Gastrointestinal Motility and Smooth Muscle Early in life, children notice that strange gurgling sounds sporadically emanate from their "stomachs," particularly in periods between meals. This simple observation reflects the fact that the digestive tube is quite muscular and that muscle contractions and motility are integral parts of digestive function.
Tunica media is made up of smooth muscle cells and elastic tissue. It lies between the tunica intima on the inside and the tunica externa on the outside. The middle coat (tunica media) is distinguished from the inner (tunica intima) by its color and by the transverse arrangement of its fibers.
The iris sphincter muscle (pupillary sphincter, pupillary constrictor, circular muscle of iris, circular fibers) is a muscle in the part of the eye called the iris. It encircles the pupil of the iris, appropriate to its function as a constrictor of the pupil.
In cetaceans the prostate gland is surrounded by a very powerful compressor muscle. The prostate gland originates with tissues in the urethral wall. This means the urethra, a compressible tube used for urination, runs through the middle of the prostate. This leads to an evolutionary design fault for some mammals, including human males.
Vascular smooth muscle refers to the particular type of smooth muscle found within, and composing the majority of the wall of blood vessels. Nerve supply. Vascular smooth muscle is innervated primarily by the sympathetic nervous system through adrenergic receptors (adrenoceptors).