Module 5

Question 1

what are the 3 layers of the skin

Answer 1

epidermis
dermis
hypodermis/subcutaneous layer

Question 2

epidermis

Answer 2

the superficial portion of the skin
avascular
4-5 layers of stratified squamous epithelium

Question 3

dermis

Answer 3

the deeper layer
primarily composed of CT

Question 4

hypodermis/subcutaneous

Answer 4

lies deep within the dermis
consists of areolar and adipose tissue
an area of fat storage, blood vessel passage, and pressure nerve endings

Question 5

what are the 5 layers of the epidermis

Answer 5

stratum corneum
stratum lucidum
stratum granulosum
stratum spinosum
stratum basale

Question 6

what cell type is found in stratum spinosum, granulosum, lucidum, and corneum?

Answer 6

keratinocytes

Question 7

keratin

Answer 7

an intracellular fibrous protein that gives hair, nails, and skin their hardness and water-resistant properties

Question 8

what are the 4 cell types in the epidermis

Answer 8

keratinocytes
melanocytes
langherans cells
merkel cells

Question 9

keratinocytes

Answer 9

produce keratin which helps protect the skin and underlying tissue from heat, microbes, and chemicals.

Question 10

what are lamellar granules?

Answer 10

produced by keratin
release a waterproof sealant

Question 11

melanocytes

Answer 11

produce melanin

Question 12

langherans cells

Answer 12

participate in immune responses

Question 13

merkel cells

Answer 13

touch a sensory structure called a tactile (merkel) disk, and function in the sensation of touch

Question 14

what are the 2 layers of the dermis

Answer 14

papillary
reticular

Question 15

papillary layer

Answer 15

areolar CT
contains fine elastic fibers, dermal papillae, corpuscles of touch (Meissners corpuscles), and free nerve endings for sensations of heat, cold, pain, tickle, and itch

superficial layer

Question 16

reticular layer

Answer 16

dense irregular CT
contains bundles of collagen fibers and some elastic fibers
well vascularized
has a rich sensory and sympathetic nerve supply

Question 17

what are the 3 pigments responsible for skin and hair colour

Answer 17

melanin
carotene
hemoglobin

Question 18

what are the 2 forms of melanin

Answer 18

eumelanin
pheomelanin

Question 19

eumelanin

Answer 19

black and brown

Question 20

pheomelanin

Answer 20

red

Question 21

the amount of melanin present in our skin is
dependent on

Answer 21

a balance between available sunlight and folic acid destruction, and protection from UV radiation and vitamin
D production.

Question 22

What structures constitute the integumentary system

Answer 22

Skin
Hair
Nails
Glands
Receptors

Question 23

functions of the skin

Answer 23

Maintain body temperature
Protection
Sensory perception
Excretion
Synthesis of vitamin D
Immunity
Broad reservoir

Question 24

3 parts of hair

Answer 24

shaft above the skin
root that penetrates the dermis and SC layer
hair follicle consisting of two epidermal layers surrounding the root

Question 25

what is hair composed of

Answer 25

outer cuticle inner medulla innermost cortex

Question 26

what is hair follicle made of

Answer 26

hair bulb hair papilla hair matrix

Question 27

hair function

Answer 27

protection thermal insulation sensing light touch

Question 28

3 glands associated with the skin

Answer 28

sebaceous (oil) glands sudoriferous (sweat) glands ceruminous glands (earwax)

Question 29

sebaceous glands location

Answer 29

usually connected to hair follicles absent in the palms and soles

Question 30

sebum

Answer 30

moistens hairs waterproofs and softens skin inhibits bacterial growth

Question 31

2 types of sudoriferous glands

Answer 31

apocrine sweat glands eccrine sweat glands

Question 32

apocrine sweat glands

Answer 32

limited to the skin of the axilla pubis and the areolae ducts open to hair follicles

Question 33

eccrine sweat glands

Answer 33

help to regulate body temperature through evaporation eliminate wastes such as urea

Question 34

cerumen

Answer 34

earwax

Question 35

stratum basale/stratum germinativum

Answer 35

single layer stem cells capable of cell division attached epidermis to basal lamina its function is to provide cells for the epidermis

Question 36

basal cells

Answer 36

cuboidal-shaped stem cells precursor to keratinocytes

Question 37

stratum spinosum

Answer 37

provides strength and flexibility to the skin spiny in appearance 8-10 layers of keratinocytes has a layer of langherans cells (fx as macrophages) keratinocytes in this layer release water-repelling glycolipids

Question 38

stratum granulosum

Answer 38

where a water repellent sealant forms between cells 3-5 layers cells are flatter, thicker membranes generates large amounts of keratin and keratohyalin

Question 39

stratum lucidum

Answer 39

present only in fingers, palms, and soles of feet keratinocytes are dead and flattened cells are densely packed with eleiden

Question 40

eleiden

Answer 40

a clear protein rich in lipids derived from keratohyalin stratum lucidum

Question 41

stratum corneum

Answer 41

most superficial layer 15-30 layers dead cells constant exposure to friction causes this layer to thicken and form a callus

Question 42

fx of stratum corneum

Answer 42

prevents penetration of microbes and the dehydration of underlying tissues provides mechanical protection against abrasion

Question 43

how long does it take for the stratum corneum to be replaced completely?

Answer 43

4 weeks

Question 44

dermal papillae

Answer 44

projections of the papillary layer of the dermis into the stratum basal of the epidermis

Question 45

What is the function of the arrector pili muscles

Answer 45

Arrector pili muscles pull the hairs into a vertical position. The contraction of the muscles occurs under the stresses of fright, cold, or emotion.

Question 46

Accessory structures of the skin include

Answer 46

hair glands nails

Question 47

Vitamin D production by the skin depends on

Answer 47

Exposure to ultraviolet radiation

Question 48

nerves and blood vessels are found mainly in the:

Answer 48

dermis