Palaeonemertea may be para-or nerve cords are inside the body-wall longitudinal muscle, and " Tubulanus ", in which the nerve cords are between the outer circular muscle and the epidermis.
22.
Under the skin is a layer of nerve tissue, and two layers of muscles a thin outer layer of circular muscle, and a much thicker inner layer of longitudinal muscle.
23.
These are the internal anal sphincter and the external anal sphincter, which are circular muscles that normally maintain constriction of the orifice and which relaxes as required by normal physiological functioning.
24.
Peristalsis is the wormlike movement by which the alimentary canal or other tubular organs with both longitudinal and circular muscle fibers propel their contents, consisting of a wave of contraction passing along the tube.
25.
The tongue is protruded by contracting circular muscles that change the shape of the tongue and force it forwards and contracting two genioglossal muscles attached to the caudal end of the tongue and to the mandible.
26.
The group includes genera such as " Cephalothrix " in which the nerve cords are inside the body-wall longitudinal muscle, and " Tubulanus ", in which the nerve cords are between the outer circular muscle and the epidermis.
27.
Extension is driven by an increase in internal fluid pressure, which species with flexible exoskeletons produce by contracting circular muscles that lie just inside the body wall, while species with a membranous sac use circular muscles to squeeze this.
28.
Extension is driven by an increase in internal fluid pressure, which species with flexible exoskeletons produce by contracting circular muscles that lie just inside the body wall, while species with a membranous sac use circular muscles to squeeze this.
29.
If you're young, you may never have heard of GERD because your lower esophageal sphincter, a circular muscle that opens to let food pass into the stomach then closes again, is doing a fine job of keeping food where it belongs, in your stomach.
30.
:: He means sphincter : specifically, the urethral sphincter . ( A sphincter is any circular muscle ( or group of muscles ) that contracts to regulate the flow of material through an opening ) . talk ) 18 : 14, 7 October 2006 ( UTC)
