32 INTRODUCTION TO SEXUAL PHYSIOLOGY 



The vagina, into which the })eiiis penetrates during coitus, 

 extends from the uterus to the exterior opening. Its walls 

 contain longitudinal and circular muscle fibres, and internally 



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(V A ..•••••~C'.i-.--.-. 



•"■ "^tiw 



■im 



.■jr*^-^:" 



■)it>- 



Fig. 21.— Section tlnough wall of vagina (upper part) of monkey. 



a, E])itlielium ; 6, sub-mucous layer ; c, lymphatic gland ; d, nerve ; 



(\ Pacinian body (a sensory end organ) ; _/, fat cells. 



it is lined by a stratified scaly epithelium, often containing a 

 cornified layer. It opens to the exterior between the nymphse, 

 which are the lips closing the aperture, and lie inside the larger 

 lips or labia. 



