Flashcards in Lecture 7- Integument Deck (69)
A 44 year old female is told that she has skin cancer. Some type of carcinoma! This would be cancer of what part of the skin?
What is the outermost epithelial layer?
What is the layer of connective tissue under the epidermis?
What is the layer of connective tissue under the dermis?
Where are keratinocytes found?
In the dead and alive tissue of the stratified squamous epithelial cells.
As basal cells divide, they move toward which surface?
the apical surface to slough off
Does the thickness of the epidermal layer change?
no, it is a very orderly process
What are melanocytes?
Dendritic processes that make melanin. Found in the basement membrane.
What are Langerhans cells
Dendritic processes that are immune cells
Where are Tacticle (Merkel) cells found?
In the basement membrane connecting to a sensory nerve ending
There is thick skin and think skin. How do they differ?
The epidermis is thicker in thicker in skin
What characterizes the stratum basale? (5)
- one cell layer thick
- cuboidal or columnar cells
- contains hemidesmosomes
- mitotic cells
- contains desmosomes
What characterizes the stratum spinosum? (5)
- does not contain hemidesmosomes
- contains desmosomes
- has some mitotic cells
- thicker in thick skin than in thin skin
- Active cells
How are tonofibrils formed?
Keritanocytes in the stratum spinosum produce keratin that forms the intermediate filaments or tonofibrils in the epidermis.
Intermediate filaments are involved in intercellular adhesion. Is this via adherent junctions, desmosomes, or tight junctions?
How would you describe the nuclei in keratinocytes in the stratum spinosum?
Euchromatic nucleus producing a lot of protein
Describe the outer cell body of the stratum spinosum.
prickly or spiny
What characterizes the stratum granulosum? (4)
- Only 3-5 layers of cells
- Cells develop a lipid envelope
- Cytoplasm has basophilic masses
How does profilaggrin stain?
intensely blue has a lot of phosphate groups that are very acidic, basophilic and stain blue. Exception to proteins staining pink*
Where are the lamellar granules produced and what is their function?
Lipids produced in the cells and are exocytosed to form a layer around the plasma membrane to act as part of the water barrier of skin
What is the purpose of filaggrin?
Fillagrin brings keratin and tonofilaments together to condense them.
What is keratinization?
The process of binding keratin to filaggrin
What characterizes the stratum lucidum? (3)
- see only in thick skin
- cells have lost their nuclei and organelles
- have desmosomes
How thick is stratum lucidum?
only a couple cell layers
What is the stratum corneum?
Nonnucleated, keratinized cells called squames or cornified cells that have lost their desmosomes and will slough off
Having fair skin increases your risk of skin cancer because there is:
Less melanin in keratinocytes
How do melanocytes stain?
Stains much clearer around the nucleus than other basal cell layers
How do melanocytes orient themselves in the keratinocyte?
In the supranuclear cap to protect DNA from UV radiation
Where are Langerhans cells and how do they stain?
Stratum spinosum and stain brown