the attached margin of the falx cerebelli opening into the torcular Hero phil i

See lateral s. petrosquamous s. A venous s. running along the petrosquamous suture and opening into the transverse s.; believed to be a relic of a fetal communication with the internal jugular vein, pilonidal s. Syn.: congenital lumbosacral fistula. See foveola coccygea, under foveola. s's of Cuvier. See under Cuvier. s. Morgagni. See lacunae Morgagni, under lacuna, s's of Valsalva, and ventricle of the larynx, under ventricle, s'es of Valsalva. Dilatations of the aorta and pulmonary artery opposite the segments of the aortic and pulmonary valves, s. pleurae. The spaces in the pleural sac along the lower and inferior portions of the lung which the lung does not occupy, s. prostatic us. See uterus masculinus, under uterus. s. pul monal is. The atrium of the left auricle of the heart, s. pyriform is. See fo a laryngopharyngea, under fo a, s. terminal is. A vein that encircles the vascular area of the blastoderm and empties either by one trunk, the anterior vitelline vein, into the left vitelline vein or by two trunks into both vitelline veins, s. trans versus per i card i i. An opening connecting the prolongation of the pericardium which covers the pulmonary artery and aorta with that covering the auricles, s. tuberculi (o is metacarpi). A depre ion upon the external surface of a metacarpal bone just above its distal articular surface, s. vinos us. See canal of Schlemm, under canal, sphenoidal s'es. Air s'es which occupy the body of the sphenoid bone and connect with the nasal cavity, sphenoparietal s. i. A vein uniting the cavernous s. and a meningeal vein. 2. The portion of the cavernous s. below the ensiform proce . straight s. A s. which is continuous with the inferior longitudinal s. and, running along the junction of the falx cerebri and tentorium, is continuous with the lateral s. superior longitudinal s. A triangular canal which runs along the upper edge of the falx cerebri, beginning in front at the crista gall i and terminating at the torcular Hero phil i. superior petrosal s. A venous canal running in a groove in the petrous portion of the temporal bone, torcular i an s'es. Sinuses that open into the torcular Hero phil i. transverse s. i. A s. uniting the inferior petrosal s'es. 2. A venous network in the dura over the basilar proce of the occipital bone. It opens into the inferior petrosal s'es and the anterior spinal veins, urinogenital s., urogenital s. 1. The canal or duct into which, in the embryo, the Wolffian ducts and bladder empty and which opens into the cloaca. 2. In comparative anatomy, the common receptacle of the genital and urinary ducts, uterine s'es. The veins of the uterus when in a state of dilatation due to enlargement of the organ, as in pregnancy, uteroplacental s'es. Slanting venous channels which i ue from the placenta at its uterine surface by piercing the decidua serotina, and serve to convey the maternal blood from the inter villous lacunae back into the uterine veins, venous s. A s. conveying venous blood. See also meatus venosus, under meatus. vertebral s'es. Veins within the bodies of the vertebrae. [Lat, sinus, hollow, fold.] sinusitis (si-nus-i'tis). Inflammation of the living membrane of a sinus. < [Lat., sinus, mation.]a curve, a bend, + Gr., it is, in flam siphon (si'fon). A bent tube by means of which a continuous flow of liquid can be maintained so long as the outlet of the s. is below the level of the surface of the body of liquid from which the stream is drawn, although part of the s. rises above that surface. [Gr., siphon, tube.]