PETROMASTOID 



1058 



PEYER'S GLAND 



Petromastoid (pet-ro-tnas'-toid) \jrtTpa, stone ; fiaorog, 

 nipple; fWoc, like]. Pertaining to the petrous and 

 mastoid portions of the temporal bone. P. Bone, a 

 bone of fetal and early infantile life, which in the hu- 

 man species soon becomes merged into the temporal 

 bone. P. Canal, a short passage connecting the mas- 

 toid sinuses and the tympanic cavity. P. Foramen, 

 the tympanic orifice of the petromastoid canal. 



Petrooccipital (pet-ro-ok-sip' -it-al) [ncTpa, stone; occi- 

 put, occiput]. Pertaining to the petrous portion of 

 the temporal bone and to the occipital bone. 



Petropharyngeus (pet-ro-far-in' -je-us) \jttTpa, rock ; 

 (papvy^, pharynx]. A small muscle arising from the 

 lower surface of the petrous portion of the temporal 

 bone, and blending with the constrictors of the 

 pharynx. 



Petrosa (pet-ro'-sah) [nfrpa, rock]. The petrous por- 

 tion of the temporal bone. 



Petrosal {pet-rot -ml) [nerpa, rock]. Pertaining to the 

 petrous portion of the temporal bone. As a noun, the 

 petrous portion of the temporal bone itself. P. Bone, 

 in biology, one of several portions of the temporal 

 bone in the human fetus and in other animals. P. 

 Nerves. See Nei-ves, Table of. P. Sinus, a name 

 given to two venous sinuses, superior and inferior. 

 The former is situated along the superior border of the 

 petrous portion of the temporal bone ; the latter, near 

 the posterior border. P. Vein. Same as P. Sinus. 



Petrosalpingopharyngeus {pet' '-ro-sal- ping' '-gofar- 

 in'-je-us). Same as Petropharyngeus. 



Petrosalpingostaphylinus [pet' ' -ro-sal-ping' ' -go-stafil- 

 i f -nus). Synonym of Levator palati. See Muscles, 

 Table of. 



Petroselinum (pet-ro-se-li' '-mini) \jri-pa, rock ; ofkivov, 

 parsley]. A genus of umbelliferous plants including 

 the common parsley. 



Petrosomastoid (pet-ro-so-mas'-toid). Synonym of 

 Petromastoid. 



Petrosphenoid (pel-ro-sfe' '-noid) [ne'rpa, rock; otyyv, 

 wedge ; eUoc, like] . Pertaining to the petrous portion 

 of the temporal bone and the sphenoid bone. P. 

 Suture, the suture between the temporal bone and 

 the great wing of the sphenoid bone. 



Petrosquamosal, Petrosquamous (pet' ' -ro-skwa-mo' '- 

 sal, pet-ro-skwa' -nius) [irerpa, rock ; squama, scale]. 

 Pertaining to the petrous and squamous portions 

 of the temporal bone. P. Fissure. Same as P. 

 Suture. P. Sinus, a venous passage formed in the 

 dura at the junction of the petrous and squamous por- 

 tions of the temporal bone. It opens into the lateral 

 sinus. P. Suture, the line of juncture of the squa- 

 mous and petrous portions of the temporal bone. 



Petrostaphylinus (pet-ro-staf-il-i' -nus) . Synonym of 

 Levator palati Muscle. See Muscles, Table of. 



Petrous (pe'-trus) [nerpa, rock]. Stony; like a rock. 

 See Petrosal. P. Portion. See Temporal Bone. 

 P. Ganglion. See Ganglia, Table of. P. Sinus. 

 See Petrosal Sinus. 



Pettenkofer's Method. A method of estimating CO, 2 

 in the air. See Ventilation. P.'s Test. A qualitative 

 test for the presence of biliary acids. A few drops of 

 the suspected liquid, as the urine, are dropped into a 

 fresh solution of sugar and dilute sulphuric acid. If 

 biliary acids be present a purplish-crimson color is 

 produced. See Tests, Table of. P.'s Theory. A 

 theory of the development of cholera. It is that chol- 

 era is not communicable from man to man, but requires 

 certain conditions of the soil in order to develop its 

 infectious character. These conditions are, in the main, 

 a low Mage of tin' subsoil water, a certain porosity of 

 the soil, and the presence of substances that can serve 

 as food for low organisms. Pettenkofer succinctly states 



his theory as follows: The cholera germ, " X," by 

 reason of certain local and chronologic conditions 

 of the soil, " Y," produces the cholera-poison, " Z. 

 just as the yeast-plant, " X," develops from the sugar- 

 solution, " Y," the poisonous alcohol, " Z." The chol- 

 era-poison, " Z," enters the human body with the in- 

 spired air. Pettenkofer's theory is not generally 

 accepted, as it has been proved that the cholera- 

 bacillus is the cause of the disease, and enters the 

 body chiefly with the drinking-water. 



Petticoat Tube. A device for arresting hemorrhage 

 after lithotomy. It consists of a vulcanite tube, the 

 open end of which is thrust through a small hole in 

 the middle of a piece of linen about four inches 

 square, the linen being firmly tied around the tube 

 about half an inch from the end. This end is lubri- 

 cated and thrust into the bladder, and the space be- 

 tween the tube and the petticoat is stuffed with strips 

 of lint, thus producing compression. 



Peucedanin (pu-sed / -an-in) \jTEVKtfiavov, hog-fennel], 

 C 12 H 1? 3 . A crystalline body obtained from the root 

 of species of Peucedanum. 



Peucedanum (pu-sed'-an-itm) [ireviddavov , hog-fen- 

 nel]. An umbelliferous plant, of which several species 

 have slight medicinal value. It is now rarely used; 

 it yields peucedanin. Unof. 



Peumus (pn'-mus) [native Chilean name]. A genus of 

 apetalousmonimiaceous plants. P.boldus. SeePoldo. 



Pexis (peks'-is). Synonym of Concretion. 



Peyer's Gland or Peyer's Patch [Johann K. Peyer, 



- muscular 

 fibers. 



Longitudinal Section thkoit.h a Pf.yf.r's Pai 

 Small Intkstim ok \ Dog. (From 



Swiss anatomist 1653-1712]. The agminat 



