Chapter 12 Medical Terminology

and

Chapter 5 Body Structures:

THE INTEGUMENTARY SYSTEM

FUNCTIONS OF THE INTEGUMENTARY SYSTEM – THE

OUTER COVERING OF THE BODY – THE SKIN

Waterproofs body and prevents water loss Intact skin plays important role in immune

system Receptor for the sense of touch Screens out harmful UV rays from sun while

synthesizing Vitamin D

STRUCTURES OF THE INTEGUMENTARY SYSTEM

Skin (derma or cutaneous) Epidermis Dermis

Tissues within the dermis Subcutaneous Layer

ASSOCIATED STRUCTURES OF THE INTEGUMENTARY SYSTEM –

AND THEIR FUNCTIONS Sebaceous glands –

secretes sebum to lubricate skin and discourage bacteria growth

Sweat glands – Help regulate body temp and H2O content by secreting

sweat – some metabolic waste secreted Hair –

Helps control heat loss Nails –

Protects dorsal surface of distal phalanges

ASSOCIATED STRUCTURES

THE EPIDERMIS –MADE UP OF SEVERAL LAYERS OF EPITHELIAL CELLS

Outer most layer of the skin – epidermis Does not contain any blood vessels or

connective tissue Dependent on lower layers for nourishment Cells are produced in lower (basal) layer and

push upwards – when they reach the surface, they die and fill with keratin Keratin: water-repellent protein

Soft keratin: primary component of epidermis Hard keratin: found in hair and nails

THE EPIDERMIS

www.aatb.org/aatbskinbank/ mission_statement.htm

coolshade.tamu.edu/ skin_2.html

Cells and Layers of the Epidermis

Squamous (scalelike) epithelial tissue – upper layer, consists of flat, scaly cells that are

continuously sloughed off Basal layer – Also contains melanocytes

Melanocytes: cells that produce and contain dark brown-black pigment (melanin) –

Type and amount of melanin determines color of skin

Melanin also protects skin against harmful UV rays of the sun

THE DERMIS – THICK LAYER OF LIVING TISSUE DIRECTLY BELOW EPIDERMIS

Contains: Connective tissue Blood and lymph vessels Nerve fibers: endings receive impulses enabling

body to recognize sensory stimuli like touch, temp, pain, and pressure

Hair follicles Sebaceous and Sweat glands

TACTILE: pertaining to touch

PERCEPTION: the ability to recognize

sensory stimulus

www.bmb.psu.edu/.../tissues/ tissnote.htm

TISSUES WITHIN THE DERMIS –Collagen: means glue, contains tough but flexible protein material

Also found in bone, cartilage, tendons, and ligamentsMast Cells: respond to injury or infection by producing heparin and histamine

Heparin: released in response to injury, is an anticoagulant Histamine: released in response to allergens, causes itching and increased mucous secretion

THE SUBCUTANEOUS LAYER – CELLULITE = NONTECHNICAL TERM FOR SUBCUE FATTY DEPOSIT

Just below dermis Connects skin to

surface muscles Made up of loose

connective tissue and adipose (fatty) tissue

Lipocytes: fat cells, predominant in the subcutaneous layer where they manufacture and store large quantities of fat

THE SEBACEOUS GLANDS – CLOSELY ASSOCIATED WITH HAIR FOLLICLES, LOCATED IN DERMIS

Secrete sebum which is released through ducts opening into the hair follicles

Sebum lubricates skin and discourages the growth of bacteria on the skin = slightly acidic

What glands are considered part of the Integumentary system as modified sebaceous glands but are also part of the Reproductive system??

MAMMARY GLANDS

THE SWEAT GLANDS – TINY GLANDS FOUND ON ALMOST ALL BODY SURFACES

Most numerous in palms of hands and soles of the feet, forehead, and armpits (axilla)

Pores: openings on the surface of the skin through which sweat gland ducts open

Sweat: perspiration – secreted by sweat glands Made up of 99% water + salt + metabolic waste Perspiration: excretion of excess H2O – cools

body as sweat evaporates into air What causes body odor associated with sweat? INTERACTION SWEAT + BACTERIA ON SKIN

THE HAIR – FIBERS OF TIGHTLY FUSED, DEAD

PROTEIN CELLS FILLED WITH HARD KERATIN

What factors determine hair color?? Amount of melanin produced by the

melanocytes that surround core of the hair shaft

Hair follicles: sacs that hold root of hair fibers Arrector pili: (erector muscles) tiny muscle

fibers attached to hair follicles that, upon contraction, cause the hair to stand up (i.e. cold or fright = goose bumps) reducing heat loss through skin

THE NAILS – UNGUIS, KERATIN PLATE COVERING

DORSAL SURFACE OF DISTAL PHALANGES

Each nail consists of the following: Nail body – translucent, made up

of hard keratinized plates of epidermal cells

Nail bed – joins nail body to underlying connective tissue, nourishes the nail

Blood vessels give nail bed it’s pink color

Free edge – the portion not attached to the nail bed, extends beyond the tip of the phalanx

MEDICAL SPECIALTIES

Dermatologist Diagnosing and treating disorders of the skin

Cosmetic surgeon – Plastic Surgeon Restoration and repair

PATHOLOGY OF THE INTEGUMENTARY SYSTEM

Acne vulgaris: inflammatory disease with pustular eruptions of the skin in or near the sebaceous glands

Comedo: aka blackhead - sebum plug exposed to air = oxidizes

Seborrheic Dermatitis: aka dandruff – scaling of the scalp due to inflammation of upper layers of the skin

Acne vulgaris Comedo orblackheads

Seborrheicdermatitis

Sebaceous cyst

anhidrosis

SWEAT GLAND DISORDERS

Anhidrosis: lacking sweat Hyperhidrosis: excessive sweat Diaphoresis: profuse, but not necessarily

excessive sweating Miliaria: heat rash/prickly heat – inflammation

caused by trapped sweat

HAIR”Y “DISORDERS

Excessive Hairiness Hirsutism: appearance of male body or facial

hair patterns in the female Abnormal hair loss

Alopecia: baldness, partial or complete Female pattern baldness: thinning in front and

on sides, sometimes on crown Male pattern baldness: receding hairline from

front to the back until only a horseshoe shaped area remains in back and temples

hirsutism

folliculitis

alopecia

PIGMENTATION

Albinism: deficiency or absence of pigment in skin, hair, eyes due to abnormality in production of melanin

Chloasma: mask of pregnancy – brownish colored spots on face

chloasma

melanosis

SURFACE LESIONS – PATHOLOGIC CHANGE OF TISSUES DUE TO DISEASE OR INJURY

Described by appearance, location, color, and size (cm)

Contusion: does not break skin, swelling, discoloration, and pain

Ecchymosis: bruise – purple discoloration caused by hemorrhaging within the skin

Nodule: solid bump, may be felt within skin or may be raised as if it had formed below the surface and pushed upward (i.e. cyst)

Papule: solid raised skin lesion < 0.5 cm in diameter (i.e. warts, insect bites, and skin tags)

SURFACE LESIONS OF THE SKIN

FLUID-FILLED LESIONS

LESIONS THROUGH THE SKIN

WARNING!!

THE FOLLOWING PICTURES MAY BE DIFFICULT FOR VIEWING

VIEW AT YOUR DESCRETION

bruise

ecchymosis

purpura

petechia

contusion

Birthmarkvascular

Port-wine stain

dermatitis

Open lesions

coccidioidomycosis

Nodular skin lesions

Ulcers

Skin ulcer post spider bite