volume
Excretion: limited amounts of nitrogenous wastes (urea) and water are eliminated via sweat

Question 31

Basal cell carcinoma

Answer 31

least malignant, most common (80%)
stratum basal cells proliferate and invade the dermis and hypodermic, slow growing, do not metastasize, cured by surgical excision in 99% of cases

Question 32

Squamous cell carcinoma

Answer 32

arises from keratinocytes of stratum spinosum, mostly on the scalp, ears and lower lip, grows rapidly and metastasizes if not removed, prognosis good

Question 33

Melanoma

Answer 33

cancer of melanocytes, most dangerous, highlymetastatic, resistant to chemotherapy
asymmetry, border, color, diamete

Question 34

First degree burns

Answer 34

only epidermis is damaged

redness, swelling, pain

Question 35

Second degree burns

Answer 35

epidermis and upper regions of dermis are damaged
blisters appear
heeling takes weeks, no scarring if no infection

Question 36

Full thickness burns

Answer 36

Third-degree
entire thickness of skin is damaged
gray-white, cherry red, or black
no initial edema or pain (nerve endings destroyed)
skin grafts are usually required to restore the integument

Question 37

Lanugo

Answer 37

downy coat of delicate hairs covering fetus

Question 38

Vernix casseosa

Answer 38

waxy substance produced by sebaceous glands that protects the skin of the fetus in amniotic fluid

Question 39

Adolescence to adult

Answer 39

skin and hair become oiler and acne may appear
skin starts showing effects of cumulative environmental assaults around age 30
scaling and dermatitis become more common

Question 40

Older age

Answer 40

epidermal replacement of cells, skin becomes thinner
itchy and dry skin (dec. sebum)
subcutaneous fat layer thins (cold unbearable)
Dec elasticity, loss of subcutaneous tissue- wrinkles
more susceptible to skin cancer, less hair follicles