ARTICULA TIONS. LIGAMENTS. 43 7 



Give tlic attachments of the internal lateral ligament of the radio-carpal articu- 

 lation. 



Its apex is attached to the styloid process of the ulna ; its base to the pisi- 

 form and cuneiform bones, and to the anterior annular ligament. 



Give attachments of the external lateral ligament of the radio-carpal articulation. 



Its apex is attached to the apex of the radial styloid process ; its base to the 

 scaphoid and trapezium. 



Give the attachments of the anterior radio-carpal ligament. 



It is attached above to the radius and anterior radio-ulnar ligament ; below, 

 to the two rows of carpal bones. 



Give the attachments of the posterior radio-carpal ligament. 



It is attached above to radius, styloid, and fibre-cartilage ; below, to the first 

 row of carpal bones. 



Does the synovial cavity of the radio-carpal articulation communicate with the in- 

 ferior radio-ulnar or carpal articulations ? 



No. 



CARPAL ARTICULATIONS. 



How may we consider the carpal articulations ? 



(i) The joints of the first row consisting of four short bones ; (2) the joints 

 of the second row consisting of four short bones; (3) the junction of the two 

 rows called the medio-carpal joint. 



Name the short bones in the first and second rows. 



The scaphoid, semilunar, cuneiform, and pisiform ; trapezium, trapezoid, os 

 magnum, and unciform. 



Name the ligaments of the first row. 



They are all connected by two dorsal and two palmar and two interosseous 

 ligaments to each other, except the pisiform. 



How may the pisiform bone be regarded ? 



It may be regarded as a sesamoid bone developed in the tendon of the flexor 

 carpi ulnaris, and connected by a capsule to the cuneiform bone. 



How are the bones of the second row united ? 



By three dorsal, three palmar, and two interosseous ligaments. The articu- 

 lations of the first and second rows belong to the diarthrodial class and arthrodial 

 subdivision of joints. 



Name the ligaments of the medio-carpal articulation. 



These are the anterior, posterior, medio-carpal, and transverse dorsal ligaments. 

 To dissect this region cut through dorsal ligaments. 



Give the attachments of the anterior annular ligament. 



Internally it is attached to the unciform process of the unciform bone, and the 

 pisiform bone ; externally, to the scaphoid and trapezium. 



How many insertions has the flexor carpi ulnaris ? 



Three : (i) Into the pisiform bone ; (2) into the unciform process of the unci- 

 form bone ; (3) into the base of the fifth metacarpal. 



Trace the tendon of the flexor carpi radialis to its insertion. 



It passes through a groove in the os trapezium, and is inserted into the base 

 of the second metacarpal, sometimes also into the third as well. 



How are the carpo-metacarpal articulations classified ? 



(i) Into an outer, corresponding to the thumb ; (2) four inner, corresponding 

 to the remaining four digits. 



Wliv are they so classified .' 



Because they belong to different subdivisions of the class diarthrosis. The 

 carpo-metacarpal of the thumb is a saddle-shaped arthrodia ; the others are simply 

 arthrodia. 



