Science Olympiad Integumentary System

melanin

provides protection from UV damage

human defensin

natural antibiotic in skin

cathelicidins

proteins that prevent Step A infection in wounded skin

langerhans' cells

Found in Stratum Spinosum; React to antigens that cross broken skin & initiate and immune response (associated with immune system- beneficial because it catches bacteria as it enters skin)

serous membranes

line body cavities that have no opening to the outside

serous

serous membranes secrete a water fluid called ______ fluid that lubricates surfaces

mucous membranes

line cavities and tubes that open to the outside

synovial membranes

form the inner lining of joint cavities

synovial

synovial membranes secrete a thick fluid called ______ fluid

cutaneous membrane

what type of membrane in also known as skin

thin

what type of skin is hairy, covers all parts of the body except hands and feet

thick

what type of skin is hairless, covers hands and soles of feet, has epidermal ridges from well developed dermal papillae

keratinocytes

90% of epidermal cells, contains keratin, protects and waterproofs the skin

Langerhans cells

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

merkel cells

least numerous of epidermal cells, found in stratum basale, function in the sensation of touch

stratum corneum

25-30 layers of dead flat keratinocytes, shed continuously and replaced by cells from deeper strata, serves as a water microbe, injury barrier

melanocytes

8% of epidermal cells, produces melanin, contributes to skin color and absorbs UV light

stratum lucidum

present only in thick skin, 3-5 layers of clear flat dead keratinocytes, has dense packed intermediate filaments and thick plasma membranes

stratum granulosum

3-5 layers of flattened keratinocytes undergoing apoptosis, marks the transition between deeper metabolically active strata and dead cells of superficial strata

stratum spinosum

8-10 layers of keratinocytes, cells have spine-like projections that tightly joins cells together, provides skin both strength and flexibility

stratum basale

deepest layer of the epidermis, contains stem cells, single row of cuboidal or columnar keratinocytes

Dermis

second deepest part of the skin, contains blood vessels, nerves, glands and hair follicles, composed of collagen and elastin

collagen

_______ fibers make up 70% of the dermis and give structural toughness and strength

elastin

_______ fibers are loosely arranged in all directions and give elasticity to the skin

Papillary and reticular layer

What are the layers of the dermis

papillary layer

superficial portion of the dermis, consists of areolar connective tissue containing elastin fiber, surface area increased due to projections called dermal papillae

reticular layer

deeper portion of dermis, consists of dense irregular connective tissue containing collagen/elastin fibers, contains hair follicles, nerves, and sebaceous and sudoriferous glands

hypodermis

attaches skin to underlying organs tissues, not part of the skin, contains connective and adipose tissue, infants and elderly have less of this which makes them sensitive to cold

albinism

inherited trait where a person cant produce melanin.

tyrosinase

albino people have melanocytes but are unable to make _______, an enzyme that initiates melanin production

cyanotic

appearance of skin when someone has stopped breathing and the skin appears bluish because the depletion of oxygen in hemoglobin

jaundice

caused by the build up of bilirubin in the blood which gives a yellowish appearance of eyes and skin, indicating liver disease.

bilirubin

yellow pigment produced by broken down red blood cells that is normally processed in the liver.

erythema

Abnormal redness of the skin resulting from dilation of blood vessels (as in sunburn or inflammation)

pallor

paleness, emotional state, anemia, low blood pressure causes what type of appearance

bronzing

metallic appearance; sign of Addison's disease, hypofunction of the adrenal cortex

hematoma

A localized swelling filled with blood under skin

leathery skin

overexposure clumping of elastin fibers

photosensitivity

abnormally high sensitivity to sunlight

genetics, environment, volume of blood

skin color can be caused by ________, ___________, and ________ ____ _____.

melanin, carotene, hemoglobin

what are the three pigments responsible for skin color

tyrosine

melanocytes synthesize melanin from the amino acid ________

eumelanin

melanin that is brownish black

pheomelanin

melanin that is reddish yellow

carotene

yellow-orange pigment and precursor for Vitamin A which is used to make pigments needed for vision. found in stratum corneum and fatty layers of dermis and hypodermis

hemoglobin

oxygen-carrying pigment in red blood cells

friction ridges

marking on fingertips, characteristics of primates, allow us to manipulate objects more easily

flexion lines

parts of digits, palms, wrists, elbows where skin is tightly bound at these points

meissner's corpuscles

enclosed in a capsule of connective tissue. react to light touch on palms, soles, lips, eyelids, external genitals, and nipples.

