{{Short description|Layer of the epidermis}} thumb|Histologic image showing a section of epidermis. Stratum spinosum labeled slightly below center. The '''stratum spinosum''' (or '''spinous layer/prickle cell layer''')<ref>{{cite book |last1=Rook |first1=Arthur |last2=Burns |first2=Tony |title=Rook's textbook of dermatology. |date=2004 |publisher=Blackwell Science |isbn=978-0-632-06429-8 |pages=3.7–3.8 |oclc=55097298 }}</ref> is a layer of the epidermis found between the stratum granulosum and stratum basale.<ref>{{cite book |last1=James |first1=William D |last2=Berger |first2=Timothy G |last3=Elston |first3=Dirk M |last4=Odom |first4=Richard B |title=Andrews' diseases of the skin: clinical dermatology. |date=2006 |publisher=Saunders Elsevier |isbn=978-0-7216-2921-6 |page=2 |oclc=62736861 }}</ref> This layer is composed of polyhedral keratinocytes.<ref name=":0" /><ref name=":1" /> These are joined with desmosomes.<ref name=":0" /> 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,<ref>{{cite book |last1=Marks |first1=James G |last2=Lookingbill |first2=Donald P |title=Lookingbill and Marks' principles of dermatology |date=2006 |publisher=Saunders Elsevier |isbn=978-1-4160-3185-7 |page=6 |oclc=70829704 }}</ref> although the actual keratinocytes begin in the stratum basale.<ref name=":1" /> They have large pale-staining nuclei as they are active in synthesizing fibrillar 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, which functions as a macrophage by engulfing bacteria, foreign particles, and damaged cells that occur in this layer.<ref>{{cite book |last1=Young |first1=Barbara |last2=Heath |first2=John W |last3=Stevens |first3=Alan |last4=Lowe |first4=J S |last5=Wheater |first5=Paul R |last6=Burkitt |first6=H. George |title=Wheater's functional histology: a text and colour atlas |date=2000 |publisher=Churchill Livingstone |isbn=978-0-443-05612-3 |oclc=43051605 }}{{page needed|date=October 2021}}</ref><ref>{{cite book |doi=10.1016/b978-0-12-374279-7.15008-8 |chapter=Psoriasis, Cutaneous Lupus Erithematosus and Immunobiology of the Skin |title=Encyclopedia of Immunobiology |year=2016 |last1=Di Meglio |first1=Paola |last2=Conrad |first2=Curdin |pages=192–203 |isbn=978-0-08-092152-5 }}</ref><ref name="Openstax Anatomy & Physiology attribution">{{CC-notice|cc=by4|url=https://openstax.org/books/anatomy-and-physiology/pages/5-1-layers-of-the-skin}} {{cite book|last1=Betts|first1=J Gordon|last2=Desaix|first2=Peter|last3=Johnson|first3=Eddie|last4=Johnson|first4=Jody E|last5=Korol|first5=Oksana|last6=Kruse|first6=Dean|last7=Poe|first7=Brandon|last8=Wise|first8=James|last9=Womble|first9=Mark D|last10=Young|first10=Kelly A|title=Anatomy & Physiology|location=Houston|publisher=OpenStax CNX|isbn=978-1-947172-04-3|date=June 28, 2023|at=5.1 Layers of the skin}}</ref>
== Clinical significance == Diffuse hyperplasia of the stratum spinosum is termed acanthosis.{{Citation needed|date=November 2020}}
==Additional images== <gallery> Image:Normal Epidermis and Dermis with Intradermal Nevus 10x.JPG|Epidermis and dermis of human skin Image:Skinlayers.png|Section of epidermis </gallery>
==See also== * Spinous cell
==References== <references> <ref name=":1">{{cite book |doi=10.1016/b978-0-12-801238-3.99217-1 |chapter=Skin Microbiology |title=Reference Module in Biomedical Sciences |year=2016 |last1=McBain |first1=A.J. |last2=o'Neill |first2=C.A. |last3=Oates |first3=A. |isbn=978-0-12-801238-3 }}</ref> <ref name=":0">{{cite book |doi=10.1016/b978-0-12-386456-7.03501-2 |chapter=Skin: Basic Structure and Function |title=Pathobiology of Human Disease |year=2014 |last1=Barbieri |first1=J.S. |last2=Wanat |first2=K. |last3=Seykora |first3=J. |pages=1134–1144 |isbn=978-0-12-386457-4 }}</ref> </references>
{{integumentary system}}
Category:Skin anatomy Category:Epithelial cells