Practice question

After deposition in vagina, sperm translocation through cervix, uterus and into oviduct depends on both autonomous motility and female tract facilitation. Cervical mucus filters immotile sperm, uterine peristaltic contractions propel sperm rapidly toward uterotubal junction, and oviductal ciliary beating generates fluid flow that must be overcome by rheotaxis. Coordinated contractions under oxytocin and prostaglandin influence provide long-distance transport exceeding intrinsic swimming velocity. Subsequent hyperactivated motility within oviductal isthmus enables mucus penetration, ascent toward ampulla where fertilization occurs, embryo begins cleavage and early divisions for transport.