Chapter 1- Epidermis- Spinous Layer- Stratum spinosum Flashcards
stratum spinosum is in between which two layers?
basal layer and stratum granulosum
Stratum spinosum is composed of the daughter cells of which layer?
stratum basale
In haired skin, the spinous layer is how thick?
one or two cells
In what areas does the spinous layer become much thicker? How thick?
footpads, nasal planum, mucocutaneous junctions; 20 cell layers
Describe the color of the stratum spinosum cell layer? nucleated or not nucleated? what shape?
lightly basophilic to eospinophlic; nucleated; polyhedral to flattened cuboidal
The keratinocytes of the spinous layer are connected by what structures? These structures are more prominent in haired or nonhaired skin?
intercellular bridges (prickles); nonhaired skin
Keratinocyte adhesion is mediated by four major types of adhesive and communicative structures. Name them.
Desmosomes; hemidesmosomes; adherens junctions; focal adhesions
Hemidesmosomes and focal adhesions connect which structures? What are their locations?
Mediate adhesion of basal cells to the underlying extracellular matrix; located on the basal surface of basal cells
Desmosomes and adheres junctions connect which structures?
Mediate adhesion between keratinocytes in all epidermal layers
The keratinocyte cytoskeleton consists of three types of cytoplasmic filaments. Name them.
cytokeratin, actin, microtubules (tubulin)
Name the functions of the cytoplasmic filaments of keratinocytes
orientation, polarization, organelle sorting, motility, shape change, signal transduction, structural resilience of keratinocytes
Ultrastructurally, keratinocytes are characterized by keratin intermediate filaments (Cytokeratin, tonofilaments) and ____.
desmosomes
What substances are crucial for desmosome and hemidesmosome formation?
calcium and calmodulin
Keratinocytes are phagocytic. What do they phagocytose?
erythrocytes, melanin, melanosomes, cellular fragments, latex beads, inorganic substances
