stratum spinosum
Last reviewed 01/2018
The stratum spinosum is the epidermal skin layer deep to the stratum granulosum but superficial to the stratum basale. It is several cells in thickness.
Cells here are characterised by spinous surface processes which abutt similar regions on neigbouring cells. At this site, keratinocytes have cytoplasmic continuity via gap junctions and continuity of tonofilament cell cytoskeletons via desmosome junctions.
The cytoplasm contains abundant organelles e.g. nucleus, mitochondria and lamellar granules. The latter contain complex carbohydrates, lipids and proteins which are discharged into the extracellular space with ascent of the cell.