What is the function of the skin?
Maintains homeostasis by
Regulating temperature
Protecting underlying tissues
Slowing water loss
Housing sensory receptors
Synthesizing certain chemicals
Excreting wastes
What are the 2 layers of skin?
Epidermis & dermis
What is the subcutaneous layer?
A layer of adpiose tissue beneath the epidermis & dermis
What does the subcutaneous layer contain?
Made of fat, or adipose tissue
Nails consist of what type of cells?
Stratified squamous epithelial cells
What are the structures within the dermis?
Made of connective tissues
Papillary layer
Dermal papillae
Meissner’s corpuscle
Capillary net
Free-nerve endings
Dermal ridges
Reticular layer
Arrector pili muscle
Hair follicle
Sebaceous gland
Pacinian corpuscle
Sudoriferous gland
Dermal papillae
Zippers together the dermis & epidermis
Meissner’s corpuscle
Sensory receptors that sense light touch
Capillary net
Delivers blood to & from the top of the dermis
Free-nerve endings
Sensory receptors that sense pain, heat, & cold
Dermal ridges
Large mound of dermal papillae in the hands & feet
Arrector pili muscle
Contracts to cause a hair to raise on end
Hair follicle
Where a hair grows from
Sebaceous gland
Oil glands
Pacinian corpuscle
Sensory receptors that sense heavy pressure
Sudoriferous gland
Sweat glands
What are the layers of the epidermis?
Stratum
Corneum
Lucidum
Granulosum
Spinosum
Basale
What are the characteristics of each layer of the epidermis?
Made of epithelial tissues
Stratum corneum - most superficial layer; made of 20 to 30 layers of dead squamous cells; constantly shedding
Stratum lucidum - very thin; only found in thick skin; found in palms or soles; dead
Stratum granulosum - living cells
Stratum spinosum - living cells
Stratum basale - living cells; mitotic; deepest layer; pushing the more superficial layers up & causing them to shed off
Where are all of these structures located?
Epidermis
Free-nerve endings
Capillary net
Arrector pili muscle
Dermal papillae
Meissner’s corpuscles
Sudoriferous gland
Pacinian corpuscle
Vein
Artery
Hair follicle
Adipose tissue
Hypodermis
Reticular layer of the dermis
Sebaceous glands
Papillary layer of the dermis
Epidermis
Free-nerve endings
Capillary net
Arrector pili muscle
Dermal papillae
Meissner’s corpuscles
Sudoriferous gland
Pacinian corpuscle
Vein
Artery
Hair follicle
Adipose tissue
Hypodermis
Reticular layer of the dermis
Sebaceous glands
Papillary layer of the dermis
What does the body do to regulate temperature?
In response to increased body temperature, the skin can cool the body down by sweating or dilating blood vessels located in the dermis. The dilated vessels allow heat to be released & make you turn red when warm.
In response to lowered body temperature, the blood vessels constrict, preventing heat loss. Tiny muscles in the dermis can also pull hair upright in an attempt to trap heat near the skin surface, causing goosebumps. Free-nerve endings can activate muscles to shiver, generating heat.
What happens when there is inflammation of the skin?
Blood vessels dilate & become more permeable, causing tissues to become red & swollen.
Superficial cuts are filled in by reproducing epithelial cells.
Deeper cuts are closed off by clots, covered by scabs, & eventually filled in by fibroblasts, making connective tissue. Blood vessels extend into the area, injured tissues are replaced, & the scab falls off.
Large wounds leave scars, & healing may be accompanied by the formation of granulations.
Be able to describe the degrees of burns.
1st degree burns can usually be treated at home with cool water & aloe. The epidermis is the only level affected, & the wound is considered superficial. The skin becomes pink but doesn’t blister or scar, & no underlying tissues are damaged.
In 2nd degree burns, both the dermis & the epidermis are damaged. Skin will appear swollen, red, & shiny, or wet. Blisters will usually form on a 2nd degree burn.
3rd degree burns affect every layer of the skin, often completely destroying the epidermis & dermis. Often, these burns don’t hurt because the underlying nerve tissue has been destroyed as well. Skin will appear white, charred, & leathery.
What is used to assess burn patients?
The Rule of 9’s
What are the long-term effects of burn victims?
Contracture
Inability to sweat
Dry or even cracked skin
Discoloration
Sensation changes