I shall confine my observations, in the following chapter, to the membranous, and the fasciculated fibrous structures, except in the instance of periosteum, which I shall consider as fully as can be done, without entering into the subject of diseases of bone. The morbid conditions of the remaining fibrous structures will be duly noticed, according to their importance, in connection with those organs and apparatus, of which they form either the capsules, the connecting medium, or the fundamental structure.

1. Deficiency And Excess Of Development

Fibrous membranes are completely wanting in all cases in which the organs or apparatus to which they belong do not exist: and, in like manner, a ligament or the tendon of a muscle is sometimes absent altogether. But occasionally there is no actual deficiency of either kind of fibrous structure; it is merely backward in its development, and is thin and weak, and resembles cellular tissue.

When double organs or apparatus exist, the fibrous structures are double too; and accessory ligaments, additional tendons of muscles, etc, afford other instances of plurality in this system. Moreover, there are many circumstances under which fibrous structures are developed in unnatural situations; of which we find instances in the new articular capsules of false joints; in the thick dense plates, the tough bands, and the firm, rounded or branched, callous masses of fibroid tissue into which products of inflammation and coagulable lymph are converted, when they are effused upon serous and synovial membranes, upon the internal coat of the vessels, or within parenchymatous tissues; in cicatrices generally; in the anomalous callus of bone; in the abnormal synchondroses formed after fractures; and lastly, in the fibroid tissue which composes the walls of cysts and cystoid growths.

2. Anomalies In Size And Form

Congenital anomalies of size are presented both by fasciae and ligaments, the former being unnaturally contracted, the latter too short: and in the instance of ligaments, it may happen that one or all of the ligaments of a joint are shorter than natural. Sometimes the shortening of ligaments or tendons is brought on after birth by some loss of substance, or want of extending power, or by a change in their texture.

At any period of foetal, or of subsequent life, fibrous membranes may become enlarged; and this will occur, whatever be the cause of the distension or swelling of the cavities or organs they enclose; thus the sclerotica, the fibrous capsule of a joint, etc, may be found enlarged. Sometimes the membrane becomes proportionally thinner; at other times it increases in thickness and is hypertrophied, just as is the case, under similar circumstances, with the capsule and fibrous structure of certain parenchymatous organs, of which the chronic enlargements of the spleen are an example.

Moreover, the ligaments of joints are liable to relaxation if they be immoderately stretched for some time: and in paralyzed limbs they lose their tone, and elongate.

Fibrous membranes sometimes yield only in one direction; thus in hernia cerebri the dura mater expands only where there are apertures in the skull.

The anomalies of form are merely such as may be deduced from what has been said already, or such as consist of a few rare varieties in the shape of ligaments; any of which may be fissured or subdivided.

3. Anomalies Of Consistence And Continuity

With the exception of a somewhat looser or closer texture of the ligaments, no alterations take place in the consistence of fibrous structures, which are not consequences of palpable disease of texture.

Amongst the solutions of continuity, those lacerations of ligaments and tendons are worthy of remark which are produced by external force and by excessive muscular action: they are more likely to happen if the tissue of these parts have been previously softened by inflammation; when indeed they may occur upon the slightest movements.

Fibrous membranes may be ruptured by excessive distension of the cavities which they enclose, or by immoderate congestion of a parenchyma contained within them, such for example as the spleen; and the same accident may result from their being struck or crushed. Concussion and contusion also sometimes lead to serious consequences when they separate periosteum, or the dura mater, from bone, as they give rise to hemorrhage into the interspace, and subsequently to inflammation and the effusion of a sanious product, as well as to necrosis.

Incised wounds of fibrous structures, especially of tendons, readily heal, as recent experience proves. An exudation from the wounded tendon and other injured parts fills the space which is left between the surfaces of the wound by the retraction of the muscle, and at first unites together all the neighboring structures that take part in the reactionary process; but afterwards it gradually becomes isolated, and new fibrous tissue is formed within it. Losses of substance are repaired in the same way, not only those which have been produced by external violence, but such also as have been caused by an ulcerative process. This fact may be observed in periosteum, or in the dura mater.

4. Deviations From Natural Texture