Uterine Menstrual Cycle Stages of the menstrual cycle
- Slides: 8
Uterine (Menstrual) Cycle § Stages of the menstrual cycle § Menstrual phase § Proliferative stage § Secretory stage Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings
Menstrual Cycle: Phase 1 Menstrual phase Days 1– 5 § Outer layer of the endometrium is sloughed § Bleeding occurs for 3– 5 days (female’s “period”) § Low levels of estrogen and progesterone Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings
Menstrual Cycle: Phase 2 Proliferative stage Days 6– 14 (AKA: The follicular phase) § FSH is stimulating the follicle to mature § As the follicle matures it is releasing estrogen § Estrogen is causing the endometrium to thicken § Ovulation occurs at the end of this stage (Day 14) § A surge in LH causes ovulation Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings
Menstrual Cycle: Phase 3 Secretory stage Days 15– 28 (AKA: The luteal phase) § Corpus luteum develops § Corpus luteum releases progesterone § Levels of progesterone increase the blood supply to the endometrium (thickening the lining) Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings
§ Secretory stage (continued) If fertilization does occur § Embryo produces a hormone (HCG) that stops the corpus luteum from disappearing If fertilization does NOT occur § Corpus luteum degenerates Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings
Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings
Ovarian Cycle Figure 16. 12 c Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings
Uterine (Menstrual) Cycle Figure 16. 12 d Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings
