Integumentary System Flashcards
Integumentary System
Encloses internal body structures; site of many sensory receptors; thermoregulation; vitamin D synthesis
Main Organs: Hair, Skin, Nails
Function #1- Protection
The skin protects the rest of the body from the basic elements of nature such as wind, water, and UV sunlight.
Function #2- Sensory Function
The skin acts as a sense organ because the epidermis, dermis, and the hypodermis contain specialized sensory nerve structures that detect touch, surface temperature, and pain.
Function #3- Thermoregulation
The sympathetic nervous system is continuously monitoring body temperature and initiating appropriate motor responses.
Function #4- Vitamin D Synthesis
The epidermal layer of human skin synthesizes vitamin D when exposed to UV radiation. In the presence of sunlight, a form of vitamin D3 called cholecalciferol is synthesized in the skin. Vitamin D is essential for normal absorption of calcium and phosphorous, which are required for healthy bones.
Skin
The skin is made of multiple layers of cells and tissues, which are held to underlying structures by connective tissue.
Epidermis
Most superficial
Dermis
Middle layer
Hypodermis
Deepest layer
Keratinocyte
a cell that manufactures and stores the protein keratin.
Stratum basale
Deepest epidermal layer (the base) and attaches the epidermis to the basal lamina, below which lie the layers of the dermis.
Stratum spinosum
The desmosomes interlock with each other and strengthen the bond between the cells.
Stratum granulosum
Has a grainy appearance due to further changes to the keratinocytes as they are pushed from the stratum spinosum.
Stratum lucidum
This thin layer of cells is found only in the thick skin of the palms, soles, and digits. The keratinocytes that compose the stratum lucidum are dead and flattened
Stratum corneum
The increased keratinization (also called cornification) of the cells in this layer gives it its name, usually 15 to 30 layers of cells in the stratum corneum.
From Superficial to Deep
Come-stratum corneum Let’s-stratum lucidum Get- stratum granulosum Sun- stratum spinosum Burnt- stratum basale
Thick Skin
All layers of skin, only found on palms of hands and soles of feet
Thin Skin
Layers 1,3, 4 and 5- stratum corneum, stratum granulosum, stratum spinosum, stratum basale
Keratin
an intracellular fibrous protein that gives hair, nails, and skin their hardness and water-resistant property
Hair
Keratinous filament growing out of the epidermis. It is primarily made of dead, keratinized cells
Hair Follicle
Strands of hair originate in an epidermal penetration of the dermis
Hair Shaft
The part of the hair not anchored to the follicle, and much of this is exposed at the skin’s surface
Hair Root
The rest of the hair, which is anchored in the follicle that lies below the surface of the skin
Free Edge
Ensures nail bed is covered and protected
