Sperm in the Female Tract - Anatomy & Physiology

()Map REPRODUCTIVE SYSTEM (Map) FERTILISATION , IMPLANTATION AND EARLY EMBRYONIC DEVELOPMENT'

Overview

• There is immediate retrograde loss at the entrance to the cervix/uterus with phagocytosis by leukocytes.
• In the cervix, sperm must travel through privileged pathways. This serves to eliminate non-motile sprem and remove some abnormalities.
• In the Uterus, capacitation is initiated with some phagocytosis occuring.
• In the Oviduct, capacitation is completed and sperm show hyperactive motility.
• At the Uterotubal Junction, the acrosome reaction occurs and the spermatozoon penetrated the oocyte in fertilization with the formation of male and female pronuclei.

Privileged Pathways

• Sperm must travel through the highly convoluted cervix.
• During oestrus, the cervix produces mucus.
  • Sialomucin: Low viscosity mucus produced by basal areas of cervical crypts.
  • Sulfomucin: More viscous mucus produced in apical portions of the cervical epithelium covering the tips of cervical folds.
• The difference in viscosity of the mucus creates two distinct environments within the cervix.
• Sperm encountering sulfomucin are washed out of the tract.
• Sperm encountering sialomucin swim into it, creating 'privileged pathways' in deeper cervical crypts. Sperm then traverse the cervix through these pathways.
• Thus, the cervix acts as a filter to immotile sperm because in order to survive; the sperm must actively swim into the 'privileged pathways'.