The stratum spinosum (or spinous layer/prickle cell layer) is a layer of the
epidermis found between the
stratum granulosum and
stratum basale. This layer is composed of polyhedral
keratinocytes.
These are joined with
desmosomes.
Their spiny (Latin, spinosum) appearance is due to shrinking of the
microfilaments between desmosomes that occurs when stained with
H&E.
Keratinization begins in the stratum spinosum, although the actual keratinocytes begin in the
stratum basale.
They have large pale-staining nuclei as they are active in synthesizing fibrilar proteins, known as
cytokeratin, which build up within the cells aggregating together forming
tonofibrils. The tonofibrils go on to form the desmosomes, which allow for strong connections to form between adjacent keratinocytes. The stratum spinosum also contains
Langerhans cells.
Clinical significance
Diffuse
hyperplasia
Hyperplasia (from ancient Greek ὑπέρ ''huper'' 'over' + πλάσις ''plasis'' 'formation'), or hypergenesis, is an enlargement of an organ or tissue caused by an increase in the amount of organic tissue that results from cell proliferati ...
of the stratum spinosum is termed
acanthosis.
Additional images
Image:Normal Epidermis and Dermis with Intradermal Nevus 10x.JPG, Epidermis and dermis of human skin
Image:Skinlayers.png, Section of epidermis
See also
Spinous cell
Spinous cells, or prickle cells, are keratin producing epidermal cells owing their prickly appearance to their numerous intracellular connections. They make up the stratum spinosum (prickly layer) of the epidermis and provide a continuous net-lik ...
References
{{integumentary system
Skin anatomy
Epithelial cells