The female menstrual cycle is something that all women usually live with every month, where we experience emotional and physical changes from a hormone pump. All this to prepare the body for a possible pregnancy. Though that's the purpose of the cycle, we'll focus our attention on knowing what's going on.
The menstrual cycle has an average duration of 28 days, but the time between each cycle can vary. As we've mentioned in previous articles, each body is a different world, ranging from 21 to 35 days.
Its onset occurs on the first day of menstrual bleeding and ends until a new bleed recurrence. There are different phases within the cycle, which we will mention and explain below.
If you want to understand better, you can check the article on the female reproductive system.
The Phases
Menstruation
in this phase, the endometrium (the most superficial layer of the uterus) has progressively increased in size to generate an optimal environment for the implantation of a fertilized egg. If fertilization is not given, i.e., there is no clutch, the endometrium is released, generating bleeding. Menstrual bleeding usually lasts 3-7 days. In addition to this, it is possible to experience the famous menstrual cramps resulting from the endometrium's contractions expelled from the uterus.
Follicular phase
The phase in which the pituitary gland (a gland located in the brain) sends signals to the ovaries through the Follicle Stimulating Hormone responsible for the maturation of the follicles. So, what are these follicles? They are small baskets located inside the ovary, responsible for storing the eggs in an immature state. During maturation, there is estrogen release. This estrogen will travel through the blood until it reaches the endometrium and initiates the layer's growth.
Ovulation phase
Ovulation is generated by the release of LH (Luteinizing Hormone), causing the dominant follicle to break and release the egg. This egg will travel through the fallopian tubes, where sperm is expected for fertilization. Although day 14 is the most fertile, days 11 to 16 are abundant, as well, because of the life span of sperm within the female reproductive system, which is 72 hours (3 days). If you had sex on the 11th day from the beginning of the menstrual cycle, the sperm could fertilize on the 14th as it lives 3 days, as mentioned above.
Lutheal phase
This phase gives poster start to ovulation, with a duration of 14 days. After the release of the egg through the follicle, it becomes a luteal or yellow body. This is the degradation of the east follicle and initiates progesterone release (a hormone known as pregnancy). If the body does not detect pregnancy, the corpus luteum disappears, generating diminution of estrogens and progesterone, which results in the detachment of the endometrium, and a new cycle starts.
What actually happens in the endometrium?
What happens in the ovaries?
Camila Quintero
Adira advisor, last year medicine student interested in women’s wellness and promoter of a healthy lifestyle. You can find more of her content on @karantina_col where you'll find recipes and tips to a better wellbeing.
Botero Uribe, J., Henao, G., Londoño Cardona, J. and Júbiz, A., 2010. Obstetricia Y Ginecología. 8th ed. [Medellín]: [Corporación para Investigaciones Biológicas], pp.480-482.
https://www.reproduccionasistida.org/fases-del-ciclo-menstrual/cambios-del-endometrio-ciclo-menstrual
https://www.alamy.es/ciclo-ovarico-dibujo-image67527503.html