sigmoid valves

2 definitions found

sigmoid valves - Collaborative International Dictionary of English v.0.48 :

  Semilunar \Sem`i*lu"nar\, a.
     Shaped like a half moon.
     [1913 Webster]
  
     Semilunar bone (Anat.), a bone of the carpus; the lunar.
        See Lunar, n.
  
     Semilunar valves, or Sigmoid valves (Anat.), the valves
        at the beginning of the aorta and of the pulmonary artery
        which prevent the blood from flowing back into the
        ventricle.
        [1913 Webster]

  Sigmoid \Sig"moid\, Sigmoidal \Sig*moid"al\, a. [Gr. ???; ???
     sigma + e'i^dos form, likeness: cf. F. sigmo["i]de.]
     Curved in two directions, like the letter S, or the Greek
     [sigmat].
     [1913 Webster]
  
     Sigmoid flexure (Anat.), the last curve of the colon before
        it terminates in the rectum. See Illust. under
        Digestive.
  
     Sigmoid valves. (Anat.) See Semilunar valves, under
        Semilunar.
        [1913 Webster]