BIO 210 ch. 5 Integumentary System

Cuticle

Stratum corneum from the nail fold that extends onto the nail body

Lanugo

Delicate, unpigmented hair that develops and covers the fetus by the fifth or sixth month

Cyanosis

A bluish skin color caused by a decrease in blood oxygen content

Corn

A cone-shaped structure that forms over bony prominences

Third-degree Burn

A full-thickness burn in which the epidermis and dermis are completely destroyed and deeper tissue may be involved

Dermis

A layer of connective tissue beneath the epidermis

Papillary Layer

A layer of the dermis that is areolar connective tissue with thin fibers that are somewhat loosely arranged.

Matrix

A mass of epithelial cells inside the hair bulb which produces the hair

ABCDE Rule

A method of detecting melanoma: Asymmetry (one side of the lesion doesn't match the other side) Border irregularity (edges are ragged, notched, or blurred) Color (pigmentation not uniform) Diameter (greater than 6m) Evolving (lesion changes over time)

First-degree Burn

A partial-thickness burn involving only the epidermis

Second-degree Burn

A partial-thickness burn that damages the epidermis and dermis

Albinism

A recessive genetic trait that causes a deficiency or an absence of melanin

Cuticle

A single layer of cells, with hard keratin, that forms the hair surface

Psoriasis

A skin condition characterized by increased cell division in the stratum corneum that sloughs to produce large, silvery scales

Lunula

A small part of the nail matrix that can be seen through the nail body as a whitish, crescent-shaped area at the base of the nail

Actinic Keratosis

A small, scaly, crusty bump that arises on the surface of the skin which, if untreated, progresses to squamous cell carcinoma 2%-5% of the time

Callus

A thickened area of the skin that occurs when the number of layers of the stratum corneum greatly increases due to friction or pressure

Nail

A thin plate, consisting of layers of dead stratum corneum cells with hard keratin, located on the distal ends of the digits of humans and other primates

Stratum Lucidum

A thin, clear zone above the stratum granulosum, consisting of several layers of dead cells with indistinct boundaries

Moderate Burn

A third-degree burn of 2%-10% of the BSA or second-degree burn of 15%-25% of the BSA.

Minor Burn

A third-degree burn of less than 2% or a second-degree burn of less than 15% of the BSA

Major Burn

A third-degree burn over 10% or more of the BSA A second-degree burn over 25% or more of the BSA A second- or third-degree burn of the hands, feet, face, genitals, or anal region

Hair Follicle

A tubelike invagination of the epidermis into the dermis from which the hair develops

Carotene

A yellow pigment found in plants, such as carrots and corn. Humans ingest it and use it as a source of Vitamin A.

Jaundice

A yellowish skin color that can occur when the liver is damaged by a disease such as viral hepatitis

Acne

An inflammation of the hair follicles and sebaceous glands

Intramuscular Injection

An injection into a muscle deep to the subcutaneous tissue, accomplished by inserting a needle at a 90-degree angle to the skin

Intradermal Injection

An injection into the dermis, such as for the tuberculin skin test

Subcutaneous Injection

An injection into the fatty tissue of the subcutaneous tissue, such as for an insulin injection

Sebum

An oily, white, lipid-rich substance produced by sebaceous glands. It lubricates the hair and the surface of the skin, which prevents drying and protects against some bacteria.

Langerhans Cells

Cells that are part of the immune system

Keratinocytes

Cells that produce keratin, which makes them hard. They are responsible for the ability of the epidermis to resist abrasion and reduce water loss

Dermis

Connective tissue with fibroblasts, a few adipose cells, and macrophages

Cornified Cells

Dead cells with a hard protein envelope filled with the protein keratin

Moles

Elevations of the skin that are variable in size and are often pigmented and hairy. They are aggregations ("nests") of melanocytes in the epidermis or dermis.

Nail Bed

Epithelial tissue under the nail

Accessory Skin Structures

Hair, smooth muscles called the arrestor pili, glands, and nails

Erythma

Increased redness of the skin resulting from increased blood flow through the skin

Burn

Injury to tissue caused by heat, cold, friction, chemicals, electricity or radiation

Melanocytes

Irregularly-shaped cells with many long processes that extend between the keratinocytes of the stratum basale and the stratum spinosum. These cells contribute to skin color.

