1. General Functions of the Subcutaneous Layer
1.1. Better known as the Hypodermis
1.2. Also known as superficial fascia
1.3. Isolation
1.4. Fat storage
1.5. Loose connection to underlying tissues
1.5.1. Muscle(s)
2. Cell Types Located in the Epidermis
2.1. Keratinocytes
2.1.1. Filled with tough protein
2.1.1.1. Called keratin
2.2. Stem Cells
2.2.1. Only located in stratum basal
2.2.2. Reproduce into two things
2.2.2.1. Stem cells
2.2.2.2. Keratin
2.2.3. Differentiate
2.3. Melanocytes
2.3.1. Produces
2.3.2. Secretes
2.3.3. Responsible for producing melanin
2.3.3.1. It's what gives our skin color
2.3.3.1.1. More melanin means darker skin
2.3.3.1.2. Less melanin means lighter skin
2.4. Merkel Cells
2.4.1. Also known as tactile epithelial cells
2.4.2. Respond to touch
2.5. Dendritic Cells
2.5.1. Mobile
2.5.1.1. These cells move around to protect us
2.5.2. Immune system cell
2.5.3. Looking for "invaders" aka germs
3. Layers of the Epidermis and Special Features and Functions
3.1. Stratum Basale
3.1.1. Primarily stem cells
3.2. Stratum Spinosum
3.2.1. Has spines between cells
3.2.2. Cells are being held together by desmosomes
3.2.2.1. Desmosomes give the spiny appearence
3.3. Stratum Granulosum
3.3.1. Darkest layer
3.3.2. Granules in the cell that produce and secrete a glycolipid
3.3.2.1. Waterproofing agent for the skin
3.4. Stratum Lucidum
3.4.1. Found only in thick skin
3.4.1.1. Palms of hands
3.4.1.2. Souls of feet
3.5. Stratum Corneum
3.5.1. Has keratinocytes
3.5.1.1. All dead
3.5.1.2. That's why it doesn't hurt when you get a hair cut
4. Components of the Integumentary System
4.1. Skin
4.1.1. Has multiple layers
4.1.1.1. Epidermis
4.1.1.1.1. Superficial region
4.1.1.1.2. Made of thick epithelial tissue
4.1.1.1.3. Keratinized stratified squamous epithelium
4.1.1.1.4. Contains 4 types of cells
4.1.1.1.5. The root word epi- means "over" or "above"
4.1.1.2. Hypodermis
4.1.1.2.1. Not technically apart of the integumentary system
4.1.1.2.2. Shares some of the skins functions
4.1.1.3. Dermis
4.1.1.3.1. Deep to the epidermis
4.1.1.3.2. A fibrous connective tissue
4.1.1.3.3. There are 4 cells to the dermis
4.1.1.3.4. Dermis binds the entire body together
4.1.1.3.5. Has two regions
4.1.1.3.6. The root word derm- means "skin"
4.1.2. Largest organ
4.1.2.1. Accounts for 7% of our body weight
4.2. Nails
4.2.1. Scalelike modification of the epidermis
4.2.2. Dead cells filled with keratin
4.2.3. Function: protection of fingers and toes
4.3. Hair
4.3.1. The root of hair sits in a folicle
4.3.2. Dead cells filled with keratin
4.3.3. Shaft of the hair sits above the skin
4.3.4. Function:
4.3.4.1. Sense things that lightly touch our skin
4.3.4.2. Protection against UV radiation and cold
4.4. Sweat Glands
4.4.1. Two types of sweat glands
4.4.1.1. Eccrine sweat gland
4.4.1.1.1. Most abundant sweat gland
4.4.1.1.2. Composed of mostly water and some salt
4.4.1.1.3. Location: nearly everywhere
4.4.1.1.4. Function: evaporative cooling and temperature control
4.4.1.1.5. Type of secretion: merocrine
4.4.1.2. Apocrine sweat gland
4.4.1.2.1. Produces a secretion that includes:
4.4.1.2.2. This type of secretion leads to body odor
4.4.1.2.3. Location: genitalia, axillary and anal regions
4.4.1.2.4. Function: sexual signaling
4.5. Sebaceous Gland
4.5.1. Are the skins oil glands
4.5.2. Location: everywhere EXCEPT the palms and soles
4.5.3. Oily product is called sebum
4.5.4. Function: to soften skin and collect dirt
4.5.5. Type of secretion: holocrine
5. General Functions of the Integumentary System
5.1. Protection
5.1.1. Barrier- Waterproof
5.1.2. UV Radiation
5.2. Temperature Regulation
5.2.1. Also called thermoregulation
5.2.2. Two important parts of temperature regulation
5.2.2.1. Blood Vessels
5.2.2.1.1. Increase or decrease blood flow where needed
5.2.2.2. Sweat Glands
5.2.2.2.1. Evaporation to cool us
5.3. Excretion
5.3.1. Water
5.3.2. Salt
5.4. Production of Vitamin D
5.4.1. Needed to absorb calcium in digestive system
5.4.2. Bone
5.4.2.1. Teeth
5.4.2.2. Used to strengthen here
5.4.3. Muscle
5.4.3.1. Helps with the function of muscle