HEALTH ASSESMENT

SKIN

The skin is composed of three layers: the epidermis, dermis, and subcutaneous tissue (Fig. 13-1a). The skin is thicker on the palms of the hands and soles of the feet and is continuous with the mucous membranes at the orifices of the body. Subcutaneous tissue, which contains varying amounts of fat, connects the skin to underlying structures.

Epidermis

The epidermis (Fig. 13-1b), the outer layer of skin, is com- posed of four distinct layers: the stratum corneum, stratum lucidum, stratum granulosum, and stratum germinativum. The outermost layer consists of dead, keratinized cells that render the skin waterproof.

Dermis

⁃ The inner layer of skin is the dermis (see Fig. 13-1). It is con- nected to the epidermis by means of papillae. These papillae form the base for the visible swirls or friction ridges that provide the unique pattern of fingerprints with which we are familiar. Ridges also appear on the palms of the hands, the toes, and the soles of the feet.

Sebaceous Glands

⁃ The sebaceous glands (see Fig. 13-1a) develop from hair follicles and, therefore, are present over most of the body, exclud- ing the soles and palms. They secrete an oily substance called sebum that lubricates hair and skin and reduces water loss through the skin. Sebum also has some fungicidal and bacteri- cidal effects.

Sweat Glands

⁃ Sweat glands (see Fig. 13-1a) are of two types: eccrine and apocrine. The eccrine glands are located over the entire skin surface and secrete an odorless, colorless fluid, the evapora- tion of which is vital to the regulation of body temperature.

Subcutaneous Tissue

⁃ Merging with the dermis is the subcutaneous tissue, which is a loose connective tissue containing fat cells, blood vessels, nerves, and the remaining portions of sweat glands and hair follicles (see Fig. 13-1a).

HAIR

⁃ Hair consists of layers of keratinized cells and is found over much of the body except for the lips, nipples, soles of the feet, palms of the hands, labia minora, and penis. Hair develops within a sheath of epidermal cells called the hair follicle. Hair growth occurs at the base of the follicle, where cells in the hair bulb are nourished by dermal blood vessels.

NAILS

⁃ The nails, located on the distal phalanges of fingers and toes, are hard, transparent plates of keratinized epidermal cells that grow from a root underneath the skin fold called the cuticle (Fig. 13-2). The nail body extends over the entire nailbed and has a pink tinge as a result of the rich blood supply under- neath. At the base of the nail is the lunula, a paler, crescent- shaped area. The nails protect the distal ends of the fingers and toes.

Pallor (loss of color)

⁃ is seen in arterial insufficiency, decreased blood supply, and anemia. Pallid tones vary from pale to ashen without underlying pink.

Cyanosis

⁃ may cause white skin to appear blue-tinged, especially in the perioral, nailbed, and conjunctival areas. Dark skin may appear blue, dull and lifeless in the same areas.

Jaundice

⁃ in light and dark-skinned people is characterized by yellow skin tones, from pale to pump- kin, particularly in the sclera, oral mucosa, palms, and soles.

Acanthosis nigricans (Fig. 13-4C)

⁃ is roughening and darkening of skin in localized areas, especially the posterior neck

THE HEAD

⁃ The framework of the head is the skull, which can be divided into two subsections: the cranium and the face (Fig. 14-1).

Cranium

⁃ The cranium houses and protects the brain and major sensory organs. It consists of eight bones:

• Frontal (1)

• Parietal (2)

• Temporal (2)

• Occipital (1)

• Ethmoid (1)

• Sphenoid (1)

In the adult client, the cranial bones are joined together by immovable sutures: the sagittal, coronal, squamosal, and lambdoid sutures.

Face

⁃ Facial bones give shape to the face. The face consists of 14 bones:

• Maxilla (2)

• Zygomatic (cheek) (2)

• Inferior conchae (2)

• Nasal (2)

• Lacrimal (2)

THE NECK

⁃ The structure of the neck is composed of muscles, ligaments, and the cervical vertebrae (Fig. 14-2). Contained within the neck are the hyoid bone, several major blood vessels, the lar- ynx, trachea, and the thyroid gland, which is in the anterior triangle of the neck.

Muscles and Cervical Vertebrae

⁃ The sternomastoid (sternocleidomastoid) and trapezius mus- cles are two of the paired muscles that allow movement and provide support to the head and neck (Fig. 14-3). The ster- nomastoid muscle rotates and flexes the head, whereas the trapezius muscle extends the head and moves the shoulders.

Blood Vessels

⁃ The internal jugular veins and carotid arteries are located bilaterally, parallel and anterior to the sternomastoid muscles. The external jugular vein lies diagonally over the surface of these muscles.

Thyroid Gland

⁃ The thyroid gland is the largest endocrine gland in the body. It produces thyroid hormones that increase the metabolic rate of most body cells.