Integumentary System Flashcards
Integumentary System
the skin and its accessory structures
Three layers of the skin
1) Epidermis 2) Dermis 3) Hypodermis
4 layers of epidermal “thin skin”
1) stratum basale 2) stratum spinosum 3) stratum granulosum 4) stratum corneum
Layer that qualifies epidermis as “thick skin”
stratum lucidum
Composed of keratinized, stratified squamous epithelium
Epidermis
Type of cell that manufactures and stores a specific protein; found in all layers except the SB
Keratinocyte
Intracellular fibrous protein that gives hair, nails, and skin their hardness and water-resistant properties
Keratin
Bottom layer of the epidermis. Cells in this layer bond to the dermis via intertwining collagen fibers, referred to as the basement membrane
Stratum Basale
Folds on the top of the dermis that increase the strength of the connection between the dermis and epidermis
Dermal Papilla
Cuboidal-shaped stem cell that all keratinocytes derive from
Basal Cell
SB cell that functions as a receptor and is responsible for stimulating sensory nerves that the brain perceives as touch. Common in hands and feet
Merkel Cell
SB cell that produces the pigment melanin
Melanocyte
Layer of the epidermis found between the stratum granulosum and stratum basale. Joined by demosomes and made of 8-10 layers of keratinocytes formed in ther SB
Stratum Spinosum
Epidermal layer between the SS and SL. Generates keratin and keratohyalin, which gives the layer its grainy appearance
Stratum Granulosum
Epidermal layer between the SG and SC that is only found on the palms, fingers, and soles. It is packed with a lipid-rich protein called eleiden
Stratum Lucidum
Epidermal layer exposed to the outside environment. This dry, dead layer helps prevent the penetration of microbes and the dehydration of underlying tissues, and provides a mechanical protection against abrasion for the more delicate, underlying layers.
Stratum Corneum
Middle skin layer that contains blood and lymph vessels, nerves, and other structures, such as hair follicles and sweat glands. It is made of two layers of connective tissue that compose an interconnected mesh of elastin and collagenous fibers
Dermis
Two layers of connective tissue of the Dermis
Papillary Layer, Reticular Layer
Dermis layer made of loose, areolar connective tissue. Projects into the SB to form Dermal Papilla. Also has fibroblasts, adipocytes, small blood vessels, and phagocytes
Papillary Layer
Dermis layer made of dense, irregular connective tissue. Well vascularized and has a rich sensory and sympathetic nerve supply
Reticular Layer
Skin layer directly below the dermis and servesto connect the skin to the underlying fascia (fibrous tissue) of the bones and mus
Hypodermis
Fiber that provides structure
Collagen Fiber
Fiber that provides flexibility
Elastin Fiber
Accessory Structures of the Skin
Hair, nails, sweat glands, and sebaceous glands
Keratinous filament growing out of the epidermis
Hair
Smooth muscle that contracts in response to nerve signals from the sympathetic nervous system
Arrector Pili
3 phases of hair growth
1) Anagen Phase 2) Catagen Phase 3) Telogen Phase
Lasts 2-7 years. Cells divide rapidly at the root of the hair, pushing the hair shaft up and out
Anagen Phase
Lasts only 2 to 3 weeks, and marks a transition from the hair follicle’s active growth
Catagen Phase
The hair follicle is at rest and no new growth occurs. At the end of this phase, which lasts about 2 to 4 months, another anagen phase b
Telogen Phase
Produce sweat to cool the body. 2 types
Sudoriferous glands
Produces a hypotonic sweat for thermoregulation. Common in palms, soles, and forehead
Eccrine sweat gland
Produce water, salts, and organic compounds (hence smell). Deepest in dermis and common in hairy areas.
Apocrine sweat gland
Oil gland that is found all over the body and helps to lubricate and waterproof the skin and hair. Most sebaceous glands are associated with hair follicles. They generate and excrete sebum
Sebaceous gland
mixture of lipids secreted onto the skin surface to lubricate dry SC layer
Sebum
4 Purposes of the Integumentary System
1) protection 2) thermoregulation 3) sensory function 4) vitamin D absorption
form of cancer that affects the stem cells undergoing mitosis in the SB of the epidermis. Usually caused by UV radiation.
Basal cell carcinoma
form of cancer that affects the keratinocytes of the SS and presents as lesions commonly found on the scalp, ears, and hands
Squamous cell carcinoma
form of cancer characterized by the uncontrolled growth of melanocytes, the pigment-producing cells in the epidermis
Melanoma
An allergic reaction that manifests as dry, itchy patches of skin that resemble rashes
Eczema
a skin disturbance that typically occurs on areas of the skin that are rich in sebaceous glands
Acne
collagen-rich skin formed after the process of wound healing
Scar
an overproduction of scar tissue because the process of collagen formation does not stop when the wound is healed
keloid
(also called decubitis ulcers) skin injury caused by constant, long-term, unrelieved pressure on certain body parts that are bony, reducing blood flow to the area and leading to necrosis
bed sores
