The wall of the vagina consists of a mucosa, muscularis and fibrosa.
The mucosa is non-glandular and is thrown into folds. It is lined by stratified squamous epithelium. The lamina propria consists of loose connective tissue especially rich in elastic fibres. It contains diffuse infiltration of lymphocytes and solitary lymph nodules may also be present.
The muscularis consists of an inner thicker circular layers and a thin outer longitudinal layer of plain muscle. The fibrosa consists of dense connective tissue with many coarse elastic fibres and contain large blood vessels and nerves. At the anterior part there is serosa which has the usual structure of serous membrane.
The vagina also undergoes structural changes during the various stages of oestrus cycle. The changes are chiefly in the mucosa which increase in thickness and number of layers of the epithelium during proestrus and oestrus. Cornification to varying degrees in different species at oestrus followed by desquamation at metestrus, the epithelium being low in height at diestrus.