Chapt. 4 Menstrual Cycle wk 3
3 Phases of Menstrual Cycle:
*Average cycle- 28 days* 3 Phases: 1. The Menstrual Phase: 1-5 days 2. The Proliferative Phase: 6-14 days 3. The Secretory Phase: 15-28 days endometrium is at its thickest
Follicular Development:
-3-7 or 5-7 follicles stimulated each month by FSH -Dominant follicle is Graafian Follicle -Ruptures through tunica albuginea at ovulation -Other follicles undergo artresia & form scar tissue Corpus Albicans -little fluid is normal in posterior cul de sac blood and/ or fluid drain to posterior cul de sac at ovulation -Follicles are measured if large or in patient undergoing ovulation induction *Follicle ruptures between 1.8-2.5 cm or 2.0 average* *Mittelschmerz is mid cycle pain associated with ovulation may have twins
Menstruation:
-A cycle process whereby the endometrial lining is shed if implantion of a conceptus has not occured *Starts at Menarche- 10-14 yrs* *Ends at Menopause- 45-55 yrs*
The Secretory Phase:
-Also called Luteal Phase -Begins at ovulation -Ends when menstruation starts when shedding -Glandular & Vascular changes in endometrium -Primarily under influence of progesterone -Absence of fertilization results in fall in estrogen &a progesterone, start of menstruation -Endometrium is thickest during this phase
Oral Contraceptives:
-Combined estrogen, progestin birth control pills, progestin only pills or implants prevent the pituitary glands release of hormones that stimulate ovulation
Abnormal Menstrual Patterns:
-Dysfunctional Uterine Bleeding DUB: vaginal bleeding not related to menstrual Cycle -Hypermenorrhea: excessive volume during cyclic menstrual bleeding -Hypomenorrhea: abnormally small amount of menstrual bleeding *Polymenorrhea: frequent menstrual bleeding less than 21 days apart* -Oligomenorrhea: menstrual bleeding greater than 35 days apart -Menorrhagia: excessive bleeding in time and/or volume -Dysmenorrhea: painful uterine bleeding -Amenorrhea: absence of menstrual flow *Primary: patient never menstruated* *Secondary: patient had menstrual periods but stopped
The Menstrual Phase:
-Endometrium degenerates -Sloughs off the myometrium -Expelled as menses *Typically 12-24 hrs of heavy flow, with less flow for the next 4-7 days*
Hormonal Regulation:
-Endometrium responds to estrogen &a progesterone levels in the blood *Levels Controlled By Feedback System Between: 1. Ovaries 2. Hypothalamus 3. Anterior hypophysis of pituitary
Things to Remember:
-Proliferative Phase: estrogen -Secretory Phase: progesterone -LH causes ovulation to occur -Hypothalamus: GnH -Pituitary: FSH & LH -Ovaries: estrogen, progesterone
The Proliferative Phase:
-Regrowth of endometrium after 5 days -Mainly under influence of estrogen -Estrogen released by ovarian follicles -Ends at ovulation *Ovulation on approximately day 14 of a 28 day cycle*
Chain of Events Pituitary Gland:
-Releases FSH -FSH causes numerous follicles in ovary to grow *Follicles produce estrogen* *Rising estrogen levels trigger pituitary to release Luteinizing Hormone LH *Ride in LH causes ovulation to occur
Chain of Events Hypothalamus:
-Secretes Gonad Releasing Hormone GnH -Rise in GnH causes pituitary gland to release Follicle Stimulating Hormone FSH -It controls the body's temperature -In charge of making the body hungry & thirsty -Charges Vascular system
Hormone Replacement Therapy HRT:
-Used to Treat the Symptoms of Menopause: 1. Hot flashes 2. Mood swings 3. Sleep disorders 4. Vaginal dryness *Pros: decreases menopausal symptoms* *Cons: increased risk of breast cancer, uterine cancer, ovarian cancer*
Endometrium Sizes:
Endometrium thick to 1cm cannot be bigger than 4cm
AKA: Corpus Luneum
Yellow body
