PLANTAR REGION. 



259 



The DORSAL INTEROSSEI muscles are placed between the metatarsal 

 oones ; they resemble the analogous muscles in the hand in arising by 

 two heads from the adjacent sides of the metatarsal bones ; their tendons 

 are inserted into the base of the first phalanx, and into the digital expan- 

 sion of the tendons of the long extensor. 



The first dorsal interosseous is inserted into the inner side of the second 

 toe, and is therefore an adductor ; the other three are inserted into the 

 outer side of the second, third, and fourth toes, and are consequently 

 abductors. 



Relations. By their upper surface with a strong fascia which separates 

 them from the extensor tendons. By their under surface with the plantar 

 interossei. Each of the muscles gives passage to a smajl artery (posterior 

 perforating) which communicates with the external plantar artery. And 

 between the heads of the first interosseous muscle the communicating 

 artery of the dorsalis pedis takes its course. 



Fig. 135* 



Fig. 136.f 



Plantar Region. 



First Layer. 

 Abductor pollicis, 

 Abductor minimi digiti, 

 Flexor brevis digitorum. 



Dissection. The sole of the foot is best dissected by carrying an inci- 

 sion around the heel, and along the inner and outer borders of the foot, to 



* Dorsal interossei. 1. Abductor secundi. 2. Adductor secundi. 3. Adductor tertn. 



4. Adductor quarti. 



-f- The first layer of muscles in the sole of the foot ; this layer is exposed by the re- 

 moval of the plantar fascia. 1. The os calcis. 2. The posterior part of the plantar 

 fascia divided transversely. 3. The abductor pollicis. 4. The abductor minimi digiti. 



5. The flexor brevis digitorum. 6. The tendon of the flexor longus pollicis muscle. 

 7, 7. The lumbricales. On the second and third toes, the tendons of the flexor longns 

 digitorum are seen passing through the bifurcation of the tendons of the flexor brevis 

 digitorum. 



