Shaft and distal end of tibia
The shaft of tibia is triangular in cross-section and has anterior, interosseous, and medial borders and medial, lateral, and posterior surfaces (Fig. 6.80):
- the anterior and medial borders, and the entire medial surface are subcutaneous and easily palpable;
- the interosseous border of the tibia is connected, by the interosseous membrane, along its length to the interosseous border of the fibula;
- the posterior surface is marked by an oblique line (the soleal line).
The shaft of the tibia expands at both the upper and lower ends to support the body's weight at the knee and ankle joints.
The distal end of the tibia is shaped like a rectangular box with a bony protuberance on the medial side (the medial malleolus; Fig. 6.80). The upper part of the box is continuous with the shaft of the tibia while the lower surface and the medial malleolus articulate with one of the tarsal bones (talus) to form a large part of the ankle joint.
The posterior surface of the box-like distal end of the tibia is marked by a vertical groove, which continues inferiorly and medially onto the posterior surface of the medial malleolus. The groove is for the tendon of the tibialis posterior muscle.
The lateral surface of the distal end of the tibia is occupied by a deep triangular notch (the fibular notch), to which the distal head of the fibula is anchored by a thickened part of the interosseous membrane.
Tuesday, November 16, 2010
I'm sitting here on a rainy day trying to slog through Gray's again. You know, I'm pretty good at getting myself enthusiastic about learning just about anything. Anatomy is important, so you'd think I wouldn't have too hard a time mustering up that energy. But it's hard... really hard. And the returns are so low. For those who've never read an anatomy text before, I'm giving you a little present below. : )