Integumentary System
Integumentary System
Integumentary System
• Stratum Basale: the deepest epidermal layer, attached to dermis along a wavy borderline.
• Stratum Spinosum: several cell layers thick, contains web-like cells called intermediate
filaments
• Stratum Granulosum: consists of three to five cell layers in which drastic change in
keratinocyte appear
• Stratum Lucidum: consists of few rows of clear, flat, and dead keratinocytes, appear as a
translucent band above the Stratum Granulosum
• Stratum Corneum: a broad zone of 20-30 layers thick which accounts for ¾ of the
epidermal skin
Cells in Epidermis:
• Melanocytes: the spider shaped epithelial cells that synthesize the pigment, melanin
• Langerhans: arise from bone marrow and migrate to epidermis
• Merkel Cells: present in the dermal-epidermal junctions, shaped like a spiky hemisphere
• Thick skin: covers the palms, fingertips, and soles of the feet, consisting of five layers
• Thin skin: covers the rest of body, the stratum lucidum is absent and other strata are
thinner
Epidermis:
Dermis:
• Second major skin region, is strong, flexible connective tissue. It cells are usually those
found in any connective tissue: fibroblasts, macrophages, and occasional mast cells. Its
semi-fluid matrix is heavily embedded with collagen, elastin and reticular fibers.
Skin Color:
There are three factors that contribute to skin color: Melanin, Carotene, and Hemoglobin,
but only Melanin is made in the skin.
• Melanin, a polymer made of tyrosine amino acids, ranges in color from yellow to
reddish-brown to black. Its synthesis depends on an enzyme in melanocytes called
tyrosinase, which passes from melanocytes to basal keratinocytes
Glands in Skin:
• Eccrine Glands: are far more abundant on the palms, soles and forehead. Each is a
tubular, coiled tubular gland.
• Apocrine Glands: are largely confined to axillary and anogenital areas. Larger than
Eccrine glands and their ducts empty into hair follicles.
• Ceruminous Glands: are modified apocrine glands found in the lining of the external ear
canal.
• Sebaceous Glands (Oil glands): are simple alveolar glands with little or no visible lumen
that are found all over the body except on the palms and soles. Secrete an oily secretion
called, sebum
• Basal Cell Carcinoma: is the least malignant and most common skin cancer. Occurs most
often on sun-exposed areas of the face and appear as shiny, dome-shaped nodules
• Squamous Cell Carcinoma: arises from the keratinocytes of the Stratum Spinosum.
Appears as a scaly reddened papule that appears on the head and hands
• Melanoma: cancer of melanocytes, the most dangerous type of skin cancer. Appear
spontaneously
Types of Burns:
• First-degree burn: only the epidermis is damaged. Symptoms are localized redness, pain
and swelling.
• Second-degree burn: injure the epidermis and the upper region of dermis. Symptoms
same as first-degree but blisters may appear
• Third-degree burn: involve the entire thickness of the skin. Burned area appears gray-
white, cherry red, or blackened and with little or no edema.
Rule of Nines:
• A method of estimating the extent of body surface that has been burned in an adult,
dividing the body into sections of 9 per cent or multiples of 9 per cent.