The Language Of Medicine 9th edition Davi-Ellen Chabner

Chapter 16 Skin

Chapter Goals Name the layers of the skin and the accessory structures associated with the skin. Build medical words using the combining forms that are related to the specialty of dermatology. Identify lesions, signs, and symptoms, and pathologic conditions that relate to the skin.

Chapter Goals (cont’d) Describe laboratory tests and clinical procedures that pertain to the skin and recognize relevant abbreviations. Apply your new knowledge to understanding medical terms in their proper contexts, such as medical reports and records.

Chapter 16 Lesson 16.1

Introduction Skin: integumentary system weighs 8 to10 lbs. covers 22 sq. ft. in average adult What tissues can you predict will be integrated into this organ system? What are the unique qualities of epithelium that make it a suitable tissue for covering the body? How is the epithelium on the “outside” (part of the skin) similar to that on the inside of the body?

Functions of Skin Provides protective membrane Skin glands lubricate and cool the skin Receptor for sensations Helps maintain body temperature Have students define desiccation. Ask them to list three ways that skin guards against desiccation. How does skin guard against acidic secretions?

Functions of Skin (cont’d) Produces sweat: sweat glands produce watery secretion that evaporates and cools Produces sebum: sebaceous glands produce oily secretion that lubricates skin and hair Receives sensation: pain, temperature, pressure, and touch Thermoregulates: interprets message from heat center in the brain Ask the students to define the word thermoregulate. How does the skin thermoregulate? There are multiple mechanisms for thermal control. Describe at least three or four.

Structure of the Skin Epidermis: outermost, thin cellular membrane Dermis: next layer; dense fibrous, connective tissue Subcutaneous tissue (hypodermis): thick, fat-containing tissue What does the epidermis lack? Ask the students to describe what it is dependent upon. What is the dermis composed of? Ask the students to describe what supports this layer. Ask the students what lipocytes are and where they are found.

Structure of the Skin (cont’d) In the inset of this picture (B) you can see what are called dermal papillae. They look like wavy folds. What is the advantage of this kind of tissue architecture? The dermis appears to be pushing up folds into the epidermis. Why? Is the epithelium vascular? Why is that an advantage or disadvantage?

Structure of the Skin (cont’d) In the inset of this picture (B) you can see what are called dermal papillae. They look like wavy folds. What is the advantage of this kind of tissue architecture? The dermis appears to be pushing up folds into the epidermis. Why? Is the epithelium vascular? Why is that an advantage or disadvantage?

Acessory Organs of the Skin HAIR: cells filled with the hard protein; keratin Hair follicles: shafts that hold the hair Five million hairs on body; 100,000 on head Melanocytes at the root form the color Grow .5 inch (1.3 cm) per month Cutting does not affect growth Ask the students to describe melanocytes and where they can be found. What functions does hair have? (sensory, thermoregulation)

Accessory Organs of the Skin (cont’d)

Accessory Organs of Skin (cont’d) NAILS: hard keratin plates covering toes and fingers lunula cuticle paronychium How are hair, nails, and epidermis alike? How do these structures grow and slough off cells?

Accessory Organs of Skin (cont’d) GLANDS: sebaceous and sweat Sebaceous glands secrete oily sebum into hair follicle to lubricate. Sweat glands secrete into pores to moisten and cool. Both are subject to bacterial growth. Why do people have so many sweat glands? Could people live without sweat glands? Do sebaceous glands make hair feel oily?

Accessory Organs of Skin (cont’d) Sebaceous gland, eccrine sweat gland, and apocrine sweat gland. Why do people have so many sweat glands? Could people live without sweat glands? Do sebaceous glands make hair feel oily?

Combining Forms adip/o fat albin/o white caus/o burn, burning cauter/o heat, burn cutane/o skin derm/o/ skin Combining Form Meaning

Combining Forms (cont’d) dermat/o skin diaphor/o profuse sweating erythem/o redness erythemat/o redness hidr/o sweat ichthy/o scaly, dry Combining Form Meaning

Combining Forms (cont’d) kerat/o hard, horny tissue leuk/o white lip/o fat melan/o black myc/o fungus onych/o nail Combining Form Meaning

Combining Forms (cont’d) phyt/o plant pil/o hair, hair follicle py/o pus rhythid/o wrinkle seb/o sebum squam/o scalelike Combining Form Meaning

Combining Forms (cont’d) steat/o fat trich/o hair ungu/o nail xanth/o yellow xer/o dry Combining Form Meaning

QUICK QUIZ: Which combining form refers to white? chlor/o jaund/o melan/o albin/o Correct answer is D: albin/o means white as in albinism

QUICK QUIZ: (cont’d) Which combining form refers to the same color as jaund/o? xanth/o chlor/o erythr/o cyan/o Correct answer is A: xanth/o means yellow as in xanthoma

Colors

Chapter 16 Lesson 16.2

Cutaneous Lesions Label the lesions What is the definition of a lesion? Which of these lesions are similar but are differentiated by size? Which lesions involve the dermis layer?

