Volume 1

On the anatomy, physiology, and pathology of the chimpanzee / by Charles F. Sonntag.

  • Sonntag, Charles F. (Charles Frederick), -1925
Date:
1923
Catalogue details

Licence: In copyright

Credit: On the anatomy, physiology, and pathology of the chimpanzee / by Charles F. Sonntag. Source: Wellcome Collection.

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    sheath almost to its insertion; but the deep belly loses its sheath on the dorsum of the foot, and is separated from the cuneiform bone by a bursa. The extensor longus digitorum arises from the external condyle of the tibia internal to the head of the fibula, the anterior border of the head of the fibula, the antero-medial surface of the fibula to within an inch of the malleolus, the anterior peroneal inter- muscular septum to the same level, the fascia between it and the tibialis anticus and the fascia over its upper half. The belly passes through the lateral compartment under the annular ligament, and divides into four slips. The second slip is thready, but the others are well developed. The first slip divides into two ; the medial one going to the dorsum of the second toe, and the lateral one joins the second slip and runs to the third toe. The third and fourth slips run to the fourth and fifth toes. The slips form dorsal expansions over the metacarpo-plialangeal joints and proximal phalanges, which are joined by the lumbricales, interossei, and extensor brevis, except in the case of the fifth toe. The actual insertions into the bones are as in Man. The extensor longus hallucis arises from the middle third of the antero-medial surface of the shaft of the fibula, and from the outer part of the interosseous membrane, posterior to the extensor digitorum longus. The belly passes through the middle com- partment under the anterior annular ligament, and continues as a tendon round the inner surface of the entocuneiform. It runs through the naviculo-metatarsal trochlea (text-fig. 36 B) and reaches the dorsum of the metatarsal of the hallux. A dorsal expansion is formed over the first phalanx, the proximo-lateral part of which joins the tendon of insertion of the most medial tendon of the extensor brevis digitorum. The rest of the tendon has an expanded insertion into the base of the terminal phalanx of the hallux and the capsule of the interphalangeal joint. The peroneus tertius is absent. The gastrocnemius has two heads, but they arise more pos- teriorly and distally than in Man, and from the capsule of the knee joint instead of from bones. They spring from the capsule over the articular surface. They are inserted into a median tendinous raphe, the inner belly slightly overlapping the external, and extending more laterally. The flattened tendon joins the tendon of the soleus, half an inch above its insertion into the calcaneus, forming the tendo Achillis. The edges of the muscle are firmly connected to the subjacent soleus. The plantaris arises lower down than in Man, from the postero- lateral side of the external femoral condyle. The slender belly, three inches long, passes under the lateral belly of the gastro- cnemius, and the very fine thread-like tendon has an expanded insertion into the tendo Achillis close to the calcaneus. The soleus has no tibial origin, and is smaller than in Man. It has a fleshy origin from the posterior aspect of the head of the fibula, and an aponeurotic origin from the upper part of the 24* [37]
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