. Biology of Reproduction, lecture on Menopause
University of South
Dakota......Department of Biology

Biology of Reproduction

Fall 1998

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text: Human Reproductive Biology 2nd Edition - R.E. Jones: Read pages 82-87 for this lecture


XVI. Menopause                          back to XV. Menstrual Cycle

	A. permanent 2o amenorrhea

		1. begins with oligomenorrhea

			a. and lengthened cycles

	B. Average Age = 49.8

		1. range = 35-55

	C. Symptoms of Transition (physical symptoms more permanent)

		1. hot flashes = skin vasodilation

			a. ­ 1oC

				i. occur in 1/4 women

		2. weight gain

		3. voice deepening
							from increased adrenal androgens
		4. minor hirsutism

		5. vaginal dryness

		6. Osteoporosis (very common)

			a. weakening of bones

				i. calcium loss

			b. 1 in 4 women over 60

				i. 12th leading cause of death in the US

		7. fatigue

		8. irritability 
						symptoms with emotional component temporary

		9. depression

		10. insomnia

		11. Treatment = Estrogens 		(ERT)

			a. usually estrone sulfate

			b. prevents osteoporosis by aiding calcium uptake

				i. increased risk of osteoporosis comes from:

					(1) lack of exercise

					(2) low Ca++ intake

					(3) smoking

					(4) alcohol

					(5) caffeine

					(6) no pregnancy

					(7) fair complexion

					(8) thin and small bones

					(9) early menopause

					(10) genetic predisposition
					     - family history of osteoporosis

			c. helps prevent cardiovascular disease

			d. reverses vaginal dryness

			e. reverses depression

			f. increased endometrial cancer risk

				i. 1-5 years ® ­ 5.6X

				ii. 7 or more years ® ­ 139X

				iii. addition of P to E replacement abrogates
				     the cancer risk

	D. Cause of Menopause

		1. Depletion of Ovarian Follicles

			a. no 3o follicles

				i. reduced receptors for LH and FSH

			b. no estrogens produced

				i. follicular inhibin decreases

				ii. androgens increase

					(1) during ovarian decline

			c. negative feedback reduced

				i. 10X increase in FSH and LH in the blood

		2. Timing of Menopause

			a. early menopause increases with:

				i. poor nutrition

				ii. smoking

				iii. identical twins

				iv. no pregnancy

				v. 2o amenorrhea for other reasons

			b. delayed menopause

				i. pregnancy

					(1) more follicles may be lost to atresia
					    in non-cycling ovaries than cycling

					(2) ovaries are supported by hCG during pregnancy

					(3) P may be related to lengthened ovarian life

				ii. developed countries have increasing average age
				   of menopause

				iii. earlier menarche may result in later menopause

XVII. Events leading to Fertilization

University of South
Dakota......Department of Biology