I N T 



I N T 



INTERCIDENT Pui.se, a term iifed by medical in fituation, attachments, and number. They commcirc 



writers to exprefs a fort of pulfe, io wliich between two re- 

 gular (Irokes there is perceived a third irregular. 

 INTERCOLUMNiATlON.orlsTKUcoLUMNATioN, 



behind at the angles of the ribs, and extend in front 

 the ends of the cartilages. They are attached to the inntr 

 borders of the edges of tlie ribs ; and their fibres proceed 



in Arch't'.cdure, fio-nifies the fpace between two columns, jn an oblique courfe from above do^vnwaids 

 See the plan of Bifilic, in Plate Arcb'tteauif. wards, fo as to decilflate thofe of llie external ftratiim, 



Vitruvius calls 'it intcn-olunmium ; which, according to They form thinner ilrata than the external intercofta' 



that author, is of five kinds : \\z. picnq/lyle, A, one dia 



more tendinous, have their fibres lefs oblique and con- 



fer and a half ; j7/?v/f, B, two diameters ; r///7)'/f, C, two and fcqueiitly rather fhorter. Sometinies a fafciculus of one 



a quarter diameters, which is tlie mofl graceful ; diajlyk, D, or two of the internal inlercoftals pafies over one rib 



tiu-ee diameters ; and arsojlyh, E, four dian^.eters ; which to be fixed into the fecond. Thefe are vcfy irregular in 



fee explained under their proper heads, PicxosTVLE, &c. number, fi/c, and fituation, and do not require a feparate 



'I'lie intercolumniation, or fpace between the columns to tha defcription : they have however been noticed as diftinft 



arcade F, is feven and a half diameters ; and the interco- mufclcs by the name of /tfc.5/7.,'/ ■/. 



iumniation wherein there is a fpace, G, of only one halt a As the external inlercoftals oiiiy reach to the ends of the 



diameter, is called coupling columns, an invention afcribed bony portions of the ribs, and the internal do not extend 



to the moderns. beyond the angles, a fmall part of the intcrcollal intervals 



From a medium, fome authors have laid down the follow- in front and behind is filled only by a fingle ftratum of 



ing proportions ; in the Tufcan order, the intercolumniation, fibres ; but the remaining and largeft part is clofed by two 



is To be four diameters of the body of the column below 

 the Doric, three ; in the Ionic, two ; in the Corinthian, two 

 one quarter ; and in the Compofite, one and a half. 



layers. 



The internal intercoflal mufcles are covered by the 

 ternal, from which they are partly feparated by the vcfltis 



INTERCOMMONING is when tiie commons of two and nerves of the fame name. Where the former end in 

 manors lie together, and the inhabitanls of both have, time front, the latter are covered by the thin aponeurofis already 

 <iut of mind, caufed their cattle to feed promifcuoufly in defcribed. They are lined on the infide by the pleura. 



each. 



The kvalores co/Ianim (les tranfvcrfo-colliens) 



INTERCOSTALES, in Anatomy, the mufcles which thin, and fiat fafciculi of a radiated form, placed behind 



fill the intervals of the ribs, and are arranged in two the external inlercoftals, from which they are very di!b'n6t. 



ftrata, -diftinguilhed by the epithets of external and internal. They are twelve in number, as each rib has one. Each of 



This region of the body includes alfo the levatores coilarum thefe mufcles has an aponeurotic origin from the apex of 



and triangularis fterni. 



the tranfverfe procefs of the 



^fponding dorfal vertebr 



The inteicoi'lal mufcles (intercoftiens) confift of two or from the ligament connecting the rib to that procefs ; 

 thin mufcular planes in each of the intercoftal intervals, hav- its fibres pafs obliquely downwards and forwards, and, 

 ing their fibres difpofcd obliquely, and attached to the margins growing broader, are attached to the upper edge of the 

 of the ribs, which bound tlicfe fpaces. rib immediately below. The levator of the firft rib arifes 

 The f.v/i';-«<;/;n/i';ro/?i!/ mufcles are attached by their upper from the tranfverfe procefs of the feventh cervical ver- 

 edges to the outer border of the lower margins of the ribs, tebra, that of the fecond from the correfponding procefs of 

 by means of tendinous and flefiiy fibres. Their fibres are the firft dorfal vertebra, and fo on to the twelfth. They in- 

 diretlcd obliquely downwards and forwards ; and they are at- creafe in fize regularly from above downwards, 

 tached below by an infertion exactly refembling the former Befides thefe, each of the two, three, or four lower ribs 

 to the upper edge of the fuccecding rib. Various blood- has a longer fafciculus, arifing from the tranfverfe procefs 

 veftels and nerves penetrate them in different parts of the of the fecond vertebra above it. Thefe are called levatores Ion- 

 trunk. Their origin begins at that part of the rib which is giores, to diftinguifti them from the former, which are named 

 articulated to the tranfverfe procefs of the vertebra, and is breviores. Theyhavethin tendinous origins from the tranf- 

 continued towards the front as far as the jimftion of the verfe procefies, pafs over the ribs immediately below thefe 

 bone with the cartilage: beyond this point the intervals of proceiles, and are inferted into the upper borders of the fnc- 

 the cartilages are filled with their aponeurotic fibres, which ceeding ribs : thus tlie firft levator loiigior, arifing from the 

 have fimilar attachments and direftion to the external inter- tranfverfe procefs of the feventh dorfal vertebra, is fixed to 

 coftal mufcles. the ninth rib. 



As the fibres of thefe external intercoftal mufcles pafs Thtfe mufcles are placed between the external inlercoftals 



from above obliquely downwards and forwards, they form and the facrolumbalis and longiffimus dorfi. 



towards the front acute angles with the upper and obtufe The triangularis Jlerni (llerno-coftalis, fterno-coftien) is a 



angles with the lower ribs. The pofterior fibres are more very thin flattened ftratum, of a triangular figure, placed 



oblique than the anterior. The ftratum placed under the behind the cartilages of the ribs. It is fixed to the pofte- 



firft rib, between it and the fecond, is called the firft inter- rior part of the edges of ihe enfiform caitilage, and of the 



coftal muftle ; and thofe of the following intervals, accord- fecond bone of tiie ftern\mi, as high as the cartilage of the 



ing to the order in which they fuccecd, the fecond, third, fourth rib, by aponeurotic fibres, which cover a confider- 



&c. to the eleventh. able portion of the mufcle. The flelliy fibres, direfted 



Theexternal intercoftal mufcles are covered on their outer outwards and upwards, and more oblique as they are nearer 



furfa'ces by moft of the broad mufcles of the trunk, as the to the upper part, form at firft a continuous broad layer, 



two pcdtorals, obliquus externus abdominis, ferratus anticus, and then divide into feparate portions attached by thin apo- 



and the ferrati poftici ; and in fome degree behind by the neurofes to the third, fourth, fiftii, and fixth ribs. It is 



facrolumbalis and longiffimus dorfi. They correfpond on the conti"uous below with the tranfverfus abdominis ; cerre- 



internal furface to tht- internal inlercoftals, from which they fponds in front to the cartilages of the four laft true lib?, to 



Hre partly feparated by the intercoftal velfels and nerves, the internal intercoftal mufcles, and to the mammary velTels ; 



i>ear the vertebral column they are covered by the pleura. and behind to the pleura, and for a fmall fpace to the 

 Tiv iniirnal iiili-rcojlal mufcles exaitly refcmble the former diaphragm. 



The 



