Milady Chp 10 Physiology & Hisology of the Skin

apocrine glands

Coiled structures attached to hair follicles found in the underarm and genital areas.

arrector pili muscle

small, involuntary muscles in the base of the hair follicle that cause goose flesh when the appendage contracts.

barrier function

The protective barrier of the epidermis; the corneum and intercelluar cement protect the surface from irritation and dehydration.

ceramides

glycolipid materials that are a natural part of the skins intercellular matrix and barrier function

collagen

fiburous, connective tissues made from protein; that lies on the top of the dermis; gives skin its firmness. Topically, a large, long-chain molecular protein that lies on the top of the skin and binds water; derived from the placentasof cows or other sources.

corneocytes

another name for a stratum corneum cell. Hardened, waterproof,
protective keratinocytes; these "dead" protein cells are dried out and lack nuclei.

dermal papillae

Membranes of ridges and grooves that attach to the epidermis; contains nerve endings and supplies nourishment through cappilaries to skin and follicles.

dermis

aka derma, corium, cutis, or true skin; support layer of connective tissue, collagen, and elastin and intercellular fluids are the main compononets. Fibroblasts and immune cells are found here.

desmosomes

the structures that assist in holding cells together; intercellular connections made of proteins.

eccrine glands

Sweat glands found all over the body with opening on the skins surface through pores; not attached to hair follicles, do not produce an offensive odor.

elastin

portein fiber found in the dermis; gives skin its elasticity and firmness.

epidermal growth factor (EGF)

stimulates cells to reproduce and heal

epidermis

outermost layer of skin; a thin, protective layer with many cells, mechanisms, and nerve endings. Include keratinocytes, immune cells and intercellular fluids/ It is made up of five layers: stratum corneum, lucidum, granulosum, spinosum and germinativum

eumelanin

a type of melanin that is dark brown to black in color

fibroblasts

cells that stimulate cells, collagen, and amino acids that form proteins.

follicles

hair follicles and sebaceous follicles are tubelike openings in the epidermis

glycation

caused by an elevation in blood sugar, the binding of a protein molecule to a glucose molecule resulting in the formation of damaged, nonfunctioning structures, known as Advanced Glycation End products (aka AGES). Glycation alters protein structures and decreases biological activity.

hair papillae

Cone-shaped elevations at the base of the follicles that fit into the bulb. The papillae are filled with tissue that contains the blood vessels and cells necessary for hair growth and follicle nourishment.

hyaluronic acid

hydrating fluids found in the skin; hydrophilic agent with water-binding properties.

hydrolipidic

hydrolipidic film is an oil water balance that protects the skins surface

intercellular matrix

Lipid substances between corneum cells that protect the cells from water loss and irritation.

keratin

fiberous protein of cells that is also the principle component of skin, hair, nails; provides resiliancy and protection

keratinocytes

epidermal cells composed of keratin, lipids and other proteins.

langerhans immune cells

Guard cells of the immune system that sense unrecognized foreign invaders such as bacteria and then processes antigens for removal through the lymph system

leukocyctes

white blood cells that have enzymes to digest and kill bacteria and parasites. These white blood cells also respond to allergies

lymph vessels

located in the dermis, these supply nourishment within the skin and remove waste.

melanin

Tiny grains of pigmnent (coloring matter) that are produced by melanocytes and deposited into cells in the stratum germanativum layer of the epidermis and in the papillary layers of the dermis. It is a protein that determines hair, eye, and skin color; a defense mechanism to protect skin from the sun.

melanocytes

cells that produce skin pigment granules in the basal layer

melanosomes

pigment carrying granules that produce melanin, a complex protein.

papillary layer

top layer of the dermis, where touch receptors, blood vessels, capillaries, and dermal papilla are found

pheomelanin

A type of melanin that is red to yellow in color

pores

tube like opening for sweat glands on the epidermis

reticular layer

deeper layer of the dermis that supplies the skin with oxygen and nutrients; contains fat cells, blood vessels, sudoriferous (sweat) glands, hair follicles, lymph vessels, arrector pili muscles, sebaceous (oil) glands, and nerve endings

rosacea

Chronic condition appearing primarily on the cheeks and nose, characterized by flushing (redness), telangiectasis (distended or dilation of the blood vessels), and in some cases the formation of papules and pustules.

sebaceous glands (oil)

protect the surface of the skin. appendages connected to folicles.

sebum

provides protection for the epidermis from external factors and lubricates both the skin and hair.

stratum corneum (horny layer)

outermost layer of the epidermis; composed of hardend corneocytes, melanin, barrier layer, acid mantle, desquemination.

