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a tunic or coat; used in anatomic nomenclature to designate a membranous covering of an organ or a distinct layer of the wall of a hollow structure, as a blood vessel.
tunica adventi´tia the outer coat of various tubular structures.
tunica albugi´nea a dense white fibrous sheath that encloses a part or organ, such as the testicle or ovary.
tunica conjuncti´va the conjunctiva.
tunica dar´tos dartos.
tunica exter´na an outer coat, such as the fibroelastic coat of a blood vessel.
tunica inter´na an inner coat or layer.
tunica in´tima the innermost coat of a blood vessel; called also Bichat's tunic.
tunica me´dia the muscular middle coat of a blood vessel.
tunica muco´sa the mucous membrane lining of various tubular structures.
tunica muscula´ris the muscular coat or layer surrounding the tela submucosa in most portions of the digestive, respiratory, urinary, and genital tracts.
tunica pro´pria the proper coat or layer of a part, as distinguished from an investing membrane.
tunica sero´sa the membrane lining the external walls of the body cavities and reflected over the surfaces of protruding organs; it secretes a watery exudate.
tunica vagina´lis tes´tis the serous membrane covering the front and sides of the testis and epididymis.
tunica vasculo´sa a vascular coat, or a layer well supplied with blood vessels.
the muscular, usually middle, layer of a tubular structure; for most of the gastrointestinal tract, it consists of an outer longitudinal layer of muscle and an inner circular layer.
The smooth muscle layer in the walls of organs such as the bronchi, intestines, and blood vessels.
See also: tunica