plicae circulares

(noun)

The circular folds (valves of Kerckring) (also, plicae circulares / valvulae conniventes) are large valvular flaps projecting into the lumen of the bowel.

Related Terms

Examples of plicae circulares in the following topics:

  • Absorption in the Small Intestine

    • Structurally, the mucosa is covered in wrinkles or folds called plicae circulares, considered permanent features in the wall of the organ.
    • From the plicae circulares project microscopic finger-like pieces of tissue called villi (Latin for "shaggy hair") .
    • The function of the plicae circulares, the villi and the microvilli is to increase the amount of surface area available for the absorption of nutrients.

  • Anatomy of the Digestive System

    • It contains the plicae circulares and villi to increase the surface area of that part of the GI Tract.

  • Muscularis

    • The muscularis externa consists of an inner circular layer and a longitudinal outer muscular layer.
    • The circular muscle layer prevents food from traveling backward and the longitudinal layer shortens the tract.
    • The layers are not truly longitudinal or circular, rather the layers of muscle are helical with different pitches.
    • The inner circular is helical with a steep pitch and the outer longitudinal is helical with a much shallower pitch.
    • The pylorus of the stomach has a thickened portion of the inner circular layer: the pyloric sphincter.

  • How Skeletal Muscles Are Named

    • The fibers of the circular or sphincter muscles are arranged concentrically around an opening or recess.
    • Skeletal circular muscles are different from smooth muscle equivalents due to their structure and because they are under voluntary control
    • The orbicularis oris which controls the opening of the mouth is an example of a circular muscle.
    • The four types of muscle; parallel (fusiform and non-fusiform), circular, convergent and pennate (uni, bi and multi).

  • Bilaminar Embryonic Disc Development

    • Simultaneously, morphological changes ocur in the embryoblast that result in the formation of a flat, almost circular bilaminar plate of cells--the embryonic disk--which includes the epiblast and the hypoblast.

  • Lines of Cleavage and Surgery

    • Langer punctured numerous holes at short distances from each other into the skin of a cadaver with a tool that had a circular-shaped tip, similar to an ice pick.

  • Synovial Joint Movements

    • Rotation is a circular movement around a fixed point.

  • Overview of Urine Transport, Storage, and Elimination

    • Circular muscles called sphincters help keep urine from leaking.

  • Elastic Arteries

    • In these large arteries, the amount of elastic tissue is very considerable and the smooth muscle fiber cells are arranged in 5 to 7 layers in both circular and longitudinal directions.

  • Microscopic Anatomy of the Stomach

    • The pylorus is surrounded by a thick circular muscular wall which is normally tonically constricted, forming a functional (if not anatomically discrete) pyloric sphincter, which controls the movement of chyme.