608 GLOSSARY. 



Sigmoid. Parts are so called from their resemblance to the letter S ; from 2, 



the letter Sigma, and siSos likeness. 



Sphenoid. From cfyriv a wedge, and eiSos likeness ; shaped like a wedge. 

 Sphincter. The name of several muscles, whose office it is to shut up the apert- 

 ure around which they are placed ; from a$iyy& to shut up. 

 Splanchnic. From o-TrXay^vof an entrail. 



Symphysis. A connexion of bones ; from </^vw to grow together. 

 Synarthrosis. A connexion of bones ; from cw with, and apOpov a joint. 

 Synchondrosis. A species of union of bones by means of cartilage ; from aw 



with, and %ovSpos a cartilage. 

 Synneurosis. A species of connexion of bones by means of membrane ; from aw 



with, and vsvpos a nerve; because membranes, ligaments, and tendons, were 



by the ancients considered as nerves. 

 Syssarcosis. A species of connexion of bones by means of muscle ; from aw 



with, and <rap flesh. 

 Systole. The contractile motion of the heart and arteries; from o-voTsAAa to 



contract. 



T. 



Tendon. From rcivw to extend. 



Thorax. 6pa|. The breast or chest. 



Thyroid, From dvpeos, a shield, and eitos likeness ; shaped like a shield. 



Trachea. The wind-pipe ; so called from its roughness ; from Tpa%vs rough. 



Trochanter. A process of the thigh-bone, so called from rpo^oj a wheel. 



u. 



Ulna. A name for the cubit ; from <^\tvr\ the cubit. 



Ureter. The canal which conveys the urine from the kidney to the bladder ; 



from ypov the urine. 

 Urethra. The passage through which the urine passes from the bladder ; from 



upov the urine. 

 Uvea. The posterior lamen of the iris, so called because in many animals it is 



of the color of unripe grapes ; from uva an unripe grape. 

 Uvula. The conical substance which hangs down from the middle of the soft 



palate ; so called from its resemblance to a grape. A dim. of uva a grape. 



V. 



Valves. From valves, folding doors. 



Vertebra. The bones of the spine are so called : from verto to turn. 



X. 



Xiphoid. So called from the resemblance to a sword ; from t^o? a sword, and 

 eiSos likeness. 



z, 



Zygoma. The cavity under the zygomatic process of the temporal bones ; from 

 a yoke. 



