262 



OF THE PRIMARY TISSUES OF THE HUMAN BODY. 



Osseous Epiphysis, and that which is to remain as Articular Cartilage ; both 

 are alike cellular ; and the vessels that supply them with nutrient materials 

 penetrate no further than their surfaces. At a subsequent period, however, 

 when the ossification of the epiphysal cartilage is about to commence, vessels 

 are prolonged into it } and a distinct line of demarcation is seen betwixt the 

 vascular portion, which is to be converted into Bone, and the non-vascular part, 

 which is to remain as Cartilage. At this period, the Articular Cartilage is 

 nourished by a plexus of vessels spread over its free surface, beneath its syno- 

 vial membrane (Fig. 54) ; as well as by the vessels, with which it comes into 



Fig. 54. 



Vessels situated between the attached Synovial Membrane, and the Articular Cartilage, at the point where 

 the ligamentum teres is inserted in the head of the os femoris of the human subject, between the third and 

 fourth months of foetal life ; a, the surface of the articular cartilage ; 6, the vessels between the articular 

 cartilage and the synovia! membrane ; c, the surface to which the ligamentum teres was attached ; d, the 

 Tein ; e, the artery. 



contact at its attached extremity. Towards the period of birth, however, the 

 sub-synovial vessels gradually recede from the surface of the articular cartilage ; 

 and at adult age they have entirely left it, though they still form a band, the 

 " circulus articuli vasculosus," which surrounds its margin. The Fibrous car- 

 tilages are somewhat vascular ; but the vessels do not extend to the cellular 

 portions, where such exist. Neither lymphatics nor nerves can be traced into 

 the substance of Cartilage, which may be affirmed with certainty to be com- 

 pletely insensible, and this in the state of disease as well as of health. 1 The 

 bloodvessels which appear to pass into Cartilages in a state of Inflammation, do 

 not really penetrate its substance, but are limited to the false membrane which 

 is developed de novo, and which not only covers the surface of the cartilage, but 

 also dips down into all the inequalities which are produced by its loss of sub- 

 stance. The usual rate of its nutrition is probably very slow. Its functions, 

 save where it undergoes subsequent transformation, are purely mechanical ; and 

 though it is continually subjected to pressure, yet the extreme smoothness of its 

 surfaces, and their constant lubrication by the synovial fluid, diminish friction 

 so much as to render this a very slight cause of disintegration. It is not at all 

 uncommon, however, for Articular cartilages to be almost entirely destroyed 

 through " anormal nutrition ;" and this without any pain or other symptom to 

 call attention to the change in progress. 2 This process essentially consists in 

 the enlargement of the cartilage-cells, the conversion of their nuclei into a mul- 



1 That the acute pain which so commonly occurs in diseases of joints implicating the 

 Articular Cartilages is not to be referred, as it usually has been, to the cartilage, but to 

 the subjacent bone, has been in the Author's opinion most satisfactorily proved by Dr. 

 Redfern, in his Treatise on "Anormal Nutrition in the Human Articular Cartilages." 



2 See Redfern, Op. cit. 



