GENERA] 



tog 



In other cases the discs or menisci are perforated in the mi rcular 



in shape, so that the cartilaginous extremities of the bone are in tily in the mi 



the articulation. The menisci frequentl) serve the pur] 

 or they may a< i as joint cushioi 



The articular margins or glenoidal lips are usually circular conn- rtil- 



aginous structures which are situated upon the marj I the bon) r the 



Increasing it 



The joint cushions, usual! isting of fatty . fill out tl. 



and are for the purpose of breaking the jar of the movements of tl. 



my locking mechanisms limit the movement of a p 

 part striking against a bony projection. 



A joint i iposed of only two bones, in which 



Sometimes, 1 r, three or more bones enter into the formatioi r port! 



socket an- formed of connectivi »mponents 1 which case th 



rmed a compound joint. 



e joints of the human body are sur- 



faces. Tl ibdivisions an Uniaxial 



joints. 



The uniaxial joints are composed of two varieties, those with a tnd th 



with a longitudinal axis ; of motion in the first variety is 



of the moving bone and in the second variety the two ax< 



I. UNIAXIAL JOINTS. 



(a ) With a Transverse Axis. The hinge joint or 1 



joints are broad and the articular surfaces are usually not quite cylindri 

 exhibiting a median excavation and th. ket a 



formation together witl prevents the lateral • 



so that the axis of motion coincides with th. id and 



The motions permitted by a ginglymoid joint an . in 



complete extension the bones form an angle of 180 1 I 



joint are furnished by the interphalangeal joints ^i the finj 



The spiral or coclilear joint forn bvariety of the hin in the 



cylindroid and the elevation in th et form a 



mation, flexion : impanied 1 ertain am. :' lateral .. fur- 



nished by the ankle-joint and by a portion of the t. •! 



b With a Longitudinal Axis. The only 

 joint, also termed a /.; The articulating surf, 



cylinder or cone and the solid cylinder r in a hollow cylin 



superior radio -ulnar articulation and the median articulation oi the atlas and axis a :cal 



examples oi this form of joint. 



