PITTED 



1106 



PIXOL 



Pitted (pil'-ed) [ME., pit, a pit]. Marked by inden- 

 tations or pits, as from smallpox. 



Pitting (pit'-ing) [ME., pit, a pit"]. The formation 

 of pits ; also the quality of preserving, for a short 



• time, indentations made by pressing with the finger. 



Pituita (pit-u'-it-ah) [L.]. Phlegm ; mucus. 



Pituitary (pit-u'-it-a-re) [ pituita, phlegm]. Mucus; 

 secreting or containing mucus. P. Body, a small, 

 reddish-gray vascular body, weighing about ten grains, 

 contained within the sella turcica. The pituitary 

 body consists of two portions, the large anterior, oral 

 and the small posterior, cerebral division. The anterior 

 lobe is derived as a diverticulum from the primitive 

 oral cavity, and, as such, is lined with oral ectoderm, 

 while the posterior lobe descends as an outgrowth 

 from the floor of the primary interbrain. The stalk 

 of this outgrowth remains as the infundibulum. The 

 pituitary body has attracted much attention on account 

 of pathologic changes in its structure in certain obscure 

 diseases, such as acromegalia, myxedema, and others. 

 In some cases of the affection first named, it has been 

 much enlarged. It is called also hypophysis cerebri and 

 pituitary gland. P. Diverticulum, a flask-like out- 

 growth of the middle of the upper posterior portion of 

 the buccal cavity of the embryo. It takes part in the 

 formation of the pituitary body. P. Fossa. See 

 Fossa. P. Gland. See P. Body and Gland. P. Mem- 

 brane, the Schneiderian membrane. P. Space, 

 in the embryo, the open space at the base of the 

 skull that subsequently becomes the seat of the pitui- 

 tary body. It corresponds to the sella turcica of 

 the sphenoid bone. 



Pituitous (pit-u' '-it-us) [pituita, phlegm]. Contain- 

 ing or resembling mucus. 



Pituri {pit-u' -re). Same as Duboisia. 



Piturin (pit'-u-rin). A liquid alkaloid obtained from Du- 

 boisia hoptvoodii. It is probably identical with nicotin. 



Pityriasis (pit-ir-i'-as-is) [Trirvpov, bran]. A term 

 formerly applied to various pathologically dissociated 

 skin-affections, the most striking clinical feature of 

 which is the presence of fine, branny desquamation. 

 Also a synonym of Seborrhea. P. cachecticorum. 

 Same as Seborrhea. P. capillitii, P. capitis. See 

 Alopecia furfuracea. P. circinata et marginata, 

 an eruption of rose-colored spots on the trunk, the 

 limbs, and in the axillse. It is of parasitic origin. 

 P. gravidarum ; Chloasma gravidarum ; the dis- 

 coloration of the skin sometimes observed during 

 pregnancy. P. infantilis, a desquamative eruption 

 attacking infants ; it is probably eczema. P. macu- 

 lata et circinata. See P. rosea. P. nigra, pity- 

 riasis with pigmentation occurring in the aged. Also, 

 a papular eruption tenninating in slight desquama- 

 tion, which attacks children brought to England 

 from India. P. nigricans. Synonym of Chromi- 

 drosis. P. pilaris. See Keratosis pilaris. P. rosea ; 

 P. maculata et circinata ; Herpes tonsurans maculo- 

 sus ; an acute inflammatory skin-disease characterized 

 by macular or circinate lesions, occurring mostly on 

 the trunk. The eruption consists at first of rosy-red 

 spots, which later become brownish. The lesions are 

 round, but owing to their tendency to recover at the 

 center and to extend peripherally, gyrate and irregu- 

 lar figures are formed. Furfuraceous desquamation is 

 a marked feature. P. rubra ; Dermatitis exfoliativa ; 

 a chronic inflammatory skin-disease, beginning in one 

 or more localized patches, which coalesce and gradu- 

 ally invade the whole body. The skin may be of a 

 dark or vivid red or bluish-red. There is no infiltra- 

 tion and no moisture, but there may be edema of the 

 lower limbs. The desquamation is very free ; the 

 scales are thin and papery on the general surface, im- 



bricated, and from a line to an inch or more in di- 

 ameter. The disease lasts months or years, and gen- 

 erally ends fatally from progressive emaciation and 

 exhaustion, or from some intercurrent affection. P. 