Cutaneous Lesions (cont’d) Review the lesions What is the definition of a lesion? Which of these lesions are similar but are differentiated by size? Which lesions involve the dermis layer?

Signs and Symptoms Alopecia: absence of hair where it normally grows What are some causes of alopecia? Are there any treatments for baldness? Are they successful? Another form of alopecia is a result of trichotillomania, or obsessive hair-pulling.

Signs and Symptoms (cont’d) Ecchymosis: blue-black marks on the skin What can cause ecchymosis? What is the treatment?

Signs and Symptoms (cont’d) Petechia: small pinpoint hemorrhage Use the pictures as examples. Ask students whether they have ever been diagnosed with any of the skin conditions mentioned. What diseases are associated with these symptoms? What is pruritus? What is purpura?

Signs and Symptoms (cont’d) Urticaria: acute allergic reaction with red, round wheals on skin What is the common term for urticaria? Have students discuss their experiences (or that of someone they know) with hives. What causes hives? How long do they last?

Abnormal Conditions Acne: papular and pustular eruption of skin with increased production of sebum What is the medical term for a blackhead? Why are adolescents so prone to acne? Myths and reality. Are over-the-counter treatments effective?

Abnormal Conditions (cont’d) Burns: injury to tissue due to heat, chemical, electric shock, lightning or radiation. Image shows (A) Second degree burn and (B) Third degree burn. Go over the different degrees of burns and use a chart with the layers of the skin to demonstrate how deep the burns go. What percentage of body burn results in death? Why?

Abnormal Conditions (cont’d) Cellulitis: diffuse acute infection of skin Eczema: inflammation of skin with erythematous and papulovesicular lesions caused by allergy Exanthematous viral diseases: rash due to virus (for example, rubella) Gangrene: death of tissue with loss of blood supply Which of these diseases is/are common in children? Why? What are other diseases that are similar to eczema? Are they all treated in the same way?

Abnormal Conditions (cont’d) Impetigo: contagious pyoderma caused by staph or strep Psoriasis: chronic recurrent dermatosis with silver gray scales that itch Scabies: parasitic (tiny mites) and infectious pruritus Scleroderma: chronic and progressive disease of skin with hardening of connective tissue Which of these diseases are NOT contagious? Which disease may worsen if the patient experiences anxiety?

Abnormal Conditions (cont’d) Systemic lupus erythematosus (SLE): inflammatory disease of collagen in skin, joints, and internal organs What are the current thoughts about the origin of SLE? How is it treated? Where have we discussed it before because of other organ systems it affects?

Abnormal Conditions (cont’d) Tinea: infection of the skin caused by fungus Tinea corporis Tinea unguium What is tinea? (fungal infection of skin or nails, that is, ringworm, athlete’s foot)

Abnormal Conditions (cont’d) Vitiligo: Loss of pigment in areas of skin Vitiligo What is vitiligo? (loss of pigment in areas of skin causing milk-white patches)

Chapter 16 Lesson 16.3

Skin Neoplasms — Benign Callus Keloid What is a callus? (increased growth of cells in keratin layer of epidermis due to friction against skin) What is a keloid? (hypertrophied, thickened scar after trauma or surgery) Ask for student examples of places that commonly develop calluses. Why? Some people who are prone to keloids are discouraged from having their ears pierced.

Skin Neoplasms — Benign (cont’d) Keratosis: thickened area of epidermis Leukoplakia: white thickened patches on tongue or cheek Nevus: pigmented lesion Verruca: warts caused by virus Have students find images for abnormalities not shown in the text. Images are very useful for remembering these conditions.

Skin Neoplasms — Cancerous Basal cell carcinoma Malignant tumor of the basal cell layer of the epidermis Refer back to the chapter that included AIDS. Why are AIDS patients susceptible to this condition? Why does it rarely occur in the rest of the population?

Skin Neoplasms — Cancerous (cont’d) Squamous cell carcinoma Malignant tumor of the squamous epithelial cells of the epidermis. Refer back to the chapter that included AIDS. Why are AIDS patients susceptible to this condition? Why does it rarely occur in the rest of the population?

Skin Neoplasms — Cancerous (cont’d) The ABCDs of malignant melanoma. A. Asymmetry B. Border, irregular or circumscribed These skin tumors often metastasize to the lung, liver, bone, and brain. What is the current treatment for this type of cancer? Squamous cells can grow wherever there is squamous epithelium (internal or external). Common places include the mouth, larynx, bladder, esophagus, and lungs. Some are cigarette-related. Why are healthy organs lined with squamous cells in the first place? What about this tissue makes it appropriate for those particular organ systems? D. Diameter, usually larger than 6mm C. Color variation

Skin Neoplasms — Cancerous (cont’d) Kaposi sarcoma Malignant, vascular, neoplastic growth characterized by cutaneous nodules. Refer back to the chapter that included AIDS. Why are AIDS patients susceptible to this condition? Why does it rarely occur in the rest of the population?

