THE ARTICULATIONS. 68 



Che Fourth, between the trapezium and the metacarpal bone of the thumb. 

 The Fifth, between me cuneiform and pisiform bones. 



Describe the Metacarpo-metacarpal Articulations. The 4 inner meta- 

 jarpal bones are connected together at their bases by Dorsal, Palmar, and 

 Interosseous Ligaments; and at their digital extremities by the Transverse 

 Ligament. 



Describe the remaining Articulations of the Hand. The metacarpo- 

 phalangeal and the phalangeal articulations are all ginglymoid joints, and each 

 has an Anterior and 2 Lateral Ligaments, the former being lined each with a 

 synovial membrane. There are no posterior ligaments to these articulations, 

 the extensor tendons of the hand supplying their places. 



Describe the Hip-joint. It is a true enarthrodial articulation, formed by 

 the head of the femur with the acetabulum of the os innominatum. Its Syno- 

 vial Membrane is extensive, investing most of the head and neck of the femur, 

 the capsular, cotyloid and teres ligaments, and the cavity of the acetabulum. 

 Its Arteries are derived from the obturator, sciatic, internal circumflex, and 

 gluteal. Its Nerves are branches from the sacral plexus, great sciatic, obtu- 

 rator, and accessory obturator. It has 5 ligaments, as follows, viz. 



Capsular, from the margin of the acetabulum and the transverse ligament, 

 into the base of the neck of the femur above, the anterior inter-trochan- 

 teric line in front, and to the middle of the neck of the bone, behind. 

 Ilio-femoral or Y-ligament, from the anterior inferior spine of the ilium, into 

 the anterior inter-trochanteric line by two fasciculi. It is a dissected por- 

 tion of the capsular ligament which is very strong anteriorly. 

 Ligamentum Teres, from a depression on the head of the femur into the 

 margins of the cotyloid notch of the acetabulum and into the transverse 

 ligament, by two fasciculi. 



Cotyloid, a fibro-cartilaginous band surrounding the margin of the acetab- 

 ulum in order to deepen its cavity. 



Transverse, that part of the cotyloid ligament which crosses over the coty- 

 loid notch converting it into a foramen. 



Describe the Knee-joint. It is a ginglymus articulation, formed by the 

 condyles of the femur with the head of the tibia, and the patella in front. Its 

 Synovial Membrane is the largest in the body, being reflected for 2 or 3 

 inches over the anterior surface of the femur, where it is supported by the sub- 

 crureus muscle, also over its condyles, the patella, semilunar cartilages, crucial 

 ligaments, and head of the tibia ; and is prolonged through an opening in the 

 capsular ligament beneath the tendon of the popliteus. Its Arteries are derived 

 from the anastomotica magna, the 5 articular branches of the popliteal, and 

 the recurrent branch of the anterior tibial. Its Nerves are branches of the 