pacinian corpuscles

sense pressure and vibration changes deep in skin. every square centimeter of skin contains 14 of these

pain receptors

skin receptors that register pain and are the most numerous receptors at 200 per square centimeter

cold receptors

perceive cold sensations when the surface of the skin drops below 95 degrees F. 6 per square centimeter

hot receptors

perceive hot sensations when the surface of the skin is above 86 degrees F. 1 per square centimeter

thermoreceptors

found all over the body, contains hot and cold receptors but cold receptors are found in greater density

shaft

portion of hair that projects from skin surface

root

portion of hair deep to the shaft penetrating the dermis. has three layers medulla, cortex, and cuticle

medulla

most inner part of hair. contains pigment granules and air spaces

cortex

middle layer in hair and in dark hair contains pigment and in gray hair contains air bubbles

cuticle

outer layer of hair. heavily keratinized cells that lie like shingles

bulb

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

matrix

responsible for hair growth and produces new hair

arrector pili

smooth muscle, extends from dermis to the side of hair follicle, hair grows at an angle to surface of skin, _______ _____ muscles contract and pulls hair straight causing goosebumps

hair root plexus

free nerve endings wrapped around hair follicle; detects hair movement

anagen

hair growth phase

catagen

hair transitional phase where hair shrinks to 1/6 its size

telogen

hair does not grow and soon falls off

dark hair

hair that contains true melanin

blond and red hair

hair that has variants of melanin in which there is iron/sulfur

tyrosinase

gray hair results from a decline in _____

sudoriferous glands

sweat glands

eccrine sweat glands

Secreting glands, are far more numerous and are abundant on palms, soles of feet and forehead. Each is a simple, coiled, tubular gland. Ducts connect to pores. Sweat: 99% water, NaCl, vitamin C, antibodies, dermcidin and metabolic wastes.

appocrine sweat glands

glands stimulated during stress, secretes into hair follicle, contains lipids and proteins, referred as "cold sweat"

sebaceous glands

oil glands, connected to hair follicles, not on palms and soles

sebaceous glands

what keeps skin soft and pliable

acne

inflammation of sebaceous gland ducts

ceruminous

modified sweat glands of the external ear that produce ear wax

nails

made of tightly, hard, keratinized epidermal cells

nail body

portion of the nail that is visible

lunula

means little moon, crescent shaped at the base of the nail

hyponychium

The slightly thickened layer of skin that lies beneath the free edge of the nail plate.

eponychium

narrow band of epidermis above the lunula

matrix

growth of nails is in the _________

skin lesions

any measurable variation from normal structure of the skin

skin imbalances

disorders from allergies

elevated lesions

cast a shadow outside the edges as warts, plaque, blister

flat lesions

do not cast a shadow

depressed lesions

cast a shadow within their edges as lacerations, ulcer, fissures

viral

infections, cold sores, herpes simplex especially around lips and oral mucosa

warts

infection withbenign neoplasms caused a papillomavirus

fungal

infection such as athletes foot

bacterial

infection with boils and carbuncles inflammation of hair follicle and sebaceous glands especially on face or dorsal side of neck, impetigo Streptococcus infection

contact dermatitis

condition in which skin becomes red, sore, or inflamed after direct contact with a substance. two kinds of ______ _____ irritant or allergies

irritant dermatitis

caused by contact with acids, alkaline earth metals such as soaps and detergents, fabric softeners, solvents, or other chemicals

allergic contact dermatitis

caused by exposure to a substance or material to which you have become extra sensitive or allergic

corticosteroid

treat allergic contact dermatitis

psoriasis

chronic noninfectious skin disease, skin becomes dry and scaly, often with pustules and many varieties, stratum corneum gets thick as dead cells accumulate

vitiligo

an autoimmune pigmentation disorder where melanocytes in the epidermis are destroyed

basal cell carcinoma

least malignant, most common, stratum basale cant form keratin, lose boundary layer between epidermis and dermis, 99% of these cancers are fully cured

squamous cell carcinoma

20% of all skin cancers, cancer of the cells in stratum spinosum, arise from squamous cells, usually induced by sun, good chance of recovery

malignant melanoma

cancer in melanocytes, 1% of skin cancers, poor chance of cure, often begins with moles, spreads rapidly