Integumentary System Flashcards
(15 cards)
What are some of the facts and structures of the Integumentary System?
Facts:
The bodies outer layer
Skin weighs about 20 pounds
Another word for skin is integument
Structures:
Skin
Nails
Hair
Glands
Nerves
Blood vessels
What are the functions of the system?
Protection
Tough keratin (a tough protein found in skin, hair, and nails) protects against mechanical injury and chemical damage
Melanocytes are cells produce melanin to protect against UV ray damage
Acidic sweat protects against bacterial infections
Water Barrier
Keratin and oils in the skin reduce water loss through evaporation and form a barrier against water infusion
Temperature Regulation
Capillaries dilate to release heat and constrict to conserve heat. Sweat evaporation provides a cooling effect.
Continued…
Vitamin D production
Sunlight converts cholesterol into vitamin D, which is essential for bone health
Waste elimination
Urea and uric acid are eliminated in sweat
Sensory Perception
Receptor cells transmit information about touch, pressure, vibration, pain, and temperature to the central nervous system
What are the layers of the skin?
- Epidermis
- Dermis
- Hypodermis
What are the layers of the skin?
- Epidermis
- Dermis
- Hypodermis
What is a Epidermis?
The outer layer of the skin
Composed of stratified epithelial cells
The epidermis does not contain a blood supply
Contains merkel cells- touch receptors
Contains epidermal dendrive cells- cells that initiate other cells to fight off foreign invaders (Bacteria)
Layer responsible for skin color
Contains 5 layers of tissues (From superficial to deep)
What are the Epidermis Layers?
Stratum Corneum- dead cells filled with keratin and constantly shedding. Replacing itself every 25-45 days.
Stratum Lucidum- thick skin layer of dead cells only found on palms of hands, fingers, soles of feet, and toes
Stratum Granulosum- live Keratinocytes become flatter and flatter making them tough and water resistant
Stratum Spinosum- live keratinocytes become flatter and flatter making them tough and water resistant
Stratum Basale - absorbs nutrients from dermis and produces live skin cells
Come Lets Get Sun Burnt
Skin Color
Stratum Basale contains melanocytes that produce melanin
The amount of melanin produced is based on genetics
Exposure to sunlight causes melanocytes to produce more melanin
Melanin granules are pushed out into the neighboring skin cells, the result in tanning
Extra melanin in the skin functions as sunscreen by scatters and absorbs the UV rays before penetrating through the epidermis
Albinism- prevents the normal production of melanin resulting in little pigment in the skin, hair, and nails
What is the function and structure of Dermis?
Contains two layers
Papillary layer- (superficial layer) contains capillaries and sensory receptors and take on a rigid pattern responsible for your fingerprint called dermal papillae. Dermal papillae create a connection between the epidermis and dermis and form mounds on hands and feet called dermal ridges (your fingerprint)
- Every person has a different fingerprint or dermal ridge pattern
Reticular layer- (deep layer) includes blood and lymphatic vessels, sweat and oil glands, muscles, hair follicles, and nerve endings
Continued…
Composed of collagen and elastic fibers. Collagen fibers provide toughness and the elastic fibers keep skin looking young.
Contains hair follicles
Has a rich supply of blood vessels and sweat glands to regulate body temperature
Contains sensory receptors for touch, vibration, pain, and temperature
Meissner receptors- detect light touch
Pacinian corpuscle- detect deep pressure and vibrational changes
Free nerve endings- respond to pain, light touch, and temperature variations
Contains phagocytes for ingesting foreign bodies such as bacteria
What are Sudoriferous glands (Sweat Glands)
Distributed throughout the body with high concentration in under arms, palms and soles of feet, and the forehead
Sweat is odorless but when left on skin turns into an odor due to bacteria
Types of sweat glands: Eccrine and apocrine glands
Eccrine glands: cover most of the body. Sweat is clear that contains mostly water that opens directly onto the skin.
Apocrine glands: Located on genitals and armpits.
Secrete milky fluid that secrete onto the hair follicles.
Sweat glands are activated to produce sweat when temperatures rise and evaporation cooling reduces body temperature
What are Sebaceous Glands (Oil Glands)
Location
Located all over the body accept for palms of hands and soles of feet
Empty into hair follicles and directly on skin
Function
Produce oily substance called sebum
Keep skin and hair soft and kill bacteria
Hair Follicles
Structure
Bulb-shaped and with an arrector pili attached on either side
Hair color
Melanocytes in the follicle produce the pigment that gives hair its color. As a person ages, melanocytes produce less melanin turning hair gray or white
Hair texture
The shape of the hair follicle. A round follicle produces straight hair; a oval follicle produces wavy hair; and a flat-shaped follicle produces curly hair
Goosebumps
When cold or frightened the arrector pili muscles contract pulling the hair upright causing goosebumps. The erect hair traps a layer of air close to the skin, adding insulation to help warm the body
Nails
Structure
Nail bed: located underneath the nail
Nail matrix: the thickened hard part of the nail. Are clear but appear pink due to the blood supply under the nail bed. This is where the nail grows
Lunule: the crescent portion located on top but located towards the bottom of the nail matrix
Hypodermis
Made of adipose tissue
Source of energy
Padding and insulating the interior of the body
Connects skin to muscle
