Jarvis: Physical Examination and Health Assessment, 8th Edition
Chapter 13: Skin, Hair, and Nails
Answer Keys: Study Guide and Lab Manual
1. The three layers are as follows:
 Epidermis: the outer, highly differentiated, yet thin layer that forms a protective barrier.
 Dermis: the inner, supportive layer that consists mainly of connective tissue (collagen),
which is tough, fibrous protein that helps the skin to resist tearing. This layer contains
nerves, sensory receptors, blood vessels, and lymphatics as well as hair follicles,
sebaceous glands, and sweat glands.
 Subcutaneous: the adipose tissue layer that stores fat for energy, provides insulation for
temperature control, and aids in protection with its cushioning effect.
2. The differences between the glands are as follows:
 Sebaceous glands produce sebum, a protective lipid substance that lubricates the skin and
hair and forms an emulsion with water that retards water loss from the skin. These
glands are located mostly on the scalp, forehead, face, and chin. Eccrine glands are
sweat glands that are widely distributed through the body and are mature by the time an
infant is 2 months old. The sweat that is produced from these glands is a dilute saline
solution; its evaporation reduces body temperature.
 Apocrine glands are sweat glands that are located mainly in the axillae, anogenital area,
nipples, and navel. They become active during puberty, and produce a thick, milky
secretion and open into the hair follicles. Bacterial flora from the skin surface reacts
with apocrine sweat and produces the characteristic musty body odor.
3. The functions include the following:
 Protection.
 Prevents penetration.
 Perception.
 Temperature regulation.
 Identification.
 Communication.
 Wound repair.
 Absorption and excretion.
 Production of vitamin D.
4. See Table 13.2, Detecting Color Changes in Light and Dark Skin.
5. The causes include the following:
 Changes in skin temperature: hypothermia, hyperthermia, hyperthyroidism.
 Changes in skin texture: hyperthyroidism, hypothyroidism.
 Changes in skin moisture: diaphoresis due to an increased metabolic rate (thyrotoxicosis,
fever, heavy activity), stimulation of the nervous system (anxiety, pain), or dehydration.
 Changes in skin mobility: edema and scleroderma cause decreased mobility.
 Changes in skin turgor: poor turgor occurs in severe dehydration.
6. Leukonychia striata.
7. Common variations include the following:
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Answer Keys: Study Guide and Lab Manual

13-2
Mongolian spot: a common variation of hyperpigmentation in black, Asian, Native
American, and Hispanic newborns. It is a blue-black to purple macular area at the
sacrum or buttocks, but sometimes also occurs on the abdomen, thighs, shoulders, or
arms. It gradually fades over the first year to adulthood. See Fig. 13.17.
 Café au lait spot: a large, round or oval patch of light brown pigmentation that is usually
present at birth. See Fig. 13.18.
 Erythema toxicum: a common rash that appears in the first 3 to 4 days of life and consists
of tiny punctate red macules and papules on the cheeks, trunk, chest, back, and buttocks.
The cause is unknown, and no treatment is needed. See Fig. 13.19.
 Cutis marmorata: a transient mottling in the trunk and extremities in response to cool
room temperatures. It forms a reticulated red or blue pattern over the skin. See Fig.
13.20.
 Physiologic jaundice: a yellowing of the skin, sclera, and mucous membranes that
develops after the third or fourth day of life and is due to red blood cell hemolysis that
occurs after birth. When the Hb of the destroyed red blood cells is metabolized by the
liver and spleen, its pigment is converted to bilirubin.
 Milia: tiny white papules on the cheeks, forehead, and across the nose and chin due to
sebum that occludes the opening of the follicles. This is a common variation that
resolves spontaneously within a few weeks. See Fig. 13.21.
8. The differences in aging skin include the following:
 Senile lentigines: “liver spots,” small, flat brown macules that are not malignant and
require no treatment. See Fig. 13.25.
 Seborrheic keratosis: dark, greasy, raised, thickened areas of pigmentation that look
“stuck on” the skin. They develop mostly on the trunk but also on the face and hands.
See Fig. 13.26.
 Actinic keratosis: also known as senile or solar keratosis, are red-tan scaly plaques that
increase over the years to become raised and roughened; they may have a silvery-white
scale adherent to the plaque, and are premalignant. See Fig. 13.27.
 Acrochordons (skin tags): overgrowths of normal skin that form a stalk and are polyplike;
they occur frequently on the eyelids, cheeks, neck, axillae, and trunk. See Fig. 13.28.
 Sebaceous hyperplasia: raised, yellow papules with a central depression and a pebbly
look. See Fig. 13.29.
9. The differences are as follows:
 Petechiae: tiny punctate hemorrhages, less than 2 mm, round, and discrete, dark red,
purple, or brown. See photograph in Table 13.7, Vascular Lesions.
 Ecchymosis: a large patch of capillary bleeding into the tissues (bruise). See Table 13.7,
Vascular Lesions.
 Contusion: (a bruise) a hemorrhage into tissues. See Table 13.7, Vascular Lesions.
10. Rashes include the following:
 Measles (rubeola): red-purple maculopapular blotchy rash that appears on the third or
fourth day of illness and appears first behind the ears and spreads over the face, then
over the neck, trunk, arms, and legs. The rash does not blanch, and Koplik spots may be
present in the mouth. For more description, see Table 13.8, Common Skin Lesions in
Children.
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Answer Keys: Study Guide and Lab Manual

13-3
German measles (rubella): pink, papular rash (similar to measles but more pale) that first
appears on the face, then spreads. No Koplik spots. See Table 13.8, Common Skin
Lesions in Children.
 Chickenpox (varicella): small, tight vesicles that first appear on the trunk, then spread to
the face, arms, and legs. Shiny vesicles with an erythematous base develop and are
commonly described as a “dewdrop on a rose petal.” The vesicles erupt in succession
over several days, then become pustules, then crusts. The vesicles are highly pruritic.
See Table 13.8, Common Skin Lesions in Children.
11. The four stages of pressure injury development include the following:
Stage I: Intact skin appears red but unbroken. Localized redness in lightly pigmented skin
will blanch (turns light with fingertip pressure). Dark skin appears darker but does not
blanch.
Stage II: Partial-thickness skin erosion with loss of epidermis or also the dermis. Superficial
ulcer looks shallow like an abrasion or open blister with a red-pink wound bed.
Stage III: Full-thickness pressure ulcer extending into the subcutaneous tissue and
resembling a crater. May see subcutaneous fat but not muscle, bone, or tendon.
Stage IV: Full-thickness pressure ulcer involves all skin layers and extends into supporting
tissue. Exposes muscle, tendon or bone, and may show slough (stringy matter attached to
wound bed) or eschar (black or brown necrotic tissue). (See Table 13.6.)
12. See Table 13.4, Primary Skin Lesions, and Table 13.5, Secondary Skin Lesions.
Labeling Exercises:

See Fig. 13.1.

See Fig. 13.2.
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