Chapter 9 Skin, hair, and nails

Question 1

Skin functions

Answer 1

• Protection against microbes and minor physical trauma
• Prevent fluid loss
• Regulate body temperature
• Provide sensory perception via free nerve endings

Question 2

Epidermis

Answer 2

Outermost part of the skin. Contains no blood vessels and relies on the dermis for nutrition

Question 3

Stratum corneum

Answer 3

Protects the body against harmful environmental substances and prohibits water loss.

Question 4

Cellular stratum

Answer 4

where keratin cells are synthesized

Question 5

Dermis

Answer 5

Richly vascular connective tissue layer of the skin that supports and separates the epidermis from adipose tissue. Consist of sensory nerve fibers that provide sensations to the body.

Question 6

Hypodermis

Answer 6

Connects dermis to organs. Has an adipose layer which generates heat, provides insulation and shock absorption and a calorie reserve.

Question 7

Eccrine sweat glands

Answer 7

Open directly onto the surface of the skin and regulate body temperature though sweat secretion. Found throughout the body except the lip margins, ear drums, nail beds, inner surface of foreskin and tip of the penis

Question 8

Apocrine sweat glands

Answer 8

Secrete an oily fluid that consists of protein, carbohydrates and other substances. Only found in the axillae, nipples, areolae, anogenital area, eyelids, and external ears. Secretion from these glands are orderless and body odor is produced by bacterial decomposition of apocrine sweat.

Question 9

Sebaceous glands

Answer 9

Secrete sebum a lipid-rich substance that prevents the skin and hair from drying out.

Question 10

Vellus hair

Answer 10

Short, fine soft, and nonpigmented

Question 11

Terminal hair

Answer 11

is coarser, longer, thicker and is usually pigmented

Question 12

Nails

Answer 12

Made of epidermal cells that a converted to hard plates of keratin. The nail plate sits on on the highly vascular nail bed giving the nail its pink color

Question 13

Primary skin lesions

Answer 13

develop as a direct result of a disease process

Question 14

Secondary skin lesions

Answer 14

evolve from primary lesions or develop as a consequence of a patient’s activities

Question 15

Macule

Answer 15

Primary skin lesion: A flat area that is a change in the color of the skin; less than 1cm in diameter
Examples: Freckles, flat moles (nevi), petechiae, measles

Question 16

Papule

Answer 16

Primary skin lesion: An elevated FIRM, circumscribed area; less than 1cm in diameter
Examples: Warts, elevated moles, lichen planus

Question 17

Patch

Answer 17

Primary skin lesion: FLAT, non-palpable, irregular shaped macule GREATER than 1cm in diameter.
Examples: Vitiligo, port-wine stains, hyper pigmented macule, cafe au lait patch

Question 18

Plaque

Answer 18

Primary skin lesion: ELEVATED, FIRM, and rough lesion with flat top surface GREATER than 1 cm in diameter
Examples: Psoriasis, seborrheic, and actinic keratosis

Question 19

Nodule

Answer 19

Primary skin lesion: ELEVATED, FIRM circumscribed lesion DEEPER in dermis than papule; 1-2 cm in diameter
Examples:Erythema nodosum, lipoma

Question 20

Bulla

Answer 20

Primary skin lesion: Vesicle (fluid filled) greater than 1cm in diameter
Examples: Blister, pemphigus vulgaris

Question 21

Pustule

Answer 21

Primary skin lesion: ELEVATED, superficial lesion; similar to a vesicle but FILLED with purulent fluid.
Examples: Impetigo, acne

Question 22

Wheal

Answer 22

Primary skin lesion: ELEVATED, IRREGULAR shaped area of cutaneous edema; solid transient, varies in diameter
Examples: Insect bites, urticaria and allergic reaction

Question 23

Cyst

Answer 23

Primary skin lesion: ELEVATED circumscribed, encapsulated lesion; in dermis or subcutaneous layer; filled with liquid or semisolid material
Examples: Sebaceous cyst, cystic acne

Question 24

Scale

Answer 24

Secondary skin lesion: Heaped-up, keratinized cells; flaky skin; irregular; thick or thin dry or oily; varies in size.
Examples: Flaking of skin with seborrheic dermatitis or after a drug reaction that causes dry skin

Question 25

Crust

Answer 25

Secondary skin lesion: Dried serum, blood or purulent exudates; slightly elevated; varies in size; can be brown, red, black, tan, or straw colored.
Examples: Scab on abrasion, eczema

Question 26

Fissure

Answer 26

Secondary skin lesion: Linear crack or break from the epidermis to the dermis; may be moist or dry
Examples: Athlete’s foot, cracks at the corner of the mouth

Question 27

Erosion

Answer 27

Secondary skin lesion: Loss of part of the epidermis; depressed, moist glistening; follows rapture of a vesicle or bulla

Question 28

Ulcer

Answer 28

Secondary skin lesion: Loss of epidermis and dermis; concave; varies in size
Examples: Decubiti, stasis ulcers

Question 29

Lichenification

Answer 29

Secondary skin lesion: Rough, thickened epidermis secondary to persistent rubbing, itching or skin irritation; often involves flexor surface of extremity
Examples: Chronic dermatitis

Question 30

Scar

Answer 30

Secondary lesion: Thin to thick fibrous tissue that replaces normal skin after injury or laceration to the dermis

Question 31

Keloid

Answer 31

Secondary skin lesion: Irregularly shaped, elevated, progressively enlarging scar; grows beyond the boundaries of the wound; caused by excessive collagen formation during healing.

Question 32

Excoriation

Answer 32

Secondary skin lesion: Loss of epidermis; linear hollowed-out crusted area
Examples: Abrasion or scratch, scabies