Science Olympiad Supp. Integumentary Info

Freckles

Flat melanized patches vary with heredity or exposure to sun

Flexion Lines

On flexor surfaces of digits, palms, wrists, elbows, etc.- skin is tightly bound to deep fascia at these points

Friction Ridges

Markings on fingertips characteristic of primates; allow us to manipulate objects more easily- fingerprints are friction ridge skin impressions

Moles

Elevated patches of melanized skin, with out without hair

Serous Membrane

Line body cavities that have no opening to the outside; secrete a watery fluid that lubricates surface

Mucous Membranes

Line cavities and tubes that open to the outside

Synovial Membranes

Form the inner lining of joint cavities; secrete a thick fluid

Epidermis

Covers internal and external surfaces of body

Dermis

Contains accessory skin structures

Subcutaneous Layer

Attaches skin to underlying tissues and organs

Thin Skin

Covers most of body; 1-2mm thick; hairy, covers all parts of body except palms, soles

Thick Skin

Up to 6 mm thick on palms of hands and soles of feet; hairless; covers palms and soles

Eyelid Skin

0.5 mm thick

Keratinocytes

90% of epidermal cells; protects and waterproofs the skin

Melanocytes

8% of the epidermal cells produce melanin and absorb UV light

Langerhans Cells

Arise from red bone marrow and migrate to the epidermis; constitute small portion of epidermal cells; participate in immune responses; easily damaged by UV light

Merkel Cells

Least numerous of epidermal cells; found in deepest layer of epidermis; along w/ tactile disks, function in touch sensation

Stratum Corneum

Nuclei and organelles are destroyed by lysosomes and the cells fill with keratin

Stratum Lucidum

Only found in thick skin; 3-5 layers of clear, flat, dead keratinocytes- dense packed intermediate filaments; thick plasma membranes

Stratum Granulosum

Cells start to become keratinized- secrete lipid-rich secretion that acts as a water sealant

Stratum Spinosum

8-10 layers of keratinocytes; strength and flexibility

Stratum Basale

Stratum germinatum; new cells are formed

4 weeks

How long it takes for skin to be replaced

Papillary layer

surface area increased due to dermal papillae which contains capillaries or tactile receptors; epidermal ridges conform to papillae

Reticular Layer

Contains hair follicles, nerves, sebaceous and sudoriferous glands

Hypodermis

Not part of skin; contains connective tissue and fat for insulation; less in infants and elderly (cold sensitive)

Albinism

Lack of skin pigment

Sunlight

Environmental Factor impacting skin color

Melanocytes

All humans have same amt of …

Hemoglobin

what factor in blood affects skin color

Pheomelanin

reddish yellow pigment

eumelanin

brownish black pigment

melanosomes

organelles that produce melanin

increased enzyme activity

what affects does uv light have on melanosomes

eumelanin

protects from uv radiation (type)

pheomelanin

breaks down from uv radiation

carotene

yellow orange pigment; precursor to vitamin a; important for vision

Hemoglobin

oxygen carrying pigment in rbcs

decreases

how does stem cell activity change with aging

thin skin, slow repair

2 effects of declining stem cells

decrease

how do epidermal dendritic cells change as skin ages

reduced immune response

effect of decreased epidermal dendritic cells

declines

how does vitamin d3 production change with aging

calcium absorption decreases, brittle bones

effects of declining vitamin d3 synthesis

declines

how does glandular activity changes with age

skin dries, overheating

2 effects of decline in glandular activity

declines

blood supply changes with age, makes you feel cold

die

hair follicles …. with age

thins, less elastic, wrinkles

3 effects on dermis of aging

skin derivatives

during embryonic development, small epidermal cells from stratum basale push down into dermis and form hair follicles and glands

hair

help in sensing light touch due to touch receptors on root plexuses

shaft

portion of hair that projects from skin surface

root

portion of hair deep to the shaft penetrating dermis; medulla, cortex, cuticle

bulb

houses papilla which contains the blood vessels that nourish the growing hair follicle

matrix

responsible for hair growth and produces new hair

hair root plexus

dendrites of neurons sensitive to touch

100,000

number of hairs on scalp

wavy

oval shaped hair produces ….. hair

curly

flat shaped hair produces ….. hair

straight

round shaped hair produces ….. hair

5 million

number of hairs on adult body

anagen

growth phase of hair

catagen

transitional phase of hair

telogen

resting period

sudoriferous glands

sweat glands

eccrine

secretes cooling sweat

apocrine

secretes during stress/excitement

sebaceous

oil glands

acne

inflammation of sebaceous gland ducts

ceruminous

modified sweat glands of external ear produce wax

nails

packed, hard, keratinized epidermal cells

nail body

portion of nail that is visible

free edge

part that extends past the distal end of the digit

nail root

portion buried in a fold of skin

lunula

half moon- crescent shaped area of the nail

hyponychium

secures nail to the fingertip- thickened stratum corneum

eponychium

cuticle; narrow band of epidermis- growth of nails in the nail matrix

Herpes simplex, warts, cold sores

Viral Skin Infections 3

bioles, carbuncles, impetigo

bacterial skin infections

Irritant Dermititis

soaps, detergents, shampoos

allergic dermititis

poison ivy, poison oak, gloves, metals, fragrances

psoriasis

chronic, noninfectious skin disease, skin becomes dry and scaly, often with pustules and many varieties, stratum corneum gets thick and dead, cells accumulate, often triggered by trauma, infection, hormonal changes, or stress

Vitiligo

an autoimmune pigmentation disorder where melanocytes in the epidermis are destroyed

basal cell carcinoma

spread uncommon, very curable if found early

Squamous cell carcinoma

occurs in parts exposed to the sun

malignant melanoma

most common where ozone layer is thin, deadly if not caught early