HAN 312: Integumentary System

Integumentary System

skin + accessory organs (hair, nails, sebaceous and sweat glands)

Functions of the skin

• protect against pathogens +dehydration

• communicate sensory information

• temperature regulation

• produce secretions

Epidermis

outer layer

dermis

deep layer

• contains accessory organs of the skin

• collagen fibers

hypodermis/subcutaneous tissue

• connects skin to surface muscles

• lipocytes manufacture + store fat

Hair

• fiber composed of keratin

• melanocytes

  • eumelanin

  • pheomelanin

Eumelanin

brown/black pigment

Pheomelanin

red/yellow pigment

Nails

• keratin plates cover dorsal surface

• extend indefinitely unless cut or broken

• toenails grow slower

Paronychium

soft tissue surrounding nail border

Paronychia

• inflammation and infection around a nail due to bacteria or fungi

• causes— nail biting, aggressive manicuring

Sebaceous glands

• dermal layer

• secrete oily sebum

  • lubricates + minimizes water loss

• associates with hair follicles

• influenced by sex hormones

Eccrine Sweat Glands

• most common

• most numerous in palms of hand and soles in feet

Sweat

• colorless and odorless

• cools the body as it evaporates

apocrine sweat glands

• active from puberty on

• concentrated near reproductive organs and and armpits

Icterus

yellowing of the sclera

caus/o

burn, burning

cutane/o

skin

disaphor/o

profuse sweating

hidr/o

sweat

ichthy/o

scaly, dry

kerat/o

hard

myc/o

fungus

onych/o

nail

pil/o

hair, hair follicle

rhytid/o

wrinkle

seb/o

sebum

squam/o

scale-like

trich/o

hair

ungu/o

nail

xer/o

dry

pustule

pus filled

wheal

smooth, slightly elevated, edema

cyst

fluid or semisolid thick walled filled sac

vesicle

clear fluid, blister

crust (scab)

dried serum and cellular debris

polyp

benign growth extending from mucous membrane surface

Macule

discolored, flat

Erosion

wearing away, loss of epidermis

Nodule

solid, elevated mass, more than 1 cm

fissure

slit, groove

ulcer

open sore on skin or mucous membrane

Papule

small, solid elevation, pimple or plaque

Cyst

• cutaneous lesion

• closed sac that contains liquid or semiliquid substances

Papule

• cutaneous lesion

• a small, raised, solid circumscribed area of the skin (pimple)

Pustule

• cutaneous lesion

• small circumscribed elevation of the skin containing pus

ulcer

• cutaneous lesion

• open sore on skin or mucous membranes within the body

Vesicle

• cutaneous lesion

• clear, fluid filled raised lesion

Ecchymosis (ecchymoses)

• bluish-purple mark (bruise) on the skin

• caused by hemorrhages into the skin

Petechia (petechiae)

small pinpoint hemorrhage

Pruritis

• itching

• symptom of dermatitis

• caused by stimulation of nerves in the skin of substances released in allergic reactions or irritation

Urticaria (hives)

• red, round wheals on the skin

• acute allergic reaction (food allergies)

Acne

eruption of the skin with increased production of sebum

Blackhead (comedo)

sebum plug partially blocking the pore

Whitehead

• pure is completely blocked

• bacteria in the skin break down the sebum, producing inflammation in surrounding tissue

Superficial (1st degree) Burn

involves only the epidermis

Partial (2nd degree) burn

thickness burn involving epidermis and dermis

full thickness (3rd degree) burn

involves destruction of entire skin

Eczema

inflammatory skin condition with erythematous, papulovesicular lesions

Psoriasis

• chronic recurrent dermatosis

• silvery gray scales

• Increased rate of growth of basal layer of epidermis

• autoinflammatory disease

Systemic Lupus Erythematosus (SLE)

• autoimmune disease of collagen in skin, joints and internal organs

• butterfly pattern

• primarily females are affected

Scleroderma

• autoimmune — chronic, progressive disease that affects the body by hardening connective tissue

• CT is widespread and made of collagen — extra can prevent proper functioning

• “hard skin”

Tinea

Infection caused by a fungus — can affect hair, skin, and nails— highly contagious

• causes Pruritus — itching

Tinea corporis

ringworm

tinea pedis

athletes foot

tinea capitis

scalp

tinea unguium

affects the nails

Vitiligo

loss of pigment in areas of the skin

• form of leukoderma

• association with autoimmune conditions

• epidermal melanocytes are lost through an autoimmune process

Herpes Simplex

• eruption of blisters on the skin and submucous membranes

• local infection of herpes virus

Herpes Zoster

• viral infection that affects the peripheral nerves

• causes eruption of blisters that follows the course of the affected nerves

• shingles

Impetigo

• highly contagious bacterial skin infection

• most common in children

• caused by Staphylococcus aureus, or Strepotoccous Pyogenus bacteria

• first sign— red itchy skin

abscess

circumscribed collection of pus caused by a bacterial infection

carbuncle

collection of large localized abscesses seated in groups of hair follicles and connected by channels

furuncle

infection of hair follicle

cellulitis

inflammation of the subcutaneous layer of the skin

Keloid (skin neoplasm)

• thickened scar that develops after trauma or surgical incision

• result of excessive collagen formation during CT tissue repair

Leukoplakia (skin neoplasm)

• white, thickened patches on mucous membrane tissue of tongue or cheek

• one type is a precancerous lesion common in smokers

Nevus (skin neoplasms)

pigmented lesion of skin (moles)

Dysplastic Nevi

atypical cells —may progress to melanoma

Basal Cell Carcinoma

• malignant tumor of the basal cell layer of epidermis

• most common

• slow growing

• occurs on exposed area of skins that are chronically exposed to sun

Squamous Cell carcinoma

• malignant tumor of the cell squamous epithelial cells in the epidermis

• tumor can be found wherever squamous epithelium is found (mouth, larynx, bladder, esophagus, lungs)

Actinic Keratoses

• SCC if not removed

• premalignant lesions in people with sun damaged skin

Malignant Melanoma

• cancerous growth composed of melanocytes

• combo of genetic predispo + exposure to ultraviolet light

• can mestasize to lung, liver, bone, brain

Skin Biopsy

skin lesions are removed for a microscopic exam

frozen section

thin slice of tissue cut from a frozen specimen used for rapid microscopic diagnosis

Skin test

used to diagnose allergies

Mohs micrographic surgery

• thin layers of malignant cells are removed and examined microscopically

• used to treat basal cell and squamous cell carcinomas as well as other tumors