Chapter 2. REPRODUCTIVE CHANGES IN THE FEMALE LIFESPAN Reid L. Norman, PhD Professor, Pharmacology and Neuroscience, TTUHSC

Learning Objectives Describe how a woman’s body changes during her life Describe how reproductive hormones change throughout the lifespan of a woman Define the terminology used to describe changes in reproductive capabilities Outline the impact of menopause on health measures

Changes in the lifespan PUBERTY MENOPAUSE E, P, LH, FSH All low E, P, LH, FSH Cyclic changes E, P - low LH, FSH - high NO CYCLES MENSTRUAL CYCLES POSTMENOPAUSAL 10 20 30 40 50 60 70 80 AGE

Childhood Reproductive hormone level are low LH, FSH, estrogen and progesterone No menstrual cycles Secondary sexual characteristics absent Energy devoted to growth

Puberty Transition between childhood and adult Occurs between 8 – 14 years Includes the anatomical, physiological and behavioral changes that occur during this period

Puberty Increased GnRH release from the hypothalamus stimulates LH and FSH Increased estrogen and progesterone levels Secondary sexual characteristics develop Menarche – first menstrual period – this is hallmark of puberty Primary amenorrhea – when menarche has not occurred by age 16

Puberty Adolescent growth spurt Estrogen causes fusion of epiphyseal region of long bones – terminates growth Adrenarche – growth of axillary and pubic hair Hormones from the adrenal gland

Sexual maturity - adult Menstrual cycles – fertile period Day 1 of cycle – first day of menstrual flow Eumenorrhea – cycles of 26-35 d Pregnancy and lactation interrupt cycle Hormonal birth control – mimics cyclic fluctuation of ovarian steroids (E and P) Cyclic fluctuations of LH, FSH, E and P

Menopause Average age in US is 51 years No menstrual cycles for 12 months Cause of menopause – ovaries have been depleted of primary follicles LH and FSH increase to stimulate follicles to produce estrogen

Menopause Symptoms – most related to decreased circulating estrogen levels Hot flashes – vasomotor instability These are real increases in body temperature Mood changes Urogenital changes

Postmenopause Today – this averages about 30 years in US Increased risk for Osteoporosis Alzheimer’s dementia Depression Cardiovascular disease Breast and endometrial cancer

Postmenopause HRT – hormone replacement therapy Estrogen or estrogen + progesterone Effective in treating Osteoporosis Alzheimer’s disease Hot flashes Cardiovascular changes Increased risk for breast cancer in some women