Skin
What struct. seperates the Stratum basale from the underlying dermis?
A basal lamina
There is a cell that exists in the epidermis that in and of itself senses warm and cool temperatures. NAME. THAT. CELL.
A keratinocyte.
About how much time does it take for a cell to get from the stratum germinativum (basale) to become the squames of the stratum corneum?
About 4 weeks.
Name at least 2 accessory structures that you should expect to find with a hair follicle?
An errector pili muscle along with at least one sebacous gland.
Hair pigment give color. In which part of the shaft is that given off?
At the base of the follicle.
This epidermal layer consists of a single layer of cuboidal (or low columnar cells) and are actively dividing keratinocyte precursors.
Basale (germinativum)
From deepest to most anterior, what are the layers of the epidermis?
Basale(germantivum), Spinosum, Granulosum, Lucidum, and Corneum
In which part of the hair follicle do cells differentiate? In which part do they die :(?
Differntiation occurs in the deepest part. Death occurs as they move closer to the surface (sad, but true)
From where are the epidermis and dermis dervied?
Epi--Ectoderm Dermis--mesoderm
What are the two general compartments of the skin?
Epidermis and dermis
T/F: No cell division occurs in the Strat. Spinosum.
False. Cells continue to divide into this layer.
T/F: The Stratum Spinosum is only a few layers thick.
False. It is several thick.
T/F: Since cells continue to divide in the Stratum Spinosum, the majority of keritanoctyes are still immature.
False. The keritanocytes are still pretty mature.
Merkel Cells are found where?
In the basal layer of the epidermis.
Where is a Meissner corpuscle typically found?
In the dermal papillae.
When would you find the stratum lucidum?
In thick skin.
Since the startum basale is the deepest layer it must attach to some structure. Name that structure and how it actually attaches.
It attaches to the basal lamina and it does so via hemidesmosomes.
What is a sebaceous gland?
It is a gland that produces an oil into the NECK of the hair follicle.
Where are Langerhans cells and melanocytes most commonly found.
Langerhans-Stratum Spinosum Melanocytes--Stratum Basale
Which organ is the LARGEST sensory organ?
Le peau.
Which macromolecule might one find in the stratum corneum along with the dead keritanocyes. Why might you find them there>
Lipids. To help with waterproofing.
What three other cells can also be found in the epidermis?
Merkel Cells, Langerhans cells, and Melanocytes
What are the function of the following cells? Merkel Cells, Langerhans Cells, and Melanocytes.
Merkel Cells--They are associated with the sense of light touch Langerhans Cells--Immune dendritic cells functioning to take up microbes and become antigen presenting cells. Melanocytes--Melanin producing cells
What is another term for the keritanocytes of the Stratum Spinosum? Why do they carry this name?
Prickle Cells. Because they represent sites of attachment
How could one differentiate between a secretory portion and a duct of a SWEAT GLAND?
Secretory: this is a coiled epithelium that will sometimes give off a stratified cuboidal appearance when in all reality it is NOT. Also, you shouldn't be too shocked if you see MYOCARDIAL CELLS, who help the secretory portion to contract the sweat into the duct. Duct: Two distinct layers of cuboidal epithelium (stratified Epi).
An arrector pili muscle is made up of _____(smooth/striated muscle).
Smooth (like a criminal)
Fill in the blank: SKIN function to mechanically ______________, creates a ________________ to microbes, waterproof, regulate _____________ & assists _____________.
So a bunch of answers could work. PROTECT BARRIER TEMPERATURE (through sweating and reulattion of blood flow) PERCEPTION.
In an H & E stain, which layers of the Epidermis stain dark?
Stratum Basale (germinativum), Stratum Spinosum, and Stratum Granulosum.
The granules of melanin produced the melanocytes are generally taken up by which layers of the skin?
Stratum Basale and Stratum Spinosum.
In which layer are keritanocyes now flat scales of keratin?
Stratum Corneum.
In which layers do melanocytes actually hang out?
Stratum basale (germivantium)
In which epidermal layer do cells begin programmed death?
Stratum granulosum.
Which skin appendage is found in thick skin (there is only 1)?
Sweat glands
What are dermal papillae? What characteristic feature do the make up on the surface of the skin?
The D.P. interdigitates with the EPIDERMAL ridges (which make up the characteristic fingerprint) at the dermal/epidermal junction.
In what layer would you find prickle cells?
The Stratum Spinosum
Where are 'skin appendages' derived from?
The epidermis
Which type of cell primarily makes up the epidermis?
The keratinocyte
Which event allows keritanocytes leads to the 5 layers of skin?
The maturation of the keritnocyte.
What is the difference between a Meissner and a Pacinian corpuscle?
The name....But really a Pacinian corpuscle is bigger. THey are both found in the dermal layer, HOWEVER, a Meissner corpuscle is found in the DERMAL PAPILLAE)
Skin appendages such as sweat glands, sebaceous glands, hair, and nails are found in thick or thin skin?
Thin
What is the function of a pacinian corpuscle? Where are they found?
To detect mechanical pressure. They are found deep in the reticular layer.
T/F: A hair follicle is an invagination of the epidermis.
True
T/F: Free nerve ending exist in moderately high concentrations at the epidermis.
True
T/F: Melanocytes are neural crest derived cells that migrate into the skin during early embryonic developemnt.
True.
T/F: The melanin produced by the melanocytes assist in blocking harmful UV rays.
True.
T/F: The stratum corneum keritanocyes are attached via desmosomes.
True.
How many dermal skin layers exist?
Two. Papillary (loose CT that nourish the Epideermis) & the reticular layer (mostly made up of dense irreg. CT and makes up bulk of the dermis).
Describe the stratum lucidum.
Very tightly packed DEAD cells that are mostly cell membrane and keratin.
Sweat glands have 2 portions. Can you name them?
Yes. Secretory and the Duct.
