ASPHYXIA. 



257 



generally formed partly of bone and t3artly of 

 ligament, and sometimes moves on the pivot, 

 sometimes the pivot moves in it. The motion 

 is evidently confined to rotation, the axis of 

 which is the axis of the pivot. 



In the human subject the best example of 

 this articulation is that between the atlas and 

 odontoid process of the axis or vertebra dentata. 

 The ring is formed by a portion of the anterior 

 arch of the atlas, completed behind by a trans- 

 verse ligament. Here the atlas rotates round 

 the odontoid process, which is the axis of mo- 

 tion. Another example is the superior radio- 

 ulnar articulation : here the ring is formed one- 

 fourth by bone, namely the lesser sigmoid cavity 

 of the ulna, and the remaining three-fourths by 

 the round ligament called the coronary ligament 

 of the radius. In this case there is rotation as 

 perfect as in that just mentioned, but the head 

 of the radius rolls in the ring, and the axis of 

 motion is the axis of the head and neck of the 

 bone. Some anatomists consider this joint a 

 species of ginglymus, which they designate 

 lateral. 



The terms Symphysis, Synchondrosis, Syn- 

 neurosis, Syssarcosis, Meningosis, have been 

 employed by anatomists to designate certain 

 kinds of articulation, chiefly in reference to the 

 nature of the connecting media. Symphysis, 

 although originally employed with great extent 

 of meaning, seems to have been in later days 

 applied exclusively to denote the articulations 

 of the pelvis, which we have classed under 

 Amphiarthrosis. I pass over the other terms, 

 because they ought to be discarded from use, 

 as only tending to encumber a vocabulary 

 already too much crowded with difficult and 

 unnecessary terms. 



The descriptive anatomy of the several joints 

 will be found under the heads ANKLE, CRA- 

 NIUM, ELBOW, FACE, FOOT, HAND, HIP, 

 KNEE, PELVIS, RADIO-ULNAE, SHOULDER, 

 SPINE, TEMPORO- MAXILLARY, TIBIO-FIBU- 

 LAR, WRIST, and the morbid anatomy under 

 the head JOINT. 



BIBLIOGRAPHY. Havers, Osteologia nova, 8vo. 

 Lond.1691. Saltgmann, De Arliculationibits Artuum, 

 Argent. 1712. Walther, De Articulis, Ligaraentis, 

 &c. 4to. Lips. 1728. Neumann, Lehre von d. 

 Articulationen d. mensch. Koerpers, Freiberg, 1745. 

 Isenftamm, Diss. de Ginglymo, 4to. Erlang. 1785. 

 Bonn, De Suturarum coip. hum. fab. et usu, Lips. 

 1763. Hause, De unguine articular! ejusque vitiis, 

 4to. Lips. 1774 ; Ej. De fabrica cartilaginum, 4to. 

 Lips. 1767. Petschel, De Axungia articulari, Lips. 

 1740 (Recus. in Halleri Diss. Anat. select.). Weit- 

 brecht, Syiidesmologia, 4to. Petrop. 1742 (decidedly 

 the best work extant on the descriptive anatomy of 

 the ligaments). Hunter, W. on the structure and 

 diseases of articulating cartilages, Philos. Trans. 

 1743. Schaarschmidt , Syndesmologische Tabellen, 

 8vo. Lange. 1782. Monro on the Bursae mucosae, 

 fol. Edinb. 1788. Heysigers, Diss. Phys. Anat. 

 de fabrica intima articulationum, 8vo. Traj. ad 

 Rhcn. 1803. L'oschye, Die Knochen, &c. des 

 mensch. Koerp. fol. Erlang. 1804. Bichat, Mem. 

 sur la membrane synoviale des articulations, Mem. 

 de la Soc. Philom. An. 6. Dickinson, A syndes- 

 mological chart, 8vo. Lond. 1821. Cooper, B. on 

 the ligaments, 4to. Lond. 1825. Cruveilhier, Sur 

 les cartilages diarthrodiaux, Arch. Gen. de Med. 

 Fevrier, 1824. Bichat, Anatomie generale. Beclard, 

 Anatomic generale. (The older and likewise the 



VOL. I. 



newer systems of anatomy are mostly deficient in 

 syndesmology ; the works of Bichat and Boyer, 

 however, form exceptions, and are well deserving 

 of a careful perusal : the descriptions in the Traite 

 des Maladies Chirurgicales, t. iv. of the latter, are 

 also very excellent ; and one of the most minute 

 and accurate accounts we have of the ligaments is 

 contained in the magnificent work of Messrs. 

 Bourgery and Jacob, now in the course of publica- 

 tion : Traite complet de 1'anatomie de 1'homme ; 

 Anglice, The whole anatomy of the human body, 

 by R. Willis, fol. Paris and Lond.) 



( R. B. Todd.) 



ASPHYXIA. (Gr. ArQv^a. Fr. Asphixie. 

 Ger. Sckeintodj Aspfiyxie. Ital. Asfissiaf) The 

 word Asphyxia, according to its derivation 

 (from a and <7<pvfj, pulsus,) ought to signify 

 what is usually expressed by the term Syncope, 

 i. e. failure of the heart's action ; but it is now 

 always used to express failure of the process 

 of respiration. 



It is hardly necessary to say, that there is 

 no more general law of vital action, in all 

 classes of organized beings, than its dependence 

 on oxygen, i. e. on a certain chemical action 

 taking place between the nourishing fluids of 

 that living body (whether animal or vegetable) 

 and the oxygen of the atmosphere. This law 

 is, indeed, as general as the dependence of 

 vital action on heat, and in like manner as a 

 certain elevation of temperature (short of what 

 acts chemically on the organized textures) is 

 destructive to life, so a certain concentration 

 of oxygen in the air inhaled, at least by the 

 higher orders of animals, affects them as a 

 poison.* 



Many organized substances, as the seeds, 

 roots, and stems of vegetables, the pupae of 

 insects, eggs, even perfect animals of some of 

 the lower classes, may retain their vitality, 

 as is commonly said, i. e. remain susceptible of 

 vital action, for very various periods of time, 

 at low temperatures, without exercising any 

 action on the oxygen of the atmosphere ; but 

 whenever the phenomena indicating vital ac- 

 tion take place in them, exposure to oxygen, 

 and a certain alteration of the air surrounding 

 them, very soon become necessary conditions 

 of the continuance of vitality. 



The alterations which take place in the air 

 in contact with different living bodies are some- 

 what various. Water is exhaled probably in 

 eveiy instance. In the case of some animals, 

 particularly fishes, there is certainly an absorp- 

 tion of azote ; and in that of vegetables growing 

 under the influence of light, there is a decided 

 absorption of carbon from the carbonic acid 

 of the atmosphere, and an evolution of pure 

 oxygen. But it is now generally agreed, that, 

 in all cases, the action between the atmosphere 

 and the nourishing fluid which is essential to 

 the motion and vivifying power of the latter, 

 is that which is denoted by the disappearance 

 of part of the oxygen from the air that comes 

 in contact with that fluid, and the substitution 

 of a quantity of carbonic acid. 



Some time since it was the prevalent opinion, 

 that the nature of that action was merely an 



* See Broughton in Journal of Science, 1830. 



S 