 rubra pilaris ; Lichen ruber acuminatus ; a primar- 

 ily non-inflammatory disease of the skin, characterized 

 by follicular papules, with horny centers, tending to 

 become general or even universal in distribution. The 

 papules are hard, dry, brownish-red, and seated at the 

 hair-follicles. An atrophied hair occupies the center, 

 and is surrounded by a sort of horny sheath which 

 penetrates into the follicle. The papules vary in 

 size from a small pin's head to a millet-seed, and are 

 most abundant on the limbs. Deep folds are formed 

 at the joints. Pruritus is absent or only slight. The 

 course is slow and irregular ; the pathology is un- 

 known. P. simplex. See Alopecia furfuracea. P. 

 senilis, pityriasis of the aged. P. tabescentium. 

 See Seborrhcea universalis. P. versicolor. See 

 Tinea versicolor. 



Pityrisma (pit-ir-iz'-mah). Synonym of Pityrisasis. 



Pityroid (pit'-ir-oid) [irirvpov, bran ; rfdog, like]. 

 Furfuraceous, branny. 



Pivot (piv'-ol) [Ft., pivot, a pivot]. A pin on which a 

 wheel turns. P.-joint. See Cyclarthrosis. P. 

 Tooth, an artificial crown, designed to be applied to 

 the root of a natural tooth, by means of what is usually 

 termed a pivot, but more properly a dowel or tenon. 



Pivoting (piv'-ol-ing) [Fr. , pivot, a pivot]. The fixa- 

 tion of an artificial crown to a tooth by means of a 

 pivot or pin. 



Pix (pihs) [L. : gen., Picis"]. Pitch. The resinous ex- 

 udation of certain coniferous trees. The varieties in 

 common use are chiefly Burgundy Pitch, from the 

 Norway spruce, Abies excelsa , andCanada Pitch, from A. 

 canadensis. Pitch melts at about the temperature ol 

 ing water and softens by the heat of the human 

 It is soluble in glacial acetic acid and in absolute 

 hoi, and is used mainly as the base of plasters. Picis 

 burgundicae, Emplast., Burgundy pitch So, i 

 oil 5, yellow wax 15. P. canadensis, Emp.. 

 tains Canada pitch, 90, yellow wax IO parts. Picis 

 cantharidatum, Emp., Burgundy pitch 92, canthar- 

 ides cerate 8 parts. P. liquida, tar, an empyreumatu. 

 oleo-resin obtained by the destructive distillation of 

 various species of pine ; it is blackish-brown in 

 and possesses a well-known taste and odor. It 

 yields oil of tar, pyroligneous acid, creasote, and car 

 bolic acid. It is a complex mixture of resins and 

 hydrocarbons. Externally, it is a stimulant to tin 1 ; 

 skin; internally, a gastro-intestinal irritant. It i>M'i 

 viceable in scaly diseases of the skin and of ben< 

 bronchitis. Dose 3J-ij. P. liq., Infus., unof., 

 by shaking I part of tar with 4 of water frequ 

 for 24 hours. Dose Oj-ij daily. P. liq., Ol., a 

 tile oil distilled from tar; it consists of various !r 

 carbons, phenols, etc, and is used locally. P. tiq-i 

 Syr., contains 6 per cent, of tar in syrup. I 

 3 ij-3 ss. P. liq., Ung., equal parts of tar and 

 P. Liq., Vin., wine of pitch, unof., tar 3 xvj.j 

 in, white wine, honey aa 3 viij, acetic acid ,^j, bo 

 ing water Ovj. Carbonis detergens, Liq., urn 

 alcoholic solution of coal-tar, a useful antiseptic 

 putrid sore-throat, etc. Vapor olei pini sylvestris 

 (B. P.) Inhalation of fir-wood oil, used in 

 throat and chronic laryngitis. 



Pixol { piles' -ol) [pix, pitch ; oleum, oil]. A disiBB 

 ant prepared by dissolving a pound of gr< 

 three pounds of tar and slowly adding a solution ol a 

 tie over three ounces and a half of either potash or so 

 in three pounds of water. For use one r :l " "' ' 

 syrupy liquid thus formed is added to 1 9 part 



