Circular

Examples of Circular in the following topics:

• Muscularis

  • The muscularis externa consists of an inner circular layer and a longitudinal outer muscular layer.
  • 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.
  • General structure of the gut wall - the muscularis externa is labeled "circular muscle" and "longitudinal muscle" here

• 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).

• 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.

• 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.

• Functional Classification of Joints

• 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.

• Anatomy of the Digestive System

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

• 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 considerable and the smooth muscle fiber cells are arranged in 5 to 7 layers in both circular and longitudinal directions.

• Synovial Joint Movements

  • Rotation is a circular movement around a fixed point.