Integumentary System Flashcards
What is the most common cell type in the epidermis of the skin?
Where do the stem cells for this cell type come from?
- keratinocytes
- stratum basale layer
What are the structures of the integumentary system?
skin, hair, nails, oil (sebaceous) gland, and sweat (sudoriferous) glands
What are the 3 layers of the skin (from most superficial to least)?
- epidermis
- dermis
- hypodermis (SubQ)
The epidermis is composed entirely of what?
epithalial cells- stratified squamous + basal cell layer
also contains free nerve endings
There are ____ blood vessels in the epidermis
NO
What are the 5 layers of the epidermis?
- Come- Stratum Corneum
- Lets- Straum Lucidum
- Get- Straum Granulosum
- Sun- Stratum Spinosum
- Burned- Stratum Basale
Stratum Corneum
“top layer”
* DEAD keratinocytes that help prevent microbes from entering and also prevent dehydration
Stratum Lucidum
“clear layer”
* colorless protein eleidin that is rich in lipids and functions as a water barrier
* found in the palms, soles, and digits
Stratum Granulosum
“thin layer”
* granular layer (grainy appearance)
Stratum spinosum
“spiny layer”
* THICCest layer, keratinocytes, immune dendritic cells (Langerhan cells)- APC macrophages, sensory cells
Stratum Basale
“basal layer”
* bottom layer that has melanocytes that make pigment aka melanin, undergoes mitosis (stimulated by nerves) to make more skin cells (keratinocytes), and has Merkel cells that sense light touch
What is the squamous cell layer of the epidermis made of?
All the layers EXCEPT the stratum basale layer.
straum basale layer makes up basal cell layer
Which epidermal layer contains the melanocytes?
stratum basale.
The dermis contains mostly what type of tissue?
What are the two layers?
- connective tissue
- 2 layers: papillary- loose areolar CT = wrinkles = form fingerprints and give us our grip; reticular - THICC dense irregular CT
What is found in the dermis layer of the skin?
- blood vessels (capillaries) that carry heat to the skin surface and lymph vessels
- sensory receptors: corpuscle that sense touch (meisner) and pressure (pacinian)
- hair follicles
- sebaceous glands
- sweat glands
- elastin and collagen fibers that are made by fibroblasts
- arrector pilli smooth m.
- macrophages and mast cells
What are the components of the hypodermis aka SubQ tissue
- adipose tissue that cushions and insulates the body and plumps the skin
- blood vessels
What is the function of collagen of the skin?
resist tearing and skin and gives the smoothness of skin and strength and structure
- What type of muscle is the arrector pilli muscle?
- What layer is that m. found at?
- smooth
- dermis layer
What parts of the dermis are under sympathetic control?
- sweat glands
- arterioles- epi and nor epi binding to alpha 1 receptors causing constriction of vessels (sympathetics can also cause dilation when epi or norepi bind to beta 2 receptors if it’s way too hot)
- arrector pilli muscle- contracts and causes hair to stand up and that’s why we see goosebumps and contraction also generates heat
- What type of macromolecule is keratin? what is the function of keratin?
- Where is it found on the body?
- What type of cells make it?
- a fibrous protein that gives the epidermis its durability and protect’s the skin from physical damage
- throughout the epidermis and also in the hair and nails
- keratinocytes found throughout the epidermis
- What is the function of melanin?
- Where is it found?
- What cells make it?
- a protective umbrella over the nuclei of the cells in the deeper epidermal layers; absorbs UV light and so protects DNA from damage and also gives pigmentation/ color to hair, skin, and iris
- in the stratum basale
- melanocytes
What is the function of the integumentary system?
