178 LABORATORY MANUAL OF HUMAN ANATOMY 



(a) Short flexor muscle of the toes (M. flexor digit orum brevis). Exam- 



ine its ligamentous sheath (ligamentum vaginale), annular ligament 

 (ligamentum annular e), and the cruciate ligament (ligamentum 

 cruciatum ) . 



After having made a careful study of this ligamentous sheath, 

 incise it in the medial line and reflect each way, preserving care- 

 fully the vessels and nerves. Note the synovial sheath (vaginae 

 tendinum digitales pedis) surrounding the flexor tendons. (Vide 

 Spalteholz, Fig. 407.) What relations exist between the tendons 

 of the long and of the short flexors of the toes? Compare these 

 relations with those found in the hand. 



(b) Abductor muscle of great toe (M. abductor hallucis}. 



(c) Abductor muscle of little toe (M. abductor minimi digiti). 



Divide these muscles at their origin and reflect them forward. Exercise 

 great care and avoid injury to yessels and nerves immediately beneath. 



Plantar Arteries. (Vide Spalteholz, Fig. 481.) 



Determine the relations of these different arteries. What is 

 the linear guide for each artery ? All the branches are mentioned 

 here, although many will not be seen at this stage of the dis- 

 section. 



(a) Medial plantar artery (A. plantaris medialis) (0. T. internal plan- 



tar). 



(aa) Superficial branch (ramus super ficialis) . 



(ab) Deep branch (ramus profundus). 



(b) Lateral plantar artery (A. plantaris lateralis) (0. T. external plan- 



tar). 

 (ba) Plantar arch (arcus plantaris). 



(baa) Plantar metatarsal arteries (Aa. metatarseae plan- 



tares). 



(bab) Perforating branches (rami perforantes) . 



(bac) Digital plantar arteries (Aa. digitales plantar es). 

 With what arteries do the above anastomose? Dissect out the veins 



accompanying the arteries and trace them into larger stems. 



Plantar Nerves. (Vide Spalteholz, Figs. 824 and 825.) 



Determine what muscle is supplied by each nerve, also the 

 exact cutaneous supply. What is muscle sense! 



(a) Medial plantar nerve (N. plantaris medialis) (0. T. internal plantar). 



(aa) Common digital plantar nerves (Nn. digitales plantar es com- 



munes). 



(ab) Proper digital plantar nerves (Nn. digitales plantar es pro- 



prii). 



(b) Lateral plantar nerve (N. plantaris lateralis) (0. T. external plan- 



tar). 

 (ba) Superficial branch (ramus superficialis) . 



Common digital plantar nerves (Nn. digitales plantar es 

 communes). 



