Changes

* Outer layer of adventitia

* Outer layer of adventitia

It is not lined by mesothelium and merges with the adventitial layers of the bladder anteriorly and rectum posteriorly. This combination of elastic fibres and [[Muscles_- Anatomy & Physiology#Smooth_Muscle|muscular]] layers allows the massive distension that occurs during parturition.  After [[Copulatory Behaviour - Anatomy & Physiology|coitus]], contraction of the smooth muscle layer ensures that the pool of semen remains within the cervical region. When relaxed, the vaginal wall collapses to obliterate the lumen and the vaginal epithelium is thrown into folds. The dense lamina propria is aglandular and contains:

It is not lined by mesothelium and merges with the adventitial layers of the bladder anteriorly and rectum posteriorly. This combination of elastic fibres and [[Muscles_- Anatomy & Physiology#Smooth_Muscle|muscular]] layers allows the massive distension that occurs during parturition.  After [[Copulatory Behaviour - Anatomy & Physiology|coitus]], contraction of the smooth muscle layer ensures that the pool of semen remains within the cervical region. When relaxed, the vaginal wall collapses to obliterate the lumen and the vaginal epithelium is thrown into folds. The dense lamina propria is aglandular and contains:

** Elastic fibres

* Elastic fibres

** Rich plexus of small veins

* Rich plexus of small veins