Chapter 5- Integumentary Systems

integument

skin, the largest organ in the body

integumentary system

elaborate system of distinct tissues includes glands that produce several types of secretions, nerves that transmit impulses, and blood vessels that help regulate body temperature

the skin covers and protects all outer surfaces of the body and performs many vital functions, including the sense of touch

androgen

Generic term for an agent (usually a hormone, such as testosterone or androsterone) that stimulates development of male characteristics

ductule

Very small duct

synthesize

Forming a complex substance by the union of simpler compounds or elements

epidermis

outer layer of the skin, is relatively thin over most areas but is thickest on the palms of the hands and the soles of the feet

stratum corneum

composed of dead, flat cells that lack a blood supply and sensory receptors

Its thickness is related to normal wear of the area it covers

basal layer

the only layer of the epidermis that is composed of living cells where new cells are formed

Keratin

hard protein material, relatively waterproof

melanin

a black pigment, provides a protective barrier from the damaging effects of the sun's ultraviolet radiation, which can cause skin cancer

albino

cannot produce melanin, has a marked deficiency of pigment in the eyes, hair, and skin

dermis (corium)

second layer of skin, lies directly beneath the epidermis, composed of living tissue and contains numerous capillaries, lymphatic vessels, and nerve endings

sebaceous

oil

sudoriferous

sweat

Hypodermis (subcutaneous layer)

binds the dermis to underlying structures, composed primarily of loose connective tissue and adipose (fat) tissue interlaced with blood vessels

Adipose

fat

sudoriferous glands

produce sweat

sebaceous glands

produce oil

exocrine glands

secrete substances through ducts to an outer surface of the body rather than directly into the bloodstream

axillae

armpits

Sebum

oil secretion

hair shaft

the visible part of the hair, the part that is embedded in the dermis is the hair root

hair follicle

the root together with its coverings

papilla

the bottom of the follicle is a loop of capillaries enclosed in a covering

nail root

forms the nail and composed of keratinized, stratified, squamous epithelial cells producing a very tough covering

lunula

region where new growth occurs, whiteish appearance because the vasular dissue under does not show

adip/o

fat

lip/o

fat

steat/o

fat

cutane/o

skin

sub-

under

-ous

pertaining to

dermat/o

skin

-plasty

surgical repair

derm/o

skin

hypo-

under, below, deficient

hidr/o

sweat

sudor/o

sweat

ichthy/o

dry, scaly

aden

gland

kerat/o

horny tissue; hard; cornea

melan/o

black

myc/o

fungus

onych/o

nail

ungu/o

nail

pil/o

hair

trich/o

hair

scler/o

hardening; sclera (white of eye)

seb/o

sebum, sebaceous

-rrhea

discharge, flow

squam/o

scale

xen/o

foreign, strange

-graft

transplantation

xer/o

dry

-therapy

treatment

an-

without, not

epi-

above, upon

homo-

same

dermatology

the medical specialty concerned with diseases that directly affect the skin and systemic diseases that manifest their effects on the skin

dermatologist

physician who specializes in diagnosis and treatment of skin diseases

lesions

areas of tissue that have been pathologically altered by injury, wound, or infection

localized

over an area of a definite size

systemic

widely spread throughout the body

primary skin lesions

the initial reaction to pathologically altered tissue and may be flat or elevated

secondary skin lesions

changes that take place in the primary lesion as a result of infection, scratching, trauma, or various stages of a disease

first-degree (superficial) burns

least serious type of burn because they injure only the top layers of the skin, the epidermis. These burns are most commonly caused by brief contact with dry or moist heat (thermal burn), spending too much time in the sun (sunburn), or exposure to chemicals (chemical burn)

