Brief information from Chapter 7
Figure 7-1 • Integumentary system.
The integumentary system covers the entire surface of the body and consists of the skin, hair, and nails.
Figure 7-2 • Epidermis and dermis.
The skin is composed of the epidermis and the dermis. The epidermis contains dead protective cells on its surface and living, actively dividing cells at its base. The dermis contains hair follicles, sebaceous glands, and sweat glands. The subcutaneous tissue, a type of connective tissue, lies beneath the dermis.
Figure 7-3 • Dermatomes of the body.
A dermatome is a specific area of the skin that sends sensory information through a spinal nerve to the spinal cord. Each dermatome is named according to the level at which the spinal nerve enters the spinal cord. C stands for the spinal cord at the level of the neck (the combining form cervic/o- means neck). T stands for the spinal cord at the level of the thorax. L stands for the spinal cord at the level of the lower back. S stands for the spinal cord at the level of the sacrum (last bone in the spinal column). The skin of the face sends sensory information through the cranial nerves to the brain.
Figure 7-4 • Nail.
The nail is composed of both living and dead cells. The nail root produces keratin-containing cells that form the lunula. As the nail plate grows, these cells die and harden to form a protective covering for the distal end of the finger.
Figure 7-5 • Edema.
Fingertip pressure on an area of severe edema displaces the fluid and produces a deep indentation in the tissues. This is known as pitting edema.
Figure 7-6 • Types of skin lesions.
Figure 7-7 • Necrosis and pallor.
This patient’s ring finger has necrosis and gangrene due to severe frostbite. The ring finger has been marked to show the location where an amputation will be performed. The tips of the index and little fingers show pallor, indicating poor blood flow.
Meyer/Custom Medical Stock Photo, Inc.
Figure 7-8 • Vitiligo.
This patient has areas of depigmentation on each hand due to vitiligo, a progressive autoimmune disease.
Custom Medical Stock Photo
Figure 7-9 • Second-degree burn of the hand.
The burn caused the epidermis to separate from the dermis. Tissue fluid caused the epidermis to swell into large, fluid-filled bullae.
Logical Images, Inc.
Figure 7-10 • Keloid.
A keloid is a scar that continues to grow until it is larger than the original injury. Depending on its location and size, a keloid can be cosmetically unacceptable.
Custom Medical Stock Photo,Inc.
Figure 7-11 • Decubitus ulcer.
This stage III decubitus ulcer involves the loss of the epidermis, dermis, and subcutaneous tissue, exposing the muscle layer.
Custom Medical Stock Photo, Inc.
Figure 7-12 • Laceration.
This deep laceration of the forearm was caused by a piece of glass that penetrated through the epidermis and dermis to the adipose tissue in the subcutaneous layer.
Gill/Custom Medical Stock Photo, Inc.
Figure 7-13 • Shingles.
The vesicles and crusts of shingles. The lesions occur along a dermatome.
Gill/Custom Medical Stock Photo, Inc.
Figure 7-14 • Tinea pedis.
This fungal infection, also known as athlete’s foot, causes severe itching and burning. The erythematous, scaly lesions become soft and white and begin to peel due to moisture between the toes.
SPL/Photo Researchers, Inc.
Figure 7-15 • Severe contact dermatitis.
This skin reaction was caused by the application of a new deodorant whose chemical ingredients caused irritation.
SPL/Photo Researchers, Inc.
Figure 7-16 • Hemangioma.
The bright red color of this skin lesion comes from the large number of dilated blood vessels.
Custom Medical Stock Photo, Inc.
Figure 7-17 • Nevus.
A mole is a pigmented nevus that can be flat or round and elevated and often contains a hair.
Figure 7-18 • Senile lentigo.
These light brown macules occur with age and are called age spots or liver spots.
Figure 7-19 • Syndactyly.
The skin and soft tissues of the second and third toes are fused together in this patient with syndactyly.
Figure 7-20 • Malignant melanoma.
This lesion reveals three of the four typical characteristics of a malignant melanoma: asymmetry; irregular edges; and varying shades of color. The fourth characteristic—an increase in size—would be noted over time.
ISM/Phototake NYC
Figure 7-21 • Kaposi’s sarcoma.
This previously rare cancer is now commonly seen in AIDS patients because of their impaired immune response. The cancer involves the skin, mucous membranes, and internal organs.
Zeva Oelbaum/Peter Arnold, Inc.
Figure 7-22 • Psoriasis.
Psoriasis produces characteristic elevated, erythematous lesions that are topped by silvery scales and plaques.
NMSB/Custom Medical Stock Photo, Inc.
Figure 7-23 • Acne vulgaris.
This adolescent boy has severe acne vulgaris with papules, comedos, and pustules. Increased secretion of the sebaceous glands during puberty triggers the onset of acne vulgaris.
Clinical Dermatology: A Color Guide to Diagnosis and Therapy, 2nd ed., by T.P. Habif, 1990, St. Louis: Mosby Year Book
Figure 7-24 • Acne rosacea.
This patient’s face shows the blotchy, rose-colored erythema and dilated superficial blood vessels of acne rosacea. Even the eyelids and neck are affected.
Clinical Dermatology: A Color Guide to Diagnosis and Therapy, 2nd ed., by T.P. Habif, 1990, St. Louis: Mosby Year Book
Figure 7-25 • Onychomycosis.
This fungal infection can involve one or all of the nails of the hands or feet. The nail is discolored, misshapen, thickened, and raised up from the nail bed.
Logical Images/Custom Medical Stock Photo, Inc.
Figure 7-26 • Allergy skin testing.
This patient’s forearm shows a number of wheals where the body’s immune response was triggered by the injected antigen. The size of the wheal corresponds to the degree of allergy to that antigen. No wheal formation means that the patient is not allergic to that antigen.
SIU/Photo Researchers, Inc.
Figure 7-27 • Botox injection.
The drug Botox is actually a diluted neurotoxin from the bacterium Clostridium botulinum type A that causes food poisoning (botulism) and is present in canned goods with bulging ends.
Suzanne Dunn/The Image Works
Figure 7-28 • Skin examination.
This dermatologist is using a magnifying lens and strong light to examine a lesion on this patient’s skin. The area may need to be biopsied to obtain a diagnosis.
AJ Photo/Photo Researchers, Inc.
Figure 7-29 • Layered closure with sutures.
After an anesthetic drug was given to numb the area, this laceration in the forearm was sewn closed with two layers of sutures, the first in the deeper tissues and the second to close the skin edges. After a week, the skin sutures were removed. The deeper sutures, which were made of a material that was absorbed by the body, did not need to be removed.
Figure 7-30 • Liposuction.
This surgeon is performing liposuction to reduce the size of a breast. This is a plastic surgery procedure that is known as a breast reduction or mammoplasty. Both breasts will be done to achieve a symmetrical result.
James King-Holmes/D. Mercer/Photo Researchers, Inc.
Figure 7-31 • Skin graft.
A skin graft is so thin that the physician’s gloved hands can be seen through it. The graft is kept in a sterile container until it is applied to the patient’s skin.
Courtesy Martin R. Eichelberger, M.D., Children’s National Medical Center, Washington, DC