Integumentary
Functions:
The function of the Integumentary system is to protect the external
surface of the body. It protects the body against mechanical injury and
attack by bacteria, fungi, viruses, and parasites. It also keeps the body�s
temperature in various ways.
Major parts and organs:
The major parts and organs of the Integumentary system are the skin,
the epidermis, the dermis, sweat glands, nails, and hair. The skin covers
the whole body. It merges, without break, at the various body openings, with
mucous membranes of the alimentary and other canals. It forms a protective
barrier against the action of physical, chemical, and bacterial agents. Deep in
the skin, there are special end organs for the various sensations commonly
grouped as the sense of touch. The skin has two main layers; the epidermis,
or cuticle, is the outer layer, and the corium, or dermis, is the inner layer.
The epidermis is several cells thick, and has an external, horny layer of dead
cells that is constantly shed from the surface and is replaced from below by a
basal layer of cells. The dermis is extremely irregular, and consists of a
succession of papillae which are the smallest where the skin is thin, and
longest in the skin of the palms and soles. The papillae are the basis of
fingerprint identification. The sweat glands are found on every part of the
body. They are sparse on the back, and numerous on the palms and soles.
Each gland consists of coiled tubules that are situated in the subcutaneous
tissue, and a duct that extends through the dermis and forms a convoluted
spiral through the epidermis. Sebaceous glands, sac-like glands that secrete
the sebum that lubricates and softens the skin, open into the hair follicles a
short distance below the surface of the epidermis. The nails are flattened,
horny, protective coverings on the upper surface of the outer segments of the
fingers and toes. The nails are made of dead cells containing the fibrous
protein keratin. Hair is the slender, threadlike outgrowths of the epidermis.
Individual hairs are composed chiefly of the horny scleroprotein known as
keratin and contain neither blood vessels nor nerves.
Interactions with other systems:
The Integumentary system interacts with the Muscular, Excretory,
and Nervous Systems. The muscles from the Muscular system in the face
contract to form your facial expressions. The Integumentary system helps
the Excretory system by excreting sweat through the skin. The Nervous
system lets the body know when more nails or hair is needed, and supplies
the skin with nerves so it can perceive outside sensations.
Diseases:
Some of the diseases of the integumentary system are Acne,
Athlete�s Foot, and Warts. Acne is an inflammatory disease of the
sebaceous follicles of the skin. Symptoms of acne are the follicles and
surrounding tissue become inflamed and blackheads appear. Large cysts
sometimes appear after manipulation or trauma to an otherwise uninflamed
blackhead. Severe acne can be treated by application of topical
clindamycin or erythromycin. Sunlight is also helpful. Athlete�s Foot is a
fungal infection of the skin of the foot caused by species of the genus
Trichophyton. Symptoms of Athlete�s Foot are a reddish eruption,
followed by cracks in the skin between the toes and a watery discharge,
accompanied by itching at all stages. Athlete�s Foot can be treated with
topical agents and good foot hygiene. Warts, also called verrucae, are
common, contagious, epithalial tumors caused by at least 60 types of
human papillomavirus. Symtoms of warts are sharply demarcated,
rough-surfaced, round or irregular, firm, and light gray, yellow, brown, or
gray-black nodules 2 to 10 mm in diameter. They appear most often on
sites subject to trauma (e.g. fingers, elbows, knees, face). Most common
warts disappear spontaneously within 2 years or with simple non-scarring
treatment of a solution containing 17% salicylic acid and 17% lactic acid
applied daily. Warts can also be frozen off by a physician using a solution
of liquid nitrogen.