Page:The New International Encyclopædia 1st ed. v. 12.djvu/263

LIGAMENT. LIGAMENT (Lat. Ufjamcntum, band, from liyare, to bind). A cord, band, or membranous ('.pansiou of fibrous tissue passing in a fixed direction from one bone to anotlier, and serving to limit and control the movements of joints. Ligaments are divided into three classes: (I) Cdiinular {hat. capsula.a small box) ; (2) fa-lcic- iihir (I^at. fascis, a bundle) : and (3) funicular I Lat. /i/H IS, a rope) . (1) Capsular ligaments are cylindrical expansions which are attached by ontJnf L-fUg.- inttros.lig. excoLsmfiUtj postJnftrCUg. tiiscpost. Ug. posLfascex.LU^ m..fasaex.l.Ug. OLcalMstMg. ~UU'.cal-cu-. (Im-.cal.ca. dor.cU:Scap.lig.

EXTERNAL VIEW OF THE LIGAMENTS OF THE FOOT AND A.NKLE. aat.inf.t.-f.lig., antero-iiiferior tibio-flbular ligament : &nt. life., anterior lia-aineiit (-)f ankle-joint : iuteros.Ug. . ijnX^T extrptnity of the interosseous ligament ; ex,caI.scapJi^., ex- ternal caicaneo-8caphoid ligament; post. in/; t.-/t/i£*.,po6tero- inferior tiliio-Iiljular ligaiiieul ; iksc.post.lig., fascioliIuH of posterior ligament uf anlile; post.fasc.exj.hg., posterior fascii-ulus of external lateral ligament; w.faBc.ex.l lig., middle fasciculus of external lateral ligament of ankle; ex.cnl.ast.Ug., external calcaneo-astragaloid ligament; dor.cu.scup.lig., dorsal cubo-scaphoid ligament; mt.eal. (.'«., internal calcaneo-cuboid ; rfor.ca/.eu., dorsal calcaneo- cuboid.

their extremities around the margins of the ar- ticulating surfaces composing the joint. (2) Fas- cicular ligaments are flattened bands of various shapes and widths. (3) Funicular ligaments are round 1)11 section, and shaped like a heavy cord, as tlio lii/iiiiicHliiin teres of the hip-joint. Two ligaments in the body, the lii/amentum kubllinii and the ligamentum nuchee. both of which are connected with the spinal column, are composed of j-ellow elastic tissue. All other ligament.s in the body are composed of white lilirous tissue.

The various ligaments result from metamor- phosis and retrogression of muscle-tissue, with init few exceptions. In a fcAV cases ligaments represent llie degenerate remains of cartilage or bone. Cajisular ligaments are derived from the periosteum, and are strengthened by the in- corporation of tendons of adjacent muscles. The term 'migration of muscles' is applied in myology to an alteration of a point of attach- ment of a muscle, occurring during tissue changes in low vertebrate forms, whereby a point of origin of a muscle shifts from a posi- tion below a joint, for example, to a positiim above the joint. The former position of the muscle end is occupied by a ligament under which form part of the muscle tissue persists. An excellent example is the external lateral ligament of the knee-joint, which represents the tendon of the peronens Ionqjt&. this muscle hav- ing migiated from the femur to the head of the fibula. See .Joints. Consult Morris, Human Anatomy (Philadelphia, 1002).

LIGAMENT, in Comp.r.tive. .tomy. The presence of true ligaments among inverte- brates is doubtful, unless we include under the term all strands of connective tissue which serve to bind one part to another, such as that in the "hinge' of bivalved mollusks. This band is composed of two layers, of which the inner i.s ery elastic, and has somewhat the appearance of cartilage. See Pelecvpod.v.

Among vertebrates ligaments are found of great variety of form and function, especially among birds and mammals. Of these, one which is but sliglitly developed in man, though largely develo])ed in the gorilla, deserves a brief de- scription. This is the ligamentum nuchw or neck-ligament, which assists in the support of the head in long-necked ungulates, as the horse, camel, and ox. It is composed of yellow, elastic, librous tissue and is associated with a remark- able development of the neural s])ines of the an- terior thoracic vertebra-, to which its posterior end is attached. The anterior end is connected with the base of the skull and some of the an- terior cervical vertebra;. This ligament is well known to butchers, by whom it is called 'pax- wa.x' or 'faxwax.' A similar ligament is present in most other mammals, but does not reach such a high development. The ligament whose func- tion it is to operate the elevated '.sheathed' claws of cats will be found explained and illustrated under Cat.

LIGAN. See Flotsam.

LIGAO, Is-ga'd. A town of Luzon, Philiiv pines, in the Province of Albay (Map: Philip- pine Islands, H 6). It is situated on the main road of the province, about 1.5 miles northwest of Albay. Population, in 1896, 17,370.

LIGATURE (Lat. liqatura, band. from Ugare, to bind). A thread of silk, catgut, or other material, tied around a blood-vessel to arrest hemorrhage or to diminish the flow of blood to an aneurism or tumor. The use of liga- tures was known many centuries ago. the old Roman surgeons using them with considerable skill. During the Dark Ages they were forgotten, and it was not until .Ambroise Pare (q.v.) in- troduced them (about 1536), while in Italy with the army of Rene de Mont-.Jean, that their use was slowly revived. Up to this time hemorrhage from wounds was stopped by searing them with red-hot irons, or plunging the part in hot pitch. .Tnhn Hunter, an English surgeon, first advocated the ligature in the treatment of aneurisms by tying off the artery at some distance from the aneurismal sac. The materials from which liga- tures have been made are very numerous. Those in most common use, however, are silk, catgut, and silkworm gut. Catgut, like most animal sub- stances, is quickly absorbed by the tissues and is used for buried ligatures. Silk is not absorbed, but has the advantage of being much stronger than catgut (and therefore more suitable for deli- cate work) and more easily sterilized. Silver wire is useful where considerable masses of tissue have to be included in the ligation.

Ligatures are employed for arresting hemorrhage in arteries or veins either at the time of an amputation or other operation in which a vessel is divided, or when an artery is wounded accidentally; for removing tumors of various kinds such as hemorrhoids: for diminishing the supply of blood to a part, as in the case of inoperable malignant tumors, whose growth may be sometimes temporarily arrested by cutting off