482 
MUSCLES OF THE HAND. 
straightened by others that lie along its back. These termi¬ 
nate in long tendons, which are bound down at the wrist by 
a fibrous band that stretches between the bony projections on 
either side, and is termed 
the annular (or ring-like) 
ligament (fig. 228). The 
tendons then spread asunder 
in the hand, and pass-on to 
be inserted into the bones 
of the several fingers, being 
reinforced by a set of small 
muscles that arise from the 
hand itself. 
642. When we consider 
the superior extremity of 
Man as a whole, we remark 
that the several levers which 
are joined end-to-end to form 
it, diminish progressively in 
length. Thus the arm is 
longer than the fore-arm; 
the latter is longer than the 
wrist; and each of the pha¬ 
langes is longer than the 
one which succeeds it. The 
purpose of this arrangement 
is very evident. The nume¬ 
rous joints, in the neighbour¬ 
hood of each other, which 
we see towards the extremity 
of the limb, permit its several 
portions to change their place 
in various ways, so as to ac¬ 
commodate themselves to 
the form of the body which 
it is desired to grasp; whilst the long levers formed by the 
arm and fore-arm, allow the place of the entire hand to be 
rapidly changed to a considerable extent. It is principally 
by the movements of the humerus upon the scapula, that 
the direction of the limb is given; the bending or straight¬ 
ening of the limb regulates its length; whilst the move- 
Fig. 228.— Muscles of the Palm of the 
Hand (Superficial Layer) 
1, anterior annular ligament of the carpus; 
2, 2, extremities of the short abductor of 
the thumb, the intermediate body of the 
muscle having been removed; 3, opposing 
muscle of the thumb; 4, short flexor of 
the thumb; 5, adductor of the thumb; 6, 
lower border of the same muscle; 7 , 7 , 
lumbricales; 8, one of the tendons of the 
deep flexor of the fingers, passing-on to 
insert itself in the bone of the third pha¬ 
lanx, after perforating the tendon of the 
superficial flexor; 9, tendon of the long 
flexor of the thumb; 10, adductor of the 
little finger; 11, short flexor of the little 
finger; 12, pisiform bone; 13, first dorsal 
interosseous muscle. 
