more on integumentary system

Question 1

important functions of the skin

Answer 1

covering, waterproof, barrier from foreign invasions, protection from UV, heat control, sensory receptors, vitamin D production and excretion

Question 2

how does the skin protect from UV rays

Answer 2

melanocytes produce melanin that also absorbs UV light
-UV damage is a cause of cancer

Question 3

skin is the ______ organ

Answer 3

largest

Question 4

what are the layers of the skin (superficial to deep)

Answer 4

epidermis, dermis, and hypodermis

Question 5

epidermis

Answer 5

consists of squamous epithelial cells and dead cells
-thickest where there is abrasion

Question 6

squamous epithelial cells

Answer 6

stratified into 5 layers and keratinized (no nucleus)

Question 7

dead cells

Answer 7

filled with keratin (protein), constantly shed (desquamation) and replaced

Question 8

what is the deepest layer of the epidermis called

Answer 8

stratum germinativum

Question 9

importance of the stratum germinativum

Answer 9

cells divide here
-contains melanocytes

Question 10

dermis

Answer 10

dense connective tissue
-contains blood vessels, nerves, lymph, smooth muscle, sweat glands, hair follicles, and sebaceous glands

Question 11

dense connective tissue

Answer 11

collagenous and elastin fibers

Question 12

hypodermis

Answer 12

subcutaneous, fatty tissue adipose
-attaches dermis to muscle or bone

Question 13

what are the two main accessory structures of the skin

Answer 13

hair and nails

Question 14

hair

Answer 14

the shaft is visible and the root is within the epidermis in a hair follicle
-follicle is within epidermis and dermis
-contains arrector pilli muscle, follucle, papilla, sebaceous glands, and adipose

Question 15

nails

Answer 15

modification of leathery epidermal cells with hard keratin
-air mixed with keratin makes lunula (crescent point at proximal end)
-nail root within nail bed is where growth occurs

Question 16

sebaceous glands

Answer 16

along wall of hair follicles
-produces sebum
-controlled by the endocrine system

Question 17

sweat glands

Answer 17

to cool and secrete minimal waste
-tubular (twisted) glands in most parts of skin
-sweat contains sodium chloride, urea, uric acid, and ammonia

Question 18

apocrine sweat glands

Answer 18

within armpits and around genitalia

Question 19

where are sweat glands most abundant

Answer 19

palms of hands and soles of feet

Question 20

ceremonious glands

Answer 20

modified apocrine sweat glands with contributions from sebaceous glands
-lubrication and protection within ear canal
-only within dermis of the external auditory canal

Question 21

melanoma

Answer 21

a type of skin cancer
-most dangerous
-least common
-ABC’s

Question 22

what are the ABC’s for melanoma

Answer 22

A : asymmetry
B : border that are uneven vs smooth (melanoma vs. benign)
C : color variety or change
D : diameter that is relatively large
E : evolving, changing in size, shape, elevation, color, etc.

Question 23

waardenburg syndrome

Answer 23

genetic and congenital condition
-mutation that changes melanocytes
-changes of pigmentation os skin, hair and eyes
-can have moderate to profound HL

Question 24

dermatomes

Answer 24

an area of skin supplied by a single afferent spinal nerve (from a single dorsal root)
-carries certain information to a particular point

Question 25

myotomes

Answer 25

segmental muscular nerve supplies overlap
-within most large muscles
-similar to dermatomes but with muscles

Question 26

sclerotomes

Answer 26

one of the bony, cartilaginous, or membranous portions which separates the myotomes
-connective tissue that separates muscles

Question 27

cutaneous receptor distribution

Answer 27

not uniform
-areas may be densely innervated than other areas (such as lips and fingertips)
-can test by two point discrimination

Question 28

excretion

Answer 28

electrolytes excreted when levels are high in blood
-composed of lactic acid, urea, uric acid and ammonia (metabolic waste)

Question 29

vitamin D

Answer 29

UV promotes skin production of a precursor to vitamin D
-needed for absorption of calcium and phosphorus within GI tract
-calcium for muscle contraction and bone growth

Question 30

dermatitis

Answer 30

skin inflammation or infection

Question 31

psoriasis

Answer 31

red patches, thick, scaly, may bleed, hyperactive stratum germinativum
-occurs due to pushing up too many new cells

Question 32

warts

Answer 32

uncontrolled growth in epidermal layer
-human papillomavirus

Question 33

cold sores

Answer 33

fluid filled blister
-herpes simplex virus

Question 34

impetigo

Answer 34

small blisters
-staphylococcus aureus bacteria
-highly contagious (face and can spread)

Question 35

furuncle or boil

Answer 35

staph infection of hair follicle or gland with pus

Question 36

urticaria or hives

Answer 36

localized edema in epidermis
-elevated, red or pale and itchy

Question 37

external otitis

Answer 37

infection in ear canal
-bacterial or fungus

Question 38

swimmer’s ear

Answer 38

type of external ear canal infection
-typically bacterial

Question 39

otomycosis

Answer 39

fungal infection

Question 40

necrotizing external otitis

Answer 40

the eating away of the skin or even bone within the ear canal

Question 41

thermoregulation

Answer 41

sweating occurs to reduce hyperthermia
-a vascular change (autonomic)
-vasodilation and vasoconstriction

Question 42

vasodilation

Answer 42

smooth muscle in blood vessels of the skin relax/open to allow more blood to enter the skin
-blood transports heat which this pulls heat away from the body core to the surface
-hot water example
-skin may look pink/red

Question 43

vasoconstriction

Answer 43

contraction of arrector pili to trap air and make insulation layer of smooth muscle in blood vessel of the skin to reduce blood flow to keep heat in
-cold water example

Question 44

sensation receptors

Answer 44

senses the external environment (touch, pressure, vibration, temperature, and pain)
-picks it up and sends it to the CNS