Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 28 On the Ossicles Which Resemble a Sesame Seed

In the Hand

First, two ossicles (T in figs 1 and 2, ch. 25) 4 are located in the inner surface of the second joint of the thumb, where its first bone is articulated to the second; they are quite round and solid, not differing much in their shape from a grain of rice: they are a little shorter than an actual grain. But as a grain of rice appears depressed on one side, so also is a part of these ossicles depressed, slightly hollowed and coated with cartilage on that part where they are both attached to the first bone of the thumb. They lie on the inside of the head of the first bone [caput ossis metacarpalis I] near the root of the head where it first begins to be covered and smoothed with cartilage [cartilago articularis]; one ossicle occupies the outer side of the inner surface of the head, and the other the inner side of the same surface. Both allow the tendon [m. flexor pollicis longus, tendo] (h and then q in the 6th table of muscles) that flexes the third bone of the thumb to be borne through the interval by which they are separated from each other. Since these ossicles are strongly attached to that bone of the thumb, they are convex on the outside and resemble the part of a bone which puts forth ligaments and receives the insertion of tendons. In just this way two ossicles (V, V in fig. 1, ch. 25) are also found in the first internodes of the other fingers, 5 positioned in the same spot and smaller than the ossicles of the thumb the nearer you approach the little finger. The smallest and more or less cartilaginous ossicles are attached to the first joint of that finger [art. metacarpophalangealis V], or rather to the head of the metacarpal bone that supports the little finger. The remaining fingers are in an intermediate state. In old and (so to speak) bony people I have sometimes seen a single ossicle (corresponding to the one marked * in fig. 2, ch. 33) 6 located on the inner surface of the third joint of the thumb [art. interphalangealis pollicis], placed before the depression (L in fig 2, ch. 27) separating the heads of the second bone [phalanx proximalis] on its inner surface. Such an ossicle (X, X in fig. 1 ch. 25) has sometimes come to my attention in individual second and third finger joints, but so small as scarcely to equal the size of a millet seed. Unless you take the greatest care in cleaning bones, it may be discarded 7 (even as the ones in the first joints) along with the ligaments and never offer itself to view. An ossicle of noteworthy magnitude (N in figs. 1, 2, ch. 25) belonging to this type is generally observed where the metacarpal bone that supports the little finger is articulated to the eighth carpal bone [os hamatum]. This is how it is with the ossicles of the hand.



Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 28 On the Ossicles Which Resemble a Sesame Seed