Laboratory Tests Bacterial analyses: pus or fluid samples examined to detect microorganisms Fungal tests: scrapings for culture and microscopic examination after treatment with KOH

Clinical Procedures Cryosurgery: destroy tissue with subzero temperatures using liquid nitrogen Curettage: scrape lesion with sharp curet Electrodesiccation: destroy tissue by burning with electric spark For what conditions is electrodesiccation recommended?

Clinical Procedures (cont’d) Mohs surgery: remove thin layers of growth to examine under microscope (basal and squamous cell) Skin biopsy: punch and shave to remove for examination in path lab Skin test: test reaction of body to allergen with skin test (scratch or patch tests) Discuss how some of the surgeries are for both diagnosis and treatment. Removal is done whether or not the physician knows that the lesion is cancerous. All suspicious-looking tissues removed from the body are sent to the pathology lab for analysis. Why?

Abbreviations ABCDE asymmetry, border, color, diameter, evolution (or change) —characteristics associated with melanoma bx biopsy Derm. dermatology DLE discoid lupus erythematosus PPD purified protein derivative PUVA psoralen-ultravoilet A light therapy SLE systemic lupus erythematosus SC subcutaneous Ask students to provide the full terms for these abbreviations.

Review Sheet adip/o ___________ albin/o ___________ caus/o ___________ COMBINING FORMS adip/o ___________ albin/o ___________ caus/o ___________ cauter/o ___________ cutane/o ___________ derm/o ___________ Combining Form Meaning

Review Sheet (cont’d) adip/o fat albin/o white caus/o burn, burning COMBINING FORMS adip/o fat albin/o white caus/o burn, burning cauter/o heat, burn cutane/o skin derm/o skin Combining Form Meaning

Review Sheet (cont’d) dermat/o ___________ diaphor/o ___________ COMBINING FORMS dermat/o ___________ diaphor/o ___________ erythem/o ___________ erythemat/o ___________ hidr/o ___________ ichthy/o ___________ Combining Form Meaning

Review Sheet (cont’d) dermat/o skin diaphor/o profuse sweating COMBINING FORMS dermat/o skin diaphor/o profuse sweating erythem/o redness erythemat/o redness hidr/o sweat ichthy/o scaly, dry Combining Form Meaning

Review Sheet (cont’d) kerat/o ___________ leuk/o ___________ COMBINING FORMS kerat/o ___________ leuk/o ___________ lip/o ___________ melan/o ___________ myc/o ___________ onych/o ___________ Combining Form Meaning

Review Sheet (cont’d) kerat/o hard, horny tissue leuk/o white COMBINING FORMS kerat/o hard, horny tissue leuk/o white lip/o fat melan/o black myc/o fungus onych/o nail Combining Form Meaning

Review Sheet (cont’d) phyt/o ___________ pil/o ___________ COMBINING FORMS phyt/o ___________ pil/o ___________ py/o ___________ rhythid/o ___________ seb/o ___________ sabace/o ___________ squam/o ___________ Combining Form Meaning

Review Sheet (cont’d) phyt/o plant pil/o hair, hair follicle py/o pus COMBINING FORMS phyt/o plant pil/o hair, hair follicle py/o pus rhythid/o wrinkle seb/o sebum squam/o scale-like Combining Form Meaning

Review Sheet (cont’d) steat/o ___________ trich/o ___________ COMBINING FORMS steat/o ___________ trich/o ___________ ungu/o ___________ xanth/o ___________ xer/o ___________ Combining Form Meaning

Review Sheet (cont’d) steat/o fat trich/o hair ungu/o nail COMBINING FORMS steat/o fat trich/o hair ungu/o nail xanth/o yellow xer/o dry Combining Form Meaning

Review Sheet (cont’d) -algia ___________ -derma ___________ SUFFIXES -algia ___________ -derma ___________ -esis ___________ -lysis ___________ -ose ___________ Suffix Meaning

Review Sheet (cont’d) -algia pain -derma skin -esis condition SUFFIXES -algia pain -derma skin -esis condition -lysis breakdown; separation; destruction; loosening -ose full of; pertaining to; sugar Suffix Meaning

Review Sheet (cont’d) -osis ___________ -ous ___________ SUFFIXES -osis ___________ -ous ___________ -plakia ___________ -plasty ___________ -rrhea ___________ Suffix Meaning

Review Sheet (cont’d) -osis condition, usually abnormal SUFFIXES -osis condition, usually abnormal -ous pertaining to -plakia plaque -plasty surgical repair -rrhea flow; discharge Suffix Meaning