Menstrual Cycle Overview and Anatomy

Menstrual Cycle Overview

• Average cycle length is approximately 28 days
• Ovulation typically occurs around day 14
• Cells multiply to create a corpus luteum during the luteal phase

Endometrial Regeneration

• The proliferative phase is the phase of endometrial regeneration
• This phase lasts until the luteinization of the Graafian follicle occurs around ovulation

Ovarian Hormones

• Two key hormones are estrogen and progesterone
• Estrogen is secreted by the follicles
• Progesterone is secreted by the corpus luteum

Menstrual Phase

• The menstrual phase lasts approximately 1 to 5 days
• Progesterone levels decline during this phase
• Spiral arterioles constrict

Endometrial Appearance

• The endometrium appears hypoechoic during the proliferative phase with a three-line sign.

Irregular Menstrual Cycles

• Polymenorrhea is when the menstrual cycle occurs more frequently than every 21 days

Anatomical Structures

• The pouch of Douglas is also known as the rectouterine pouch

Phases of Menstrual Cycle

• The secretory phase occurs from days 15 to 28 of the menstrual cycle

• The secretory phase corresponds to the luteal phase of the ovarian cycle.

• The proliferative phase occurs from days 5 to 14 and corresponds to the follicular phase of the ovarian cycle.