FUNCTIONS OF THE SKIN

 

PROTECTIVE MEMBRANE

 

·        GUARDS DEEPER TISSUE AGAINST LOSS OF H₂O AND SALTS

 

·        GUARDS AGAINST INVASION OF PATHOGENS

 

GLANDULAR SECRETIONS - SLIGHTLY ACIDIC

 

·        SEBACEOUS - SEBUM LUBRICATES SKIN SURFACES

 

·        SWEAT - EVAPORATION AIDS BODY COOLING

 

RECEPTOR FOR SENSATIONS

 

·        ALLOWS ADJUSTMENT TO ENVIRONMENT THROUGH PAIN, TEMPERATURE, PRESSURE, TOUCH, ETC.

 

THERMOREGULATION

 

·        MESSAGES TO BRAIN (hypothalamus) REGARDING INCREASES OR DECREASES OF TEMPERATURE

 

·        BLOOD VESSELS DILATE CAUSING:

 

·        SWEAT GLANDS TO PRODUCE SWEAT

 

·        CARRIES AWAY HEAT

 

STRUCTURE OF THE EPIDERMIS

 

·        OUTERMOST, TOTALLY CELLULAR LAYER OF SKIN

 

·        COMPOSED OF SQUAMOUS (SCALE-LIKE) EPITHELIUM

 

·        ARRANGED IN STRATA (LAYERS) - STRATIFIED SQUAMOUS EPITHELIUM

 

·        HAS NO BLOOD OR LYMPH VESSELS OR CONNECTIVE TISSUE.  OXYGEN AND NUTRIENTS SEEP FROM CAPILLARIES IN DERMIS TO NOURISH DEEPER LAYERS

 

LAYERS OF EPIDERMIS

 

·        BASAL LAYER - DEEPEST, ORIGIN OF EPIDERMAL CELLS THAT ARE PUSHED UPWARD

 

·        HORNY CELLS - COMPOSED OF KERATIN

 

·        STRATUM CORNEUM - UPPER, FLATTENED CELLS

 

·        MELANOCYTES - PRODUCE MELANIN (BLACK PIGMENT); UV PROTECTION

 

·                    ALBINO - CONGENITAL ABSENCE OF MELANIN

STRUCTURE OF THE DERMIS (CORIUM)

 

·        COMPOSED OF BLOOD AND LYMPH VESSELS, NERVE FIBERS, HAIR FOLLICLES, SWEAT AND SEBACEOUS GLANDS

 

·        CONNECTIVE TISSUE 

 

·        FIBROUS COMPOSED MAINLY FROM COLLAGEN (GLUE)

 

·        SUPPORT AND PROTECT NERVE AND BLOOD NETWORKS

 

·        HAIR FOLLICLES

 

·        SEBACEOUS GLANDS - SECRETE SEBUM (OILY), LUBRICATES SKIN

 

·        SWEAT GLANDS - PRODUCE SWEAT; HELPS COOL BODY

 

STRUCTURE OF THE SUBCUTANEOUS LAYER

 

 

·        COMPOSED OF CONNECTIVE AND FATTY TISSUE

 

·                    LIPOCYTES (adipocytes)- FAT CELLS THAT MANUFACTURE AND STORE LIPIDS

 

·        PROTECTS DEEPER BODY TISSUES

 

·        ACTS AS A HEAT INSULATOR

SKIN Pathology

 

 

SYMPTOMS

 

 

·        ALOPECIA - BALDNESS DUE TO HEREDITY, DISEASE, INJURY, TREATMENT

 

·        PETECHIAE - SMALL BLACK AND BLUE MARKS (BRUISE) DUE TO HEMORRHAGES FROM INJURY OR SPONTANEOUS LEAKING OF BLOOD

 

·        PRURITUS - ITCHING ASSOCIATED WITH MANY FORMS OF DERMATITIS, ETC.

