Chapter 2. REPRODUCTIVE CHANGES IN THE FEMALE

LIFESPANReid L. Norman, PhDReid L. Norman, PhD

Professor, Pharmacology and Professor, Pharmacology and Neuroscience, TTUHSCNeuroscience, TTUHSC

Learning Objectives

• Describe how a woman’s body changes Describe how a woman’s body changes during her lifeduring her life

• Describe how reproductive hormones Describe how reproductive hormones change throughout the lifespan of a womanchange throughout the lifespan of a woman

• Define the terminology used to describe Define the terminology used to describe changes in reproductive capabilitieschanges in reproductive capabilities

• Outline the impact of menopause on health Outline the impact of menopause on health measuresmeasures

Changes in the lifespan

AGEAGE

10 20 30 40 50 60 70 80

POSTMENOPAUSALPOSTMENOPAUSALMENSTRUAL CYCLESMENSTRUAL CYCLES

MENOPAUSEMENOPAUSEPUBERTYPUBERTY

NO CYCLESNO CYCLES

E, P, LH, FSHAll low

E, P, LH, FSHAll low

E, P, LH, FSHCyclic changesE, P, LH, FSHCyclic changes

E, P - lowLH, FSH - high

E, P - lowLH, FSH - high

Childhood

• Reproductive hormone level are lowReproductive hormone level are low• LH, FSH, estrogen and progesteroneLH, FSH, estrogen and progesterone

• No menstrual cyclesNo menstrual cycles• Secondary sexual characteristics absentSecondary sexual characteristics absent• Energy devoted to growthEnergy devoted to growth

Puberty

• Transition between childhood and adultTransition between childhood and adult• Occurs between 8 – 14 yearsOccurs between 8 – 14 years• Includes the anatomical, physiological and Includes the anatomical, physiological and

behavioral changes that occur during this behavioral changes that occur during this periodperiod

Puberty• Increased GnRH release from the Increased GnRH release from the

hypothalamus stimulates LH and FSH hypothalamus stimulates LH and FSH • Increased estrogen and progesterone levelsIncreased estrogen and progesterone levels

• Secondary sexual characteristics developSecondary sexual characteristics develop• Menarche – first menstrual period – this Menarche – first menstrual period – this

is hallmark of pubertyis hallmark of puberty• Primary amenorrhea – when menarche Primary amenorrhea – when menarche

has not occurred by age 16has not occurred by age 16

Puberty

• Adolescent growth spurtAdolescent growth spurt• Estrogen causes fusion of epiphyseal Estrogen causes fusion of epiphyseal

region of long bones – terminates growthregion of long bones – terminates growth• Adrenarche – growth of axillary and pubic Adrenarche – growth of axillary and pubic

hairhair• Hormones from the adrenal glandHormones from the adrenal gland

Sexual maturity - adult

• Menstrual cycles – fertile periodMenstrual cycles – fertile period• Day 1 of cycle – first day of menstrual flowDay 1 of cycle – first day of menstrual flow• Eumenorrhea – cycles of 26-35 dEumenorrhea – cycles of 26-35 d• Pregnancy and lactation interrupt cyclePregnancy and lactation interrupt cycle• Hormonal birth control – mimics cyclic Hormonal birth control – mimics cyclic

fluctuation of ovarian steroids (E and P)fluctuation of ovarian steroids (E and P)• Cyclic fluctuations of LH, FSH, E and PCyclic fluctuations of LH, FSH, E and P

Menopause

• Average age in US is 51 yearsAverage age in US is 51 years• No menstrual cycles for 12 monthsNo menstrual cycles for 12 months• Cause of menopause – ovaries have been Cause of menopause – ovaries have been

depleted of primary folliclesdepleted of primary follicles• LH and FSH increase to stimulate follicles LH and FSH increase to stimulate follicles

to produce estrogento produce estrogen

Menopause

• Symptoms – most related to decreased Symptoms – most related to decreased circulating estrogen levelscirculating estrogen levels• Hot flashes – vasomotor instabilityHot flashes – vasomotor instability

• These are real increases in body These are real increases in body temperature temperature

• Mood changesMood changes• Urogenital changesUrogenital changes

Postmenopause

• Today – this averages about 30 years in USToday – this averages about 30 years in US• Increased risk for Increased risk for

• OsteoporosisOsteoporosis• Alzheimer’s dementiaAlzheimer’s dementia• DepressionDepression• Cardiovascular diseaseCardiovascular disease• Breast and endometrial cancerBreast and endometrial cancer

Postmenopause

• HRT – hormone replacement therapyHRT – hormone replacement therapy• Estrogen or estrogen + progesteroneEstrogen or estrogen + progesterone• Effective in treatingEffective in treating

• OsteoporosisOsteoporosis• Alzheimer’s diseaseAlzheimer’s disease• Hot flashesHot flashes• Cardiovascular changesCardiovascular changes

• Increased risk for breast cancer in some womenIncreased risk for breast cancer in some women