- protection (protect body from pathogen infection, injury, drying out, UV radiation)- unbroken skin is the #1 physical barrier
- regulation of body temperature
- excretions: water, salts, and minerals [Na, Cl, Mg], urea, and excrete stress (tears and sweat that contain cortisol) through EXOCRINE glands, which secrete items into ducts
- produce vitamin D from cholesterol in skin vessles when UV light hits the skin
- nerve endings and sensory receptors in the skin can detect pain, temp, pressure, and touch [free nerve endings sensing pain and temp in epidermis and touch, pressure/vibration receptors in dermis]
What are the EXOCRINE glands?
- sweat (sudoriferous) - eccrine and apocrine (special type of apocrine = ceruminous)
- oil (sebaceous)
Thermoregulation
* What is the HYPERthermia response?
* What is the HYPOthermia response?
- HYPERthermia: cool the body by: **increasing sweating **to do evaporative cooling; DILATION of skin blood vessles to be able to carry more **heat to the surface **of the skin and release the heat and cools blood down = heat dissipation.
- HYPOthermia: warm the body and keep the core warm by: decrease sweating; CONSTRICTION of skin blood vessles = loose less heat thru dissipation of heat to skin surface bc dec blood to skin surface and allows diversion of blood that is supplying skin to go to heart and skeletal m. = retain heat. ; skeletal m. and arrector pilli of dermis contraction also generates heat.
- What do the sweat glands contain?
- What are the two types of sweat glands?
- trace amounts of urea, lactic acid, and alcohol
- eccrine and apocrine
Eccrine Gland
* Where is it found?
* What type of sln does it secrete?
* When does it secrete those substances?
What type of gland is it?
- found throughout the body (NOT connected to hair follicle)- ie. forehead, neck, back
- salty sln of electrolytes and H2O (ODORLESS)- salt, KHCO3, glucose, antimicrobial peptides
- activated by high body temperature aka invovled in thermoregulation
A sweat aka sudoriferous gland
Apocrine Gland
* Where is it found?
* What type of sln does it secrete?
* When does it secrete those substances?
- found in armpits, groin, palms, and soles of the feet
- oily sln of fatty acid, triglycerides, and proteins [body odor comes from bacteria feeding on apocrine sweat]
- secretes sweat during stress or anxiety
Oil gland
* What does it secrete?
* What type of gland is it?
* connection hint
- secretes sebum, which is an oily mixture of lipids and porteins; waterproofs the skin, protects skin from pathogens
- holocrine gland
- connected to hair follicle and secretes sebum through the hair pore to lubricate and protect hair
Which gland IS connected to hair follicles?
oil (sebaceous) glands
Which sweat gland secretes odor filled sln and which secretes an ODORLESS sln
- odor: apocrine; only bc bacteria feeding on apocrine sweat
- odorless: eccrine
Which sweat glands starts secretion when its really hot?
ecrrine sweat gland
Which sweat gland secretes stuff when stressed and anxious?
- aprocine sweat gland
Which gland is invovled in thermoregulation?
eccrine sweat gland
other players: blood vessels and skeletal m.
- What is active Vit D required for?
- What is a major stimulator of production of ACTIVE Vit D (BUT IS NOT REQUIRED)? Where is ACTIVE Vit D produced?
- What are the other functions of Vit D?
- any sort of Ca absorption from diet from small intestines, so indirectly is needed for good bone health [ if eat lots of Ca and have no Vit D = Ca will not be taken up]
- PTH ; kidneys
- Ca reabsorption from kidneys, inc bone mineralization (deposit Ca and other minerals onto bone, decreases depression, decreases cancer risk, decreases allergies, decreases autoimmune dz’s, better heart health
When its too hot, the skin blood vessels will [_____] to cool the body down.
dilate
When the body is cold, the skin blood vessels will [____] to conserve heat
constrict
epi or norepi binding to alpha 1 adrenergic receptors of skin blood vessels
Ceruminous Glands
- modified apocrine glands
- accessory structures that produce ear wax
- found in the dermis of the ear canal
What cell type contributes to the waterproof properties of the outer layer of the skin?
keratinocytes!!!!!