Erythema

skin redness

hyperesthesia

acute sensitivity to such sensory stimuli as touch, heat, or cold

second-degree (partial-thickness) burns

burns are deep burns that damage the epidermis and part of the dermis

may be caused by contact with flames, hot liquids, or chemicals

symptoms mimic those of first-degree burns, but fluid-filled blisters form, and the burn may heal with little or no scarring

bullae

fluid filled blisters

third-degree (full-thickness) burns

the epidermis and dermis are destroyed, and some of the underlying connective tissue is damaged, leaving the skin waxy and charred with insensitivity to touch

underlying bones, muscles, and tendons may also be damaged

caused by corrosive chemicals, flames, electricity, or extremely hot objects; immersion of the body in extremely hot water; or clothing that catches fire

ulcerating wounds develop, and the body attempts to heal itself by forming scar tissue

dermatoplasty

skin grafting

Neoplasms

abnormal growths of new tissue that are classified as benign or malignant

Benign Neoplasms

noncancerous growths composed of the same type of cells as the tissue in which they are growing

they harm the individual only insofar as they place pressure on or interfere with the functioning of surrounding structures

Malignant Neoplasms (cancer)

composed of cells that tend to become invasive and spread to remote regions of the body

tend to enter blood and lymph vessels and travel to remote regions of the body to form secondary tumor sites

if left untreated, cancer tends to be progressive and generally fatal

immunotherapy (biotherapy)

a newer treatment that stimulates the body's own immune defenses to fight tumor cells

Pathologists

grade and stage tumors to help in diagnosis and treatment planning, provide a possible prognosis, and aid comparison of treatment results when different treatment methods are used

Tumor Grading

cells from the tumor site are evaluated to determine how closely the biopsied tissue resembles normal tissue

the greater the difference between the normal tissue and the biopsied tissue, the more serious is the grade of cancer

Grade I tumor

tumor cells well differentiated; close resemblance to tissue of origin and, thus, retaining some specialized functions

grade II tumor

tumor cells moderately or poorly differentiated

less resemblance to tissue of origin

more variation in size and shape of tumor cells

increased mitoses

Grade III tumor

tumor cells poorly differentiated; increased abnormality in appearance with only remote resemblance to the tissue of origin, marked variation in shape and size of tumor cells, greatly increased mitoses

Grade IV tumor

Tumor cells are very poorly differentiated, abnormal appearance to the extent that recognition of the tumor's tissue origin is difficult, extreme variation in size and shape of tumor cells

tumor-node-metastasis (TNM) system

an international system that allows comparison of statistics among cancer centers

T—size and invasiveness of the primary tumor

N—area lymph nodes involved

M—invasiveness (metastasis) of the primary tumor

basal cell carcinoma

the most common type of skin cancer, is a malignancy of the basal layer of the epidermis, or hair follicles

commonly caused by overexposure to sunlight

locally invasive but rarely metastasize

squamous cell carcinoma

arises from skin that undergoes pathological hardening of epidermal cells

Carcinogens

cancer-causing agents

in situ

original site

invasive

penetrate the surrounding tissue

malignant melanoma

a malignant growth of melanocytes, highly metastatic, with a higher mortality rate, most lethal of the skin cancers

Abscess

Localized collection of pus at the site of an infection

acne

Inflammatory disease of the sebaceous glands and hair follicles of the skin with characteristic lesions that include blackheads (comedos), inflammatory papules, pustules, nodules, and cysts and are usually associated with seborrhea

Alopecia

Partial or complete loss of hair resulting from normal aging, an endocrine disorder, a drug reaction, anticancer medication, or a skin disease

Bowen disease

Very early form of skin cancer, which is easily curable and characterized by a red, scaly patch on the skin

Cellulitis

Diffuse (widespread), acute infection of the skin and subcutaneous tissue

Cholasma

Pigmentary skin discoloration usually occurring in yellowish-brown patches or spots

comedo

Typical small skin lesion of acne vulgaris caused by accumulation of keratin, bacteria, and dried sebum plugging an excretory duct of the skin

decubitus ulcer

Inflammation, sore, or skin deterioration caused by prolonged pressure from lying in one position that prevents blood flow to the tissues

Ecchymosis

Skin discoloration consisting of a large, irregularly formed hemorrhagic area with colors changing from bluish black to greenish brown or yellow

eczema

Chronic inflammatory skin condition that is characterized by erythema, papules, vesicles, pustules, scales, crusts, and scabs and accompanied by intense itching (pruritus)

Erythema

Redness of the skin caused by swelling of the capillaries