HUMAN PHYSIOLOGY 

 best marked of these are the reflex acts of micturition 



External rotators of hij>. 

 Hamstrings. 



Calf muscles and extrinsic muscles 

 of foot. 



Intrinsic muscles of foot. 



Muscles of bladder and urethra. 

 Extrinsic muscles of foot. 

 Intrinsic muscles of foot. 



Levator and sphincter ani. 



FIG. 79. The Groups of Cells in the Anterior Horn of grey matter at the level 

 of the second, third, and fourth Sacral Nerves. (From BRUCE.) 



(p. 407), defaecation (p. 355), erection, and ejaculation 



./VVVVVA/SAAAAAAAAA/* T. 



FIG. 80. The neuro-iuuscular mechanism concerned in the knee jerk. 

 and the time of the knee jerk (A.J.) compared with the time 

 of a reflex action (4.72.). 



(p. 415). The lumbar enlargement is the part of the cord 

 involved. 