 

·        PURPURA - LARGE BRUISES DUE TO BLEEDING INTO THE SKIN

 

ABNORMAL CONDITIONS

 

 

·        BURNS - TISSUE INJURY DUE TO CONTACT WITH HEAT

 

·        FIRST-DEGREE - EPIDERMAL LESIONS, NO BLISTERS

 

·        SECOND-DEGREE - EPIDERMAL AND DERMAL LESIONS, BLISTERS

 

·        THIRD-DEGREE - MOST SERIOUS; DESTRUCTION OF EPIDERMAL AND DERMAL LAYERS AND DAMAGE TO SUBCUTANEOUS LAYER

 

 

·        GANGRENE - TISSUE NECROSIS ASSOCIATED WITH ISCHEMIA DUE TO INJURY, INFLAMMATION, FROSTBITE, DISEASE (DIABETES, ARTERIOSCLEROSIS)

 

 

·        SCLERODERMA - HARDENING OF SKIN AND SHRINKAGE OF CONNECTIVE TISSUE. AFFECTS SKIN AND OTHER ORGANS, AUTOIMMUNE; ASSOC with Polymyositis/ dermatomyositis

 

 

 

 

SKIN NEOPLASMS

 

·        BENIGN NEOPLASMS

 

·                    LEUKOPLAKIA - WHITE PATCHES ON ORAL MUCOSA, MAY BE PRE-CANCEROUS

 

·        CANCEROUS LESIONS

 

·        BASAL CELL CARCINOMA - MOST FREQUENT SKIN CANCER, USUALLY ON THE FACE, SLOW GROWING AND SELDOM METASTASIZES. AFFECTS DEEPEST LAYER OF THE EPIDERMIS

 

·        KAPOSI'S SARCOMA - ASSOCIATED WITH AIDS. GROWTH OF SMALL BLOOD VESSELS CAUSES DARK PURPLE-BLUE NODULES TO FORM. FATAL AS TUMOR METASTASIZES TO INTERNAL ORGANS.

 

·        MALIGNANT MELANOMA - CANCEROUS GROWTH OF MELANOCYTES, OFTEN ASSOCIATED WITH EXCESS EXPOSURE TO SUN.  OFTEN METASTASIZES TO LUNG, LIVER, BRAIN

 

·        SQUAMOUS CELL CARCINOMA - MALIGNANT TUMOR OF CELLS COVERING INTERNAL AND EXTERNAL SURFACES OF THE BODY

 

 

LABORATORY TESTS

 

·        BACTERIAL AND FUNGAL ANALYSES - SAMPLES OF PURULENT MATERIAL, FLUID, OR SCRAPINGS FROM LESIONS

 

CLINICAL PROCEDURES

 

·        CRYOSURGERY - USE OF COLD LIQUID NITROGEN TO DESTROY TISSUE

 

·        SKIN TESTING

    

     1.     PATCH - SUSPECTED ALLERGY-CAUSING SUBSTANCE PUT ON GAUZE OR FILTER PAPER AND APPLIED TO THE SKIN.  POSITIVE IF BECOMES REDDENED OR SWOLLEN

 

     2.     SCRATCH - SMALL AMOUNT OF TEST MATERIAL INSERTED INTO SKIN SCRATCHES. POSITIVE IF RED OR SWOLLEN

 

3.          INTRADERMAL - INJECTION OF TEST MATERIAL BETWEEN LAYERS OF SKIN. WATCH FOR REACTION AS ABOVE.

 

INTEGUMENTARY SYSTEM

 

 

SOFTENING OF NAILS     ____________________

 

 

INFLAMMATION OF SWEAT

GLANDS     ____________________

 

 

ABNORMAL SKIN CONDITION

CAUSED BY DUST     ____________________

 

 

EXCISION OF A NAIL     ____________________

 

 

SURGICAL REPAIR OF SKIN     ____________________

 

 

INSTRUMENT TO CUT SKIN     ____________________

 

PERTAINING TO WITHIN

THE SKIN     ____________________

 

 

PERTAINING TO UNDER

THE SKIN     ____________________

 

PERTAINING TO ABOVE

THE SKIN     ____________________