THE VAGINA. 



405 



THE VAGINA. 



The vagina is a curved cylindrical canal which ex- 

 tends from the vulva to the uterus. It is about four 

 inches along the anterior and six inches along the pos- 

 terior wall, and. is attached above to the cervix uteri. 

 Its orifice is the most constricted portion. It presents 

 three coats, erectile, muscular, and mucous. The 



FIG. 178. NATURAL POSITION OF THE PELVIC ORGANS, WITH FULL BLADDER. 



erectile coat consists of an abundant venous plexus, 

 supported by connective tissue. The muscular coat has 

 an outer circular and an inner, thick, longitudinal layer 

 of fibres. The mucous membrane is loosely attached to 

 the muscular coat, presents anteriorly and posteriorly a 

 vertical column, from which pass off numerous transverse 

 rugae. They are all obliterated when the organ is dis- 

 tended. The epithelium of the vagina is of the squa- 



