GLOSSARY. 607 



Pericranium. The membrane which covers the bones of the skull ; from nepi 



around, and xpaviov the cranium or head. 

 Periosteum. The membrane which surrounds the bones ; from ntpi areund, and 



oseov a bone. 



Peristaltic motion of the intestines ; from TreptjeAXc.) to contract. 

 Peritoneum. The membrane lining the abdomen, and covering its viscera : from 



neptreiva to extend around. 

 Phalanx. The bones of the fingers and toes are called phalanxes, from their 



regular situation, like a <paXay| or arrangement of soldiers. 

 Pharynx. A membranous bag at the end of the mouth ; a-no ra <f>epeiv because 



it conveys the food into the stomach. 

 Phrenic or diaphragmatic nerve. <&psvss the diaphragm from ^>prjv the mind ; 



because the ancients supposed it to be the seat of the mind. 

 Pia Mater. The innermost membrane of the brain ; so called because it em- 

 braces the brain as a careful mother folds her child. 

 Pleura. The membrane lining the thorax ; ir\svpa the side. 

 Plexus. A kind of network of vessels or nerves, from plecto, to weave together. 

 Psoas. A muscle so called ; from ipoa the loin, being situated in the loins. 

 Pterygoid process. From irrepv!- a pen or wing, and ei Joj likeness, so called from 



its likeness to a pen or wing. 

 Pylorus. The lower orifice of the stomach, which opens into the intestines ; 



from n-uXow to guard an entrance, because it guards as it were the entrance of 



the bowels. 



R. 



Eaphe. A suture ; from parrrw to sew. 



Renes. The kidneys, a ru psiv, because through them the urine flows. 



Retina. The net-like expansion of the optic nerve, on the inner surface of the 

 eye ; from rete a net. 



Rhomboides. A muscle so called from its shape ; from pa^Sag, a geometrical fig- 

 ure, whose sides are equal, but not right-angled, and eiSog a likeness. 



Rotula. The knee-pan 5 a dim. of rota a wheel, from its shape. 



S. 

 Sacrum. A bone so called ; from sacer a word, because it was once offered in 



sacrifices. 

 Salvatella. A vein of the foot, so called because it was thought that opening it 



preserved health, and cured melancholy ; from salvo to preserve. 

 Sanguis. The blood ; airo r aativ yvia, because it preserves the body. 

 Sartorius. A muscle, so called because tailors cross their legs with it ; from 



sartor a tailor. 

 Scapha. The depression of the outer ear, before the anti-helix j from ana^r, a 



little boat or skiff. 

 Scaphoides. A bone of the carpus, so called from its resemblance to a skiff; 



from (TKa<pr) a skiff, and eido$ likeness. 

 Sclerotic. A term applied to the outermost or hardest membrane of the eye ; 



from <tK\ripoo) to make hard. 

 Sesamoid bones. From <jr\aapr] a grain, and eiJoj likeness ; from their resemblance 



to the semen sesami. 



