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INTEGUMENTARY
SYSTEM
CHAPTER
16: SKIN
FUNCTIONS OF THE SKIN
Protects the body –prevents loss of
water, salt, heat & against invasion of
pathogens & toxins
Lubricates skin surface (with sebum,
secreted from sebaceous glands)
Maintains temperature
1.
2.
3.
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4.
Cools body by evaporation (with sweat
secreted from sweat glands)
Has blood vessels that dilate & constrict
Has nerve fibers under the skin that
aid in sensations of pain, pressure,
touch, and temperature
LAYERS OF SKIN
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Epidermis – outermost layer
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Corium (Dermis) – middle layer between epidermis
and subcutaneous layer
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Basal layer - deepest layer of epidermis
Stratum Corneum – cells are called “horny cells” or
keratinized cells, outermost layer of epidermis
Lacks blood & lymph vessels & connective tissue
Contains blood & lymph vessels, hair follicles, glands,
and nerve fibers
Has connective tissue cells & elastic collagen fibers
Subcutaneous – innermost layer
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Lipocytes (fat cells) mostly present; help to act as a
heat insulator and for energy storage
Stratum corneum
Basal layer
melanocytes
Epidermis
Dermis
Subcutaneous
tissue
You will need to be able to locate and/or identify individual layers
of skin
ACCESSORY ORGANS OF SKIN
Hair – tight network of horny cells filled with
keratin & melanocytes; keratin production
determines hair color
Nails – hard keratin plates composed of
horny cells
Glands
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Sebaceous – located all over the body except
palms of hands and soles of feet, produce
sebum to lubricate skin
Sweat – coiled gland most numerous on palms
of hands & soles of feet, sweat is a mixture of
water and salt, functions to cool the body
Figure 16-2. (A) Anatomical structure of a nail. (B) Onycholysis. Infection or trauma to the nail
may be the cause of the detachment of the nail from its plate. (B from Seidel HM: Mosby's Guide to
Physical Examination, 5th ed. St. Louis, Mosby, 2003, p. 214.)
COMBINING FORMS RELATED TO SKIN
diaphor / o = sweat
diaphor / esis = profuse sweating condition
hidr / o = sweat
an / hidr / osis = condition of not sweating
ichthy / o = dry, scaly
ichthy / osis = dry, scaly skin
myc / o = fungus
dermat / o / myc / osis = fungal skin inf
onych / o = nail
onych / o / myc / osis = fungus in nail
trich / o = hair
trich / o / myc / osis = fungus in hair
xer / o = dry
xer / o / derma = dry skin
ungu / o = nail
sub / ungu / al = under the nail
adip / = fat
adip / ose = pertaining to fat
albin / o = white
albin / ism = condition of white (skin)
kerat / o = hard, horny tissue kerat / osis = abnormal condition of ……
xanth / o = yellow
xanth / oma = yellow mass (tumor)
melan / o = black
melan / oma = black tumor
seb / o = oily (sebum)
seb/ o / rrhea = oily discharge
TYPES OF SKIN LESIONS
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Cyst – thick walled, closed sac or pouch
containing fluid or semi-solid material
Fissure – groove or crack-like sore
Macule – discolored (often red) flat lesion
TYPES OF SKIN LESIONS
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Papule – small solid elevation of the skin
Polyp – mushroom like growth extending on stalk from
surface of mucous membrane
Pustule – small elevation in skin containing pus
Ulcer – open sore on skin or mucous membrane
Decubitus ulcer – bedsore, from staying in one position
Vesicle – small collection of clear fluid, blister
Wheal – smooth, slightly
elevated swollen area
that is more red or pale
than surrounding skin
(also called hive)
BULLAE
Figure 16-4. Bullae (large blisters) in bullous pemphigoid (a chronic skin disorder in older
individuals). The pemphigoid (pemphix means bubble) bullae occur as the entire thickness of the
epidermis detaches from its foundation. (From Kumar V, Cotran RS, Robbins SL: Basic Pathology,
7th ed. Philadelphia, WB Saunders, 2003, p. 797.)
ABNORMAL SKIN SYMPTOMS
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Alopecia – absence of hair
from areas where hair
normally grows
Pruritis – itching associated
with many skin conditions
Urticaria – hives; acute
allergic reaction where red,
round wheals develop on skin
Figure 16-5. Dermatologic signs.
(A) Alopecia areata.
(B) Ecchymoses, right hand.
