Why are the interactions of hormones and tissues in the menstrual cycle considered mechanisms?

The interactions of hormones and tissues in the menstrual cycle are considered mechanisms because they involve complex biochemical processes that regulate reproductive functions. Hormones like estrogen and progesterone interact with specific receptors in target tissues, leading to changes in gene expression and cellular activity. These interactions drive the cyclical changes in the ovaries and uterus, coordinating events such as ovulation and the menstrual phase. This system exemplifies a feedback mechanism, where hormonal levels influence and are influenced by physiological responses, ensuring proper reproductive health.