Striae (stretch marks)

Lines of scar tissue that may develop if dermis ruptures when skin is overstretched, leaving lines that are visible through the epidermis

Lamellar Bodies

Lipid-filled, membrane-bound organelles found in the stratum spinosum

Terminal Hairs

Long, coarse, pigmented hairs that replace the lanugo of the scalp, eyelids, and eyebrows near the time of birth

Mammary Glands

Modified apocrine sweat glands located in the breasts

Ceruminous Glands

Modified eccrine sweat glands that produce cerumen (earwax)

Epithelial Root Sheath

Part of the hair follicle with an external and internal part. At the opening of the follicle, it has all the strata found in thin skin, but deeper in the follicle, the number of cells decrease until at the hair bulb only the stratum basale is present

Hair Papilla

Projection of the dermis into the hair bulb which contains blood vessels that provide nourishment to the cells of the matrix

Dermal Papillae

Projections underlying thick skin in parallel, curving ridges that shape the overlying epidermis into ridges

Vellus Hairs

Short, fine, usually unpigmented hairs that replace the lanugo everywhere except the scalp, eyelids, and eyebrows near the time of birth

Sebaceous Glands

Simple or compound alveolar glands located in the dermis, usually connected by a duct to the superficial part of the hair follicle

Eccrine Sweat Glands

Simple, coiled tubular glands located in almost every part of the skin, most numerous in the palms and the soles.

Apocrine Sweat Glands

Simple, coiled tubular glands that produce a thick secretion rich in organic substances. They open into hair follicles, but only in the axillae and genitalia.

Thick Skin

Skin found in areas subject to friction. It has all five epithelial strata, and the stratum corneum has many layers of cells.

Thin Skin

Skin that is more flexible than thick skin. Each stratum contains fewer layers of cells than are found in thick skin; the stratum granulosum frequently consists of only one or two layers of cells, and the stratum lucid generally is absent.

Desquamate

Slough off, as older cells which are pushed to the surface by the formation of new cells

Freckles

Small, discrete areas of the epidermis with a uniform brown color. They are the result of an increased amount of melanin in the stratum basale keratinocytes.

Arrector Pili

Smooth muscle cells associated with each hair follicle

Merkel Cells

Specialized epidermal cells associated with the nerve endings responsible for detecting light touch and superficial pressure

Hair Bulb

The base of the root of the hair

Cortex

The bulk of the hair--consists of cells containing hard keratin

Medulla

The central axis of the hair, consisting of two or three layers of cells containing soft keratin

Stratum Basale

The deepest layer of the epidermis, consisting of a single layer of cuboidal or columnar cells

Melanin

The group of pigments responsible for skin, hair and eye color

Stratum Spinosum

The layer superficial to the stratum basal, consisting of 8-10 layers of many-sided cells

Melanoma

The least common, but most deadly, type of skin cancer, which arises from melanocytes

Reticular Layer

The main layer of the dermis. It is composed of dense irregular connective tissue.

Basal Cell Carcinoma

The most common type of skin cancer which arises from cells in the stratum basale

Stratum Corneum

The most superficial layer of the epidermis, consisting of 25 or more layers of dead squamous cells joined by desmosomes

Epidermis

The most superficial layer of the skin--it consists of epithelial tissue

Root of the hair

The part of the hair below the surface of the skin

Shaft of the hair

The part of the hair that protrudes above the surface of the skin

Nail Root

The part of the nail covered by skin and extending distally from the nail matrix

Dermal Root Sheath

The portion of the dermis that surrounds the epithelial root sheath

Keratinization

The process of cells moving from the deeper epidermal layers to the surface, changing shape and chemical composition--they become filled with keratin

Excretion

The removal of waste products from the body

Age spots

The result of an increase in the number of melanocytes

Cleavage (or tension) Lines

The result of elastic and collagen fibers being oriented more in some directions than in others

Squamous Cell Carcinoma

The second-most common type of skin cancer that arises from cells in the stratum spinosum and can s\appear as a wartlike growth; a persistent, scaly, red patch; an open sore; or an elevated growth with a central depression

Growth Stage

The stage of hair production when stem cells in the matrix cells give rise to transit amplifying cells that differentiate, become keratinized and die

Resting Stage

The stage of hair production when there is no hair growth and the hair is held in the hair follicle

Strata

The stages of keratinization (plural of stratum)

Stratum Granulosum

The stratum that consists of two to five layers of diamond-shaped cells. Its name comes from the nonmembrane-bound protein granules of keratohyalin, which accumulate in the cytoplasm of the cell.

Integumentary System

The system that consists of the skin and accessory structures, such as hair, glands, and nails

Nail Body

The visible part of the nail

Subcutaneous Tissue (Hypodermis)

Tissue that attaches the skin to underlying bone and muscle and supplies it with blood vessels and nerves.

Warts

Uncontrolled growths of the epidermis caused by the human Papillomavirus

Melanosomes

Vesicles produced by the Golgi apparatus of the melanocyte