Skip to main content
. Author manuscript; available in PMC: 2023 Jan 31.
Published in final edited form as: J Vis Exp. 2021 Aug 30;(174):10.3791/62884. doi: 10.3791/62884

Figure 1: Hormone rhythmicity in estrous cycle stages.

Figure 1:

(A) The varying sex steroid hormone levels during the prominent estrous cycle stages are outlined and summarized. The stage progression begins and ends with metestrus to demonstrate the building hormone levels and the circular progression of the process. Adapted from an external source11. (B) Flow of sex steroid hormones from the central nervous system to the reproductive system via the bloodstream. It is seen that the hormone levels are increased through signals from the hypothalamus and pituitary gland via gonadotropin-releasing hormone (GrH or LHRH) and the combination of follicle-stimulating hormone and luteinizing hormone, respectively. This includes both positive and negative feedback loops depending on the concentration of estradiol and progesterone. Information17 and images traced from external sources65, 66, 67. Abbreviation: LHRH = luteinizing hormone-releasing hormone. Please click here to view a larger version of this figure.