a&p unit 3: dermatology

cut-

skin

derm-

skin

epi-

upon

follic-

small bag

kerat-

horn

melan-

black

seb-

grease

integumentary system functions

temperature regulation, protection from chemicals and pathogens, sensory functions, vitamin D production, prevents water loss 

epidermis

outermost skin layer

tissue found in epidermis

stratified squamous

keratinization

cells hardening as they are filled with the waxy protein, keratin

fifth/top layer of epidermis

stratum corneum

stratum corneum

outermost layer of epidermis, oldest cells, dead epithelial cells filled with keratin, “dead flat bags”

fourth layer of epidermis found in soles and palms only

stratum lucidum

stratum granulosum

3-5 layers of flattened granular cells (filled with keratin)

third layer of epidermis

stratum granulosum

second layer of epidermis

stratum spinosum

stratum spinosum

many layers of rounded cells with large nuclei

first/bottom layer of epidermis

stratum basale

stratum basale

above basement membrane, single row of cuboidal cells undergoing mitosis, composed of melanocytes

melanocytes

produce the pigment melanin

melanin function

determines skin color and absorbs UV radiation

dermis

inner layer

tissues in dermis

glandular ET, dense irregular, smooth muscle, nervous tissue, and blood vessels

where is the hair follicle found

in the dermis

function of the dermis

binds epidermis to underlying tissue, location of glands, hair, and nails

hypodermis/subcutaneous

bottom layer

tissues in hypodermis

adipose and blood vessels

hypodermis function

insulation

arrector pili muscle function

causes hair to stand erect

where is the hair root located

the deep dermis

what are the cells in the hair root doing

performing mitosis, maturing and accumulating keratin

three parts of hair root

medulla, cortex, cuticle

medulla

the central core of the hair

cortex

the middle layer of hair, providing strength and color

cuticle

the outermost layer of the hair, protecting the inner layers from damage

hair sheaths

cover hair root

epidermal sheath

a layer of cells that surrounds the hair follicle, providing support and nourishment

dermal sheath

the layer of connective tissue surrounding the hair follicle and providing support

what tissue is the dermal sheath made of

dense irregular

where is the hair shaft located

above the skins surface

tissue found in nails

keratinized epithelium

where does mitosis happen in the nail

lunula

lunula

the visible half-moon area at the base of the nail where new cells are produced

merocrine sweat glands location in skin

coil in deep dermis

merocrine sweat glands characteristics

respond to temperature/exercise, no odor

merocrine sweat glands usually secrete where?

forehead, neck, back

merocrine sweat glands secrete what?

water, salts, and wastes

apocrine sweat glands location in skin

ducts terminate into hair follicles

apocrine sweat glands characteristics

respond to stress/emotions, odor due to bacteria, active at puberty

apocrine sweat glands usually secrete where?

armpits, groin

what do apocrine sweat glands secrete?

sweat, oil, cell debris, “milky”

ceruminous glands

ear, secrete wax

sebaceous gland location

found all over the body except palms and soles

what do sebaceous glands secrete

sebum; oil

sebum

bactericidal oil, keeps skin and hair soft and waterproof

first degree burn

a minor burn that affects only the epidermis, causing redness and minor pain

second degree burn

a burn that affects the epidermis and part of the dermis, causing pain, swelling, and blistering

third degree burn

a severe burn that affects all layers of skin, causing destroyed tissue and numbness due to nerve damage

what burn causes blisters

Second degree burns

acne

accelerated sebaceous activity during adolescence

birthmark

blemish or spot on the skin, visible at birth

dermatitis

skin inflammations that increase with frequency with age

psoriasis 

skin disease characterized by red patches covered with scales

lanugo

fine, soft hair that covers the body of a fetus

pustule

elevated pus-filled area on skin

mole

skin tumor that is usually pigmented

what type of gland is ceruminous?

A type of sweat gland that produces earwax

layer of translucent cells, absent in thin skin

Stratum lucidum

layers of the epidermis containing mostly or all dead cells?

Stratum corneum and lucidum

vascular region of skin

dermis

site of elastic and collagen fibers in skin

dermis

what layer of skin is melanin formed in?

stratum basale 

where do derivatives (hair, nails) reside?

dermis

the stratum germinativum?

stratum basale

what factors cause the natural demise of the epidermal cells?

Inadequate nutrient supply, exposure to UV radiation, accumulation of keratin, water loss, and natural aging processes

what causes skin cancer

uncontrollable growth of mutated cells

most common form of skin cancer

basal cell carcinoma 

what UV ray is the hardest to block

UV-A

what UV ray is blocked by the ozone layer

UV-C

what does SPF stand for

sun protection factor

a sunburn is considered which degree of burn?

first degree burn

what form of skin cancer is the deadliest 

melanoma

what does squamous cell carcinoma look like

red, scaly bump

what does basal cell carcinoma look like

shiny, waxy bumps

what does melanoma look like

dark, irregular moles or spots

where is melanoma found in skin

melanocytes