500 



CAVITY. 



sent, finds its way into the synovial sac, and ex- 

 cites inflammation there. 



The disease of the bone commonly giving 

 rise to this ulcer is the slow strumous affection 

 of the spongy extremities, so accurately de- 

 scribed by Sir B. Brodie, the symptoms of 

 which are familiar to every surgeon. A more 

 acute inflammation of the osseous tissue is oc- 

 casionally to be seen, and may be followed by a 

 disease of the same nature, or differing only in 

 the quickness of the course it pursues. 



(t>) Secondary inflammation extending from 

 the synovial membrane is most apt to attack 

 the edges of the cartilages in the first instance. 

 These are thinned, as if abraded, and over- 

 lapped by the vascular or disorganized mem- 

 brane. The bone remains sound, as in the 

 primary ulceration. For further particulars on 

 the ulceration of cartilage, see JOINT. 



Does fractured cartilage ever unite by cartilage ? 

 It probably never does. The costal cartilages, 

 when broken, unite by lymph, which soon after 

 is converted in bone, but never appears to form 

 true cartilage. When a fracture extends into a 

 joint, as we often see in the condyles of the 

 humerus and femur, the divided cartilage is 

 united by a cicatrix, which is not truly car- 

 tilaginous. Neither does it appear that car- 

 tilage is ever regenerated. Laennec believed it 

 was: " in examining a knee-joint, he found in 

 the centre of the articulating surfaces, in place 

 of the natural cartilage, a thin cartilaginous 

 lamina, semi transparent, adherent to the bone; 

 the old cartilage formed around it a projecting 

 border, as if fimbriated."* 



This observation certainly was not enough to 

 establish its power of regeneration. We often 

 find in cases of gout and rheumatism, and 

 especially in the disease designated morbus coxa 

 senilis, that the cartilage is removed, and in its 

 place a compact shining layer of osseous sub- 

 stance like ivory deposited. This is not owing to 

 an ossification of the cartilage, for the cartilage is 

 often found completely absorbed, and the rough 

 bone exposed, which, if seen at a later period, 

 would doubtless be covered with this deposit to 

 prevent the disintegration of its cancellated 

 structure. 



BIBLIOGRAPHY Hunter on the structure and 

 diseases of articulating cartilages, Philos. Trans. 

 1743. Haase, De fabrica cartilaginum, 4to. Lips. 

 1767. Authenrieth, De gravioribus quibusdam 

 cartilaginum mutationibus, 8vo. Tubing. 1798. 

 Mayo, Acute form of ulceration of the cartilages 

 of joints, Medico-Chirurg. Trans, vol. xi. Cru- 

 veilhier, Obs. sur les cartilages diarthrodiaux, et 

 les^ maladies des articulations, Archives Gen. de 

 Med. t. iv. 1824 ; Ej. Usure des cartilages articu- 

 laires, Nouv. Biblioth. Med. t. i. Observations 

 on accidental or loose cartilages may be found, by 

 Cruikshank, in Med. and Philos. Co'mm. of Edinb. 

 vol. iv. ; by Coley, in Med.-Chir. Trans vol. v. 

 by Hor-ne, in Trans, of a Society for Improv. Med. 

 and Chirurg. Knowledge, vol. i. ; by Desault, in 

 his Journ. de Chirurg. t. ii. ; by Abernethy, in his 

 Surg. Observations ; by Laennec, in the art. Car- 

 tilages .Accidentels of the Diet, des Sc. Med. by 

 Cruveilhier, in Nouv. Bib. Med. t. i. 1827 ; '&c. 

 And remarks on special forms of disease affecting 

 the cartilages occur in the general treatises on dis- 



* Op. cit. p. 240. 



eases of the joints, as those of Cooper, Brodie, 

 Schreger, Wilson, and Scott. Vide Bibliography of 

 ARTICULATION. 



(Charles Benson.} 



CAVITY, in anatomy, (cavitas; Fr.cavite; 

 Germ. Hohle; Ital. cavita.} This term is used, 

 in anatomy, to signify any excavation or even 

 depression of more than ordinary depth, which 

 may exist in or between solid parts. Hence 

 we find cavities existing in bones, or formed 

 by the junction of one or more bones, which, as 

 they are severally destined for articulation with 

 other bones, or for the reception or transmis- 

 sion of certain tendons, vessels, &c. are de- 

 signated articular or non-articular. (See BONE.) 



But we have likewise large excavations whose 

 walls are of a more complicated arrangement, 

 and which are destined to receive and protect 

 those organs which are concerned in the func- 

 tions of innervation, respiration, and digestion, 

 and throughout a large proportion of the classes 

 composing the animal kingdom are three in 

 number, namely, the CEPHALIC or CRANIAL 

 cavity, containing the brain the THORACIC 

 cavity, containing the organs of respiration 

 and the ABDOMINAL cavity, containing the 

 organs of digestion and of the secretion of 

 urine. To this last is appended, as a continua- 

 tion, the PELVIC cavity, which is chiefly de- 

 voted to the organs of generation, as well as to 

 some of those connected with the urinary ex- 

 cretion. We refer for particulars connected 

 with the other cavities to the articles CRANIUM, 

 THORAX, and PELVIS, and proceed to consider 

 succinctly the anatomy of the ABDOMINAL 

 CAVITY in its Normal as well as Abnormal 

 conditions.* 



ABDOMINAL CAVITY, (in human anatomy.) 



The annexed woodcut exhibits a vertical 

 section of the body intended to show the tho- 

 racic and abdominal cavities, from which the 

 viscera have been removed. A simple reference 

 to it and to Jig. 204 will sufficiently explain the 

 form and boundaries of the latter cavity, which 

 have been already fully described in the article 

 ABDOMEN. Our object in the present article 

 is to examine the abdominal cavity as it is 

 brought under the eye of the anatomist, when 

 its contents have been exposed by removing or 

 cutting through the abdominal parietes. 



' Some anatomists object to the use of the term 

 cavity, because, say they, every hollow in the 

 animal body is full. Such an objection, on the 

 principle of nature's abhorrence of a vacuum, 

 would go to discard the use of the term, even from 

 ordinary discourse. Considering the word in re- 

 ference to its etymology, it is synonymous with 

 excavation, which in no way implies emptiness, 

 and it is in this sense that we must employ it 

 in anatomical description. I apprehend that con- 

 fusion has arisen from employing the same word to 

 denote the excavation bounded by bone or by bone 

 and muscle, in which the viscus or viscera are 

 lodged, and to indicate the bag or sac of the serous 

 membrane by which each of the three great cavi- 

 ties is lined. In this latter sense, the term cavity 

 is certainly not appropriate, at least it may be 

 most advantageously laid aside ; and we can use, 

 without the same risk of confusion, the expression 

 bag or sac of the peritoneum, pleura, &c. 



