AND PHYSIOLOGY. 



1Z 



ments which unite the lower 

 end of the fibula to the tibia 

 and the tarsal bones, and in 

 Fig. 93 the ligaments of the 

 foot. 



163. Synovial Membrane 

 and its Secretion. — The 

 lubrication of the joints is 

 effected by means of a thin 

 membrane lining their cavi- 

 ties which secretes an oily 

 substance called the Synovia, 

 (Fig. 94, p. 74), that is con- 

 stantly applied to the oppos- 

 ing surfaces. In health the 

 action of the joint stimulates 

 this membrane to the secre- 

 tion of a proper amount of 



Fig. 93. 



A Vertical Section of the Ankle-Joint and Foot of the Eight Side. 1, The Tibia. 

 2, The Astragalus. 3, Os Calcis. 4, The Scaphoides. 5, The Cuneiforme Internum. 

 6, The Metatarsal Bone of the Great Toe. 7, The First Phalanx of the Great Too. 

 8, The Second Phalanx of the Great Toe. 9, The Articular Cavity between the Tibia 

 and Astragalus, with its Articular Adipose Matter. 10, The Synovial Capsule between 

 the Astragalus and Calcis. 11, The Calcaneo-Astragalian Interosseous Ligament. 

 12, The Synovial Capsule between the Astragalus and Scaphoides. 13, The Calcaneo- 

 Scaphoid Ligament. 14, The Calcaneo-Cuboid Ligament. 15, The Synovial Capsule 

 between the Scaphoides and Cuneiforme Internum. 16, The Synovial Capsule between 

 the Cuneiforme Internum and the First Metatarsal Bone. 17, The Metatarso-Pha* 

 langial Articulation of the Great Toe, with the Sesamoid Bones below. 18% The- Pha- 

 langial Articulation of the Great Toe. 



A Posterior View of the Ankle-Joint of 

 the'Left Side. 1, The Interosseous Liga- 

 ment of the Bones of the Leg. 2, The 

 Posterior Inferior Ligament connecting 

 the Tibia and Fibula. 3, The Transverse, 

 or Long Fibres of the same Ligament 

 4, The Internal Lateral Ligament. 5, Tho 

 Posterior Fasciculus of the External Lat- 

 eral Ligament. 6, The Middle Fasciciu 

 lus of the same. 7, The Synovial Capsule 

 8, The Os Calcis. 



