Integumentary system

line body passageways that open to the outside of the body. secrete mucus.

multicellular mucus glands in the mucous membranes, secrete the protective lubricating mucus.

protective, lubricating mucus, which consists of water, salts, and a sticky protein. Provides lubrication and helps trap invading microorganisms.

line some of the walls of the thoracic and abdominopelvic cavities and cover organs that lie within these cavities. secrete serous fluid.

acts as a protective lubricant

line the cavities of movable joints. secrete synovial fluid

helps reduce friction at the movable joints.

(skin) largest membrane. consists of two layers. epidermis and dermis. considered an organ.

protection, body temperature regulation, cutaneous sensation.

vitamin d synthesis. excretion.

tiny flakes of urea on the skin, seen on people with kidney disease.

consists of four or five sublayers depending on its location. It is "avascular (without blood supply) and has no nerve supply.

• 1. stratum corneum
• 2. stratum lucidum-only present on thick skin, palms of hands, soles of feet.
• 3. stratum granulosum
• 4. stratum spinosum
• 5. stratum basale

pigment, screens out ultraviolet rays from the sun that cn damage tissues.

produce keratin, a protein that hardens and waterproofs the skin.

produce melanin

tactile cells, occur deep in the epidermis. serve as receptors for the sense of touch.

second layer of the skin. provides strength, extensibility (the ability to strecth) and elasticity (the ability to return to its original form). consists of two layers.

thin outer layer of dermis.

thick layer of dermis, makes up 80% of the dermis.

fingerlike projections that protude into the dermis.

fingerprints

hair, nails, sudoriferous glands, sebaceous glands

sensory protection, filtration, and some protection

portion of the hair that is visible on the surface

portion of the hair that penetrates the skin

saclike invagination of the epidermis from which hair root developes.

base of the hair follicle

bottom of hair follicle located within the bulb.

muscle that is attached to the hair follicle. when it contracts produces goose bumps.

subcutaneous fat of the body

subcutaneous layer or superficial layer. consists mostly of adipose tissue. storage site of most body fat.provides thermal insulation, absorbs shocks from impacts.

secrete sebum, not found on the palms of the hands or soles of the feet.

oily substance, inhibits bacterial growth and helps prevent drying of the hair and skin.

keratinzed epithelial cells.

area of new growth, semilunar lighter region of the nail.

secrete sweat by exocytosis. four kinds.

occur under most skin surface and secrete a watery solution through pores which serves to cool the skin as it evaporates.

occur under skin surfaces of the armpits and pubic regions. begin at puberty. secrete solution in response to stress or sexual excitement. 2 kinds.

secrete cerumen (earwax) into external ear canal. helps to impede the entrance of foreign bodies.

produce milk

• basal cell carcinoma
• squamous cell carcinoma
• malignant melanoma

appears in over 30% of fair-skinned people. most common. least malginant.

possible locations: ears, forehead, nose

typicaly in the keratinized epidermal cells. it may metastasize. rarely fatal.

possible locations: lips, mouth, face, ears.

affects the pigment producing melanocytes. usually starts as small dark growth, gradually becomes larger and irregular in shape.

• surface area affected-less than 10%
• depth of tissue damage-epidermis, not destroyed
• major effects-mild swelling, reddening, pain. skin heals witout scarring.

• suface area-less than 15%, less than 10% for child
• depth-epidermis and part of dermis destroyed.
• major effects-red or mottled. blisters, swelling, wet surface due to plama loss. destroys sensitive nerve endings.

• surface-more than 20%
• depth-all layers of skin destroyed
• major effects-white charred appearance, severe loss of body fluids.

(cogenital leukoderma)-absence of pigment in the skin, hair and irises, may be partial or complete. people have a genetic lack of melanin from both parents.