INTEGUMENTARY READING NOTES

Melanosome

vesicle for melanin transfer

Melanin produced in what layer

Stratum basale

why is tanning temporary

Lysosomes destroy melanosomes, sloughing off skin

Disorders of skin (genetic/melanin)

albinism, vitiligo, jaundice, addisons (bronze)

Temporary Disorders of skin caused by

drop in oxygen (temporary - white; prolonged - blue of cyanosis)

Sudoriferous glands

Sweat, merocrine

Eccrine gland (coiled)

deep in dermis, palms of hands, feet, forehead

Aprocrine gland

hairy, deep in dermis even to hypo

Hair grows from the

hair matrix, basale (Cell factory)

arrector pili muscle

contracts when sensory on hair, causes sympathetic fight/flight response (automatic/invol)

Hair growth stages

Anagen (cell growth, basale factory); catagen; telogen (hair at rest, til next anagen)

Living hair cells located on the

hair bulb

Layers of Epidermis

Corneum, lucidum, granulosum, spinosum, basale

Corneum

1. Superficial layer exposed to outside

2. 15-30 layers of dead cells (DRY)

   1. Mechanical protection

3. Shed quickly; replaced in 4-6 weeks

Lucidum (only in thick skin)

1. Smooth, translucent, 3-5 thin layers

2. Dead, flat keratinocytes

Granulosum

3-5 layers with keratin + keratohyaline, hair and nail structures here

Basale

Single row of cuboidal stem, constantly doing mitosis

What other cells in basale

Merkel (pressure,texture), Melanocytes,

Fingerprints form in and from

basale AND dermis papillary layer

What other cells in spinosum

Langerhans (immune cells)

Merkel

Pressure, texture

Dermis layers

Papillary, reticular

Papillary layer in dermis formed from

Areolar connective tissue forms loose mesh (loose, connective)

Reticular layer in dermis formed from

Dense, irregular tissue

Papillary layer in dermis

contains lymphatic, nerve fibers, meissner corpuscles (light touch)

meissner corpuscles

(light touch)

Reticular layer does what

Elasticity, collagen for strucure, keeps skin hydrated, fat storage

Hypodermis purpose

Protects underlying fascia of bones and muscles

Hypodermis components

Loose, areolar connective tissue + adipose tissue

Nails

Grow from nail root, cuticle seals nail for protection, nail folds keep in place, hyponychium germ barrier, nail edge is dead cells (corneum)

Nail root is what layer of skin

epidermis; basale = continuous growth

Hyponychium

germ barrier under nail edge

Sudoriferous Glands

Merocrine gland, produce sweat to cool down body

Merocrine gland

Secretes through vessicles; membrane reforms

Eccrine Gland

Deep in dermis, found on hand, feet, forehead

Aprocrine gland

Hairy regions, deep in dermis

What causes smelly odor

compounds decomposing

Sebaceous glands function

lubricates and makes skin waterproof, antibacterial, prevent water loss

Sebum is

fats that lubricate dry/dead layer of corneum; starts in puberty

Thermoregulation

sympathetic nervous system (fight or flight) stimulates sweat glands

Artelioles dilate vs constrict

skin red, heat spreads; skin white, minimizes heat loss

As we age

less mitosis (basale), less structure in hypodermis (saggy skin), less regeneration (slow wound healing), thinner hair, nails, less immunity in cells

Pacinian corpuscle

vibration

Rickets

misshapen bones from lack of calcium (vit D issue)

osteomalacia

softening of bones (older folks) (vit D)

Basal cell carcinoma

Basale → migrate to bump on skin from long-term sun

Squamous cell carcinoma

Affects keratinocytes (spinosum), metastasizes

Melaoma

mole → uncontrolled melanocyte growth; highly metastic

Melanoma markers ABCDE, EFG

Asymmetry, borders, color, diameter, evolving, elevated, firm growing

Burns cause

death of skin cells, loss of fluid

1st degree burn

epidermis only, sunburn

2nd degree burn

epidermis + dermis, blistering

3rd degree and 4th degree burn are

less painful from sensory receptor loss

3rd degree burn

hits nerve endings, appears white/red/black

4th degree burn

hits muscle/bone - grafting, amputation

scabs

collagen-rich skin created from fibroblasts

keloids

raised or hypertrophic from overproduced scar tissue

atrophic

sunken scar

necrosis

tissue death

calluses

basale stem cells triggers thicker skin for protection against constant abrasian

corn

specialized callus