stratum germinativum (basal cell layer)

active layer of the epidermis above the papillary layer of the drermis; cell mitosis, stem cells, merkel cells. responsible for growth. keratinocytes, melanocytes and lipids are all produced here

stratum granulosum (granular layer)

Production of keratin granuals in cells; additional lipid production and excretion; desmosomes dissolved by enzymes. replace cells shed from the stratum corneum.

stratum lucidum (clear)

clear cells,transparent layer of the epidermis under the stratum corneum; thickest on the palms of the hands and soles of feet

stratum spinosum (spiny layer)

large layer of epidermis above the stratum germinativum layer creating desmosomes, cell activity, desmosomes, langerhans immune cells, melanosome pigment distribution.

subcutaneous layer (hypodermis)

subcutaneous adipose (fat) tissue located beneath the dermis; a protective cushion and energy storage for the body

subcutis tissue (adipose tissue)

fatty tissue found below the dermis that gives smoothness and contour to the body, contains fat for use as energy, and also acts as a protective cushoin for the outer skin

sudoriferous glands (sweat)

excrete perspiration, regulate body temp, and detoxify the body by excreteing excess salt and unwanted chemicals

t-cells

identify molecules that have foreign peptides and also help regulate immune response

telangiectasia

capillaries that have been damaged and are now larger, or distended, blood vessles; commonly called couperose skin.

transepidermal water loss (TEWL)

water loss caused by evaporation on the skins surface

tyronaise

the enzyme that stimulates melanocytes and thus produces melanin.

uva radiation (aging rays)

longer wavelengths ranging between 320-400 nanometer that penatrate deeper into the skin; cause genetic damage and cell death. contributes up to 95% of suns uv radiation

uvb radiation (burning rays)

wavelengths range between 290-320 nanometers. have shorter, burning wavelengths that are stronger and more damaging. causes burning of the skin as well as tanning, skin aging and cancer.

protein

basic material and building blocks for body tissue

slightly acidic

a charactaristic of healthy skin

thermoregulation

evaporation, perspiration, radiation, and insulation

28 days

average adult cell turn over rate

sunlight

stimulates melanin production

90%

percentage of hair that is comprised of hard keratin

lymph

removes waste products, bacteria and excess water

nicotein in tobacco

causes contraction and weakening of the blood vessels and small capillaries that supply blood to the tissues, causing decreased circulation

phytoestrogens

come from plants

apocrine and eccrine

two types of suderiferous glands

sub q

layer bottom of hair follicle lies

spinosum

sub layer of skin langerhauns are found

reticular

sub layer of dermis where collegen and elastin originate

fibroblasts

stimulated by mitochondria

GAGs

large protein molecules and water-binding substances found between the fibes of the dermis. polysachride proteins and sugar complexes that provide hydration. ex; intersticial fluid, and hyaluronic acid

collegen, elastin, GAGs and protein

components picked up as fat rises through skin to give the body shape and contour

germanativum

sub layer where cells undergo rapid fire mitosis

sebacious glands

major contributor to TEWL

appocrine

sub gland that excretes smelly sweat

actinic

means sun

androgens

male hormone that stimulates sebaceous glands

eccrine

sub layer sweat gland found all over the body

LED therapy

stimulates mitochrondria to help heal wounds

lamellar bodies

intercellular cement

afferent nerve

nerve fibers send messages to the central nervous system and brain to react to heat, cold, pain, pressure and touch.

efferant nerve

"motor" nerve fibers convey impulses from the brain or spinal cord to the muscle glands.

collegen fibrils

embededinto junction to provide strength and adhesion

mast cells

involved in alergic reactions

extracellular matrix ECM

in the dermis is a fluid matrix called the ground substance. composed of collagen, other proteins and GAGs

desquemination

cell turn over

skin functions

protection, sensation, heat regulation, excretion, secretion, absorbtion

granulosum

production of keratin and intercellular lipids takes place here (triglicerides, ceramides, waxes, fatty acids, and other lipids are excreted from cells to create a water proof barrier

50-70%

percentage of water that skin is made up of

stem cells

mother cells that divide in the basal layer forming new daughter cells

squamous

flat and scaly

terminal differentiation

process when daughter cells that are not able to divide anymore are now programmed to end up as one specific type of cell

the dermis

primarily comprised of connective tissues made of collagen protein and elastin fibers. Also supplies the skin with oxygen and nutrients

70%

percentage of collegen that makes up the dermis

onyx

technical name for nails

6-9 months

time span organs such as the skin, heart, liver and kidneys have their cells replaced.

vitamin A and AHAs

stimulate skin cell turnover and reduce visible signs of aging

microcirculation

is the circulation of blood from the heart to arterioles (small arteries), to capillaries, to venules (small veins) and then back to the heart