Final answer:
Cervical fluid changes throughout the menstrual cycle in response to hormone levels, becoming more sperm-friendly around ovulation and thicker post-ovulation if no fertilization occurs.
Step-by-step explanation:
Cervical fluid, also known as cervical mucus, is a vaginal secretion produced by the cervix. Throughout the menstrual cycle, the consistency and quantity of cervical fluid change due to fluctuating hormone levels. These changes serve to either facilitate or inhibit sperm movement and survival, playing a crucial role in the process of fertilization.
During the menstrual cycle, several phases occur:
- The menstrual phase, which is the shedding of the uterine lining when pregnancy does not occur.
- The follicular phase, during which time the ovarian follicles mature and estrogen levels rise, leading to a thinner and more hospitable cervical fluid for sperm.
- Ovulation, marked by a spike in luteinizing hormone (LH), results in the release of an egg and the production of cervical fluid that is most conducive to sperm movement.
- The luteal phase, post-ovulation, when the cervical fluid becomes thicker and more restrictive as progesterone levels rise, aiming to preserve the optimal conditions in the uterus in case of a potential pregnancy.
If fertilization does not occur, the cycle repeats, starting with the menstrual phase.