Lab Exam: The Integumentary System

Stratum granulosum

(granular layer) a thin layer named for the abundant granules its cells contain. Upper boarder, cells begin to die.

Stratum lucidum

2nd layer of skin; clear layer; translucent cells in thick skin containing keratin fibrils

Skin Color

A result of the relative amount of melanin in the skin, the relative amount of carotene in the skin and the degree of oxygenation of the blood. • The more melanin produced, the darker the skin. • Skin color can help be a diagnostic tool.

Sebaceous glands

Accumulatoin of oily material that is known as a blackhead

Eccrine glands

Also called merocrine sweat glands, are distributed all over the body. Produce clear perspiration primarily of water, salts, and urea. Under control of the nervous system

Stratum spinosum

Area where weblike pre-keratin filaments first appear

Papillary Layer

Dermal layer responsible for finger prints

Sweat (Sudoriferous Glands)

EXOCRINE Glands; Widely distributed all over the skin. Outlets are called pores

Dermography: Fingerprinting

Each of us is unique with a different set of fingerprints. Friction ridges responsible for fingerprint appear in several patterns. 3 most common patters are: aches, loops, and whorls.

Free nerve endings, meisners corpucles, and pacinian corpuscles:

Free nerve endings, meisners corpucles, and pacinian corpuscles:

Keratin

a cell of epidermis; A fibrous protein that gives the epidermis its durability and protective capabilities. Connected by desmosomes

Keratinocytes

a cell of epidermis; literally mean KERATIN cells, they are the most abundant epidermal cells. Function to produce keratin fibrils.

Hair bulb

a collection of well-nourished germinal epithelial cells at the basal end of the follicle.

Freckle

a concentration of melanin in one spot.

Stratum spinosum (spiny layer)

a stratum consisting of several cell layers immediately superficial to the basal layer. Made up of pre-keratin protein. Appears spiky. Cells will divide rapidly but less so than SB. Only other layer besides DB to receive nourishment.

Follicle

a structure formed from both epidermal and dermal cells. Essentially dermal tissue

Epidermal dendritic cells

also called langerhans cells, these cells play a role in IMMUNITY.

Acne

an active infection of the sebaceous glands

Lunule

appears as a white crescent. Thickened nail matrix.

Blackheads

are accumulations of dried sebum, bacteria and melanin from epithelial cells in the oil duct.

Cynasosis

blue cast to the skin which would mean inadequate oxygen.

Nail bed

extension of the stratum basile beneath the nail

Sebaceous glands

found everywhere on the body except for hands and soles of feet

stratum lucidum (clear layer)

found on palms of hands and soles of the feet. Very translucent. Dead keratinocytes. Not present in regions of thin skin.

Tactile (merkel) cells

in conjuction with sensory nerve endings, form sensitive touch receptors.

Four Protective Functions of the Skin

insulation, thermal damage, protects body from chemical damage, bacterial invasion

Apocrine

less numerous type of perspiration-producing gland. Mainly found in pubic and axillary regions

Bedsore (decubitus ulcer)

localized area of tissue necrosis and death

Freckle

localized centration of melanin

Stratum basale

location of melanocytes and tactile (Merkel) cells

Epidermis

major skin area that produces derivatives (nails and hair)

Stratum spinosum

mitotic cells filled with intermediate filaments

Stratum Corneum

most superficial layer. 20-30 layers of dead cells represented only by flat membranous sacs filled with keratin. Accounts for bulk of epidermal thickness. DEAD skin cells. Scalelike remnants are fully keratinized. Constantly rubbing off and being replaced by division of the deeper cells.

Stratum corneum (horny layer)

most superficial layer. 20-30 layers of dead cells represented only by flat membranous sacs filled with keratin. Accounts for bulk of epidermal thickness. DEAD skin cells. Scalelike remnants are fully keratinized. Constantly rubbing off and being replaced by division of the deeper cells.

Sebaceous (oil glands):

nearly found all over the skin except for palms of the hands and soles of the feet.

Sweat gland-apocrine

perspiration glands with a role in temperature control

Melanin and Carotene

pigments that contribute to skin color

Hair/nails

primarily dead/keratinized cells

Sebum

product of sebaceous glands. Mixture of oil substances and fragmented cells that acts as a lubricant to keep the skin soft and moist (a natural skin cream). Keeps hair from becoming brittle.

Papillary layer

region of areolar connective tissue

sebaceous glands

secrets a lubricant for hair and skin

Hair follicle

sheath formed of both epithelial and connective tissues

Cutaneous receptors

specialized nerve endings that respond to temp, touch, etc.

Vitamin D

substance manufactured in the skin that plays a role in calcium absorption

Reticular layer

the deepest skin layer. Composed of dense irregular connective tissues and contains many arteries and veins, sweat and sebaceous glands, and pressure receptors.

Papillary layer

the more superficial dermal region composed of areolar connective tissue. Very uneven.

Nails

• "Hornlike" • Body: the visible attached portion • Free edge: the portion of the nail that grows away from the body.

Accessory Organs of the Skin

• Include cutaneous glands, hair, and nails. All derivatives of the epidermis, but reside in the dermis. • Originate in the stratum basale and grow downward into deeper skin regions.

Hair

Structure consisting of a medulla, a central region of surrounded first by the cortex and then by a protective cuticle. ABRASION of the cuticle results in split ends.

Stratum basale

Base layer; epidermal region exhibiting the most rapid cell division

Dermis

Both layers are heavily filled with collagenic and elastic fibers. Gives skin its youth, and loses fat cells which leads to wrinkling and inelasticity. Plays a role in body temp. Richly supplied with nerve supply and highly receptor organs. Transmits messages to the central nervous system for interpretation.

Stratum corneium and Lucidum

Dead cells

Stratum basale (basal layer)

Deepest epidermal layer; one row of actively mitotic stem cells: some newly formed cells become part of the more superficial layers. Constantly undergoing mitotic cell division to produce millions of new cells daily.

Cutaenous Glands

Fall into TWO categories: the sebaceous glands and the sweat glands.

Dermal papillae

Fingerlike projections from its superior surface. Responsible for fingerprints which are unique patterns of epidermal ridges. Pain and nerve receptors are also found here.

Apocrine glands

Found predominantly in the axillary and genital areas. Secrete a milky protein and fat rich substance

Dermis

Has abundant elastic and collagenic fibers

The Skin

It protects the body from things such as thermal damage, bacteria invasion, chemical damage, mechanical damage (like bumps and cuts)

Epidermis

Its structure is a keratinized stratified squamous epithelium

The Skin

Job also includes sweat and metabolic duties.

Dermis

Vascular region

Root

Portion enclosed within the follicle.

Shaft

Portion projecting from the scalp surface

Stratum corneum

Scalelike dead cells, full of keratin, that constantly slough off

Nail folds

Skin folds that overlap the borders of the nail.

Arrector pili muscles

Small bands of smooth muscle cells connect each hair follicle to the papillary layer of the dermis. Responsible for goosebumps!

Melanocytes

Spidery black cells that produce brown to black pigment called melanin. The skin tans because melanin production increases when the skin is exposed to sunlight.

Keratin

the tough water-repellent protein found in the epidermal cells

Eponychium

thick proximal nail fold commonly called the "cuticle"

Nail matrix

thickened proximal part of the nail bed containing germinal cells responsible for nail growth.