(C) Petechiae.
(D) Senile purpura. Fragile blood vessels
rupture with minimal trauma.
(E) Urticaria
ABNORMAL SKIN CONDITIONS
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Impetigo – characterized by
vesicles, pustules, and crusted
over lesions; Rx – antibiotics
and proper handwashing
Scabies – accompanied by
severe itching; Rx – topical
medications to
destroy mites
ABNORMAL SKIN CONDITIONS
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Tinea – named by location,
Rx for all: antifungals
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corpus – body, commonly
called ringworm
tinea pedis – feet, commonly
called athletes foot
tinea barbae – under a beard
tinea capitis – on the scalp
Figure 16-9. (A) Tinea corporis (ringworm).
(B) Tinea unguium. Fungal infection of the nail
causes the distal nail plate to turn yellow or
white. Hyperkeratotic debris accumulates,
causing the nail to separate from the nail bed
(onycholysis).
ABNORMAL SKIN CONDITIONS
Wart – verruca is medical term for wart
Figure 16-12. Verruca
vulgaris. Warts are
multiple papules with
rough, pebble-like
surfaces.
ACNE
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Acne – papular and
pustular lesions of the
skin
Figure 16-6. (A) Formation of a
blackhead (comedo) in a dilated
pore filled with sebum, bacteria, and
pigment. (B) Acne vulgaris on the
face.
ABNORMAL SKIN CONDITIONS
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Eczema – inflammatory skin disease with red,
pepulovesicular lesions
Psoriasis – chronic condition; itchy, scaly, red
plaques on the skin covered by silvery grey scales
Figure 16-8. Psoriasis. Scaly erythematous
plaque, with silvery scales on top.
ABNORMAL SKIN CONDITONS
Figure 16-10. Vitiligo on the hand (Latin: vitium meaning a 'blemish').
Epidermal melanocytes are completely lost in depigmented areas
through an autoimmune process.
Figure 16-11. (A) Callus on the sole of the foot. (B) Keloid. (A from Mosby's Medical, Nursing, and Allied
Health Dictionary, 6th ed., St. Louis, Mosby, 2002, p. 265; B from Ignatavicius DD, Workman ML: MedicalSurgical Nursing: Critical Thinking for Collaborative Care, 4th ed. Philadelphia, WB Saunders, 2002, p.
1544.)
ABNORMAL SKIN CONDITIONS
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Cellulitis – acute infection of skin marked by heat,
redness, pain, and swelling; Rx: antibiotics
Gangrene – death of tissue from loss of blood
supply
BURNS
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First degree – superficial burn,
affecting epidermal layer of skin,
skin is red and dry; Ex – sunburn
Second degree – affecting
epidermal and dermal layers;
skin is red and has blisters; Ex burn from cooking
Third degree – epidermal and
dermal layers destroyed,
subcutaneous tissue damaged,
charred white, grey and/or black
tissue
Figure 16-7. Burns. (A) Second-degree injury. Wound sensation is painful and very sensitive to
touch and air currents. (B) Third-degree burn showing viable color (deep-red, white, black and
brown). The wound itself is insensate (does not respond to pinprick sensation).
ABNORMAL SKIN CONDITIONS
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Actinic Keratosis –
precancerous skin lesion
(usually caused by sun
exposure)
Squamous Cell Carcinoma malignant tumor of squamous
epithelial cell of epidermis,
remember epithelial cells also
line internal organs so you
can have squamous cell
carcinoma in the mouth,
larynx, lung, etc…
Figure 16-15. (A) Actinic (solar) keratosis.
(B) Squamous cell carcinoma. Lesions are often nodular
and ulcerated.
ABNORMAL SKIN
CONDTIONS
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Basal Cell Carcinoma –
malignant tumor of
basal cell layer of
epidermis
Karposi’s Sarcoma tumors develop in the
tissues below the skin
surface, or in the
mucous membranes.
Common in HIV+
patients
Figure 16-13.
(A) Basal cell carcinoma.
(B) Kaposi sarcoma.
ABNORMAL SKIN CONDITIONS
The ABCDs of melanoma.
(A)Asymmetry: one half
unlike the other half.
(B) Border: irregular or
poorly circumscribed
border.
(C)Color: varied from one
area to another; shades of
tan & brown; black;
sometimes white, red or
blue.
(D)Diameter: usually larger
than 6mm (diameter of a
pencil eraser).