WATiiMV IN A NUTSHELL. 



I'.. Amphiarthrosis. 



I. Symphysis, as between bodies of vertebrae ; and the anterior part of 

 the innominata : symphysis pubes. This kind of joint has no synovial membrane. 

 •_'. Syndesmosis, as the inferior tibio-fibular articulation. 

 c. Dlarthrosis. All the diarthrosis or movable joints are represented in 

 the shoulder girdle and the upper extremity. 



1. A.rthrodia (gliding) in the acromio-clavicular-joint. 



2. Enarthrodia, (ball-and-socket) in the shoulder-joint. 

 :;. ( iinglymus (hinge) in the elbow. 



\. Trochoides or Pivet-joint, in the superior radio-ulnar joint. 



5. Condyloid, as the wrist-joint, having all movements except axial 

 rotation. 



6. Reciprocal Reception (saddle shaped-joint) in the carpo-metacarpal 

 joint of the thumb. 



Ligaments take their names from the bones they join, as sterno-clavicu- 

 lar ligamenl which joins the sternum and the clavicle. When it goes across 

 a notch or groove it is called a transverse ligament and when it goes around a 

 joint it is culled a capsular ligament. Ligaments are composed mostly of white 

 fibrous tissue; the ligaments subflava,and the ligamentum nucha' of the lower 

 animals arc yellow elastic tissue. 



Nerves. If a nerve goes to integument it is called ■•cutaneous;"' if it goes 

 to muscles, i1 is called "muscular;" if it goes to muscles and integument, it is 

 called " musculocutaneous. n There are twelve pairs of cranial nerves and 

 thirty-one pair- of spinal nerves. All spinal nerves are compound nerves be- 

 came they have an anterior root which is motor and a posterior root which is 

 sensory. These two roots unite to form the nerve which contain- both motor 

 and sensory fibers. Bach nerve as it leaves the spinal foramen divides into an 

 anterior and posterior branch. 



Principle l. (Plate IV.) Posterior nerve roots are larger than anterior 

 nerve roots, with the single exception of the first cervical. They are from one 

 and one-half to three times as large. 



Principle II. The anterior branches are larger than the posterior branches 

 in all cases except the firsl and second cervical nerves. 



Principle III. The posterior branches divide into an internal and external 

 division in all cases except the firsl cervical, fourth and fifth sacral, and coc- 



■ ! nerve-. 



Principle IV. The anterior branches make the plexuses. 



Principle V. (Plate V) The posterior nerve root has a ganglion upon it 

 which lies in the intervertebral foramen, outside the sac of the dura mater, ex- 

 cept the first one which is not always present, and when present is situated 

 within the dura mater. This one. and the second, are placed on the arches of 

 the vertebra over which the nerves pass. The ganglia of the last four sacral 

 nerves are situated outside the dura mater bu1 in the spinal canal; the coccy- 

 geal ganglion when presenl is within the dura muter. The nervi nervorum are 

 nerve filament^ going to the nerves and the nerve sheaths. 



