Lab Chapter 9: Integumentary System Flashcards
Rule of Nines
Quick method of estimating the percent of body surface area affected by burns. Each major area represents 9% of the total body surface area
First Degree Burn
- Only surface of epidermis is damaged
- Redness results from inflammation of damaged tissues
- Healing occurs within one week
- No scarring occurs
- e.g. sunburn
Second Degree Burn
- Epidermis & often part of dermis is damaged
- accessory structures (hair, gland, etc.) are intact
- blistering, pain and swelling occur
- healing occurs from accessory structures & edge of burn
- healing occurs in 2 weeks (epidermis only) up to 2 months (dermis involved)
- some scarring may occur
Third Degree Burn
- Epidermis & dermis destroyed; hypodermis & tissues beneath damaged
- usually painless due to nerve destruction
- accessory structures and blood vessels destroyed; healing cannot occur
- skin grafting is usually required
- infections likely and life-threatening
Basal Cell Carcinoma
- most common type
- origin: Stratum basale
- rarely metastasizes
- small, shiny bump on skin surface; as bump enlarges, often develops a central depression and beaded “pearly” edge
- least dangerous
Squamous Cell Carcinoma
- Origin: stratum spinosum
- can metastasize to lymph nodes if untreated
- lesions are raised, reddened, and scaly; usually appear on scalp, ears, lower lip, or back of the hand
Malignant Melanoma
- most deadly type of skin cancer
- origin: often arises from the melanocytes of a pre-existing mole
- metastasizes very quickly & drug resistant
- early detection is crucial for survival
ABC Rule
A for Asymmetry: irregular in shape
B for Border: borders are unclear or irregular
C for Color: generally mottled with many colors
D for Diameter: growths greater than 5mm in diameter
E for Elevation: raised above the skin surface
Stratum Corneum
outermost layer of both thick and thin skin; consists of 15 to 30 layers of dead, keratinized cells; protects the underlying cells and helps to minimize water loss from body
Stratum Lucidum
translucent layer immediately deep to s. corneum; found in thick skin only
Stratum Granulosum
Deep to s. lucidum in thick skin (s. corneum in thin skin); three to five cell layers thick; keratin formation begins in this layer and cells begin to die
Stratum Spinosum
Thicker layer just deep to s. granulosum; cells in this layer shrink during histological preparation, giving them characteristic “spiny” look that lends this layer its name
Stratum Basale (germinativum)
deepest layer of epidermis; single layer of cells located adjacent to dermis; mitotically active, rapidly replacing cells of stratum corneum that are constantly being shed
Epidermis
composed mostly of keratinized stratified squamous epithelium and forms the outermost protective shield of the body; composed of several strata (5 in thick skin & 4 in thin skin)
Dermis (corium)
composed mainly of connective tissue; located under epidermis
Papillary layer
Most superficial portion of the dermis; consists of loose connective tissue, tiny blood vessels and some somatosensory receptors
Tactile Corpuscles
receptors for touch; most numerous in sensitive areas of the skin (lips, fingertips & eyelids)
Dermal papillae
Projections of dermal tissue that extend upwards into the epidermis; increases the surface area for better attachment of the dermis to the epidermis
Reticular layer
found beneath papillary layer; consists of dense irregular connective tissue, with numerous somatosensory receptors, nerve fibers, and blood and lymphatic vessels
Lamellated Corpuscle
deep pressure and vibration receptors found in the dermis and hypodermis of the skin and other organs
Hypodermis
Superficial fascia; subcutaneous layer; lies deeps to the reticular layer of the dermis; composed primarily of adipose tissue and loose connective tissue; connects skin to underlying tissues, acts as an insulator, serves as fat storage depot
Sudoriferous (sweat) glands
produce a watery secretion that helps cool the body via evaporative heat loss; two types eccrine and apocrine
Eccrine (merocrine) sweat glands
numerous in skin of hands, feet, forehead; ducts pass to surface of skin
Apocrine sweat glands
found in axillary and anogenital regions; secrete their product into hair follicles; secretions contain proteins and fatty substances that contribute to body odor when digested by bacteria
Hair
projects above the skin surface in most place of the body; composed of keratin
Arrector Pili Muscle
causes hair to stand in animals and goose bumps in humans
Sebaceous glands
associated with hair that secrete an oily substance called sebum into follicle
Nails
located on the dorsal surface of the distal ends of the fingers and toes
