Chapter 81: Female Physiology Before Pregnancy and Female
Hormones Guyton and Hall, Textbook of Medical Physiology, 12
edition
Slide 2
Physiologic Anatomy of the Female Sexual Organs Fig. 81.1
Female reproductive organs
Slide 3
Physiologic Anatomy of the Female Sexual Organs Fig. 81.2
Internal structure of the uterus, ovary, and a uterine tube
Slide 4
Female Hormonal System Gonadotropin releasing hormone (GnRH)
Anterior pituitary sex hormones: follicle stimulating hormone (FSH)
and leutinizing hormone (LH) Ovarian Hormones-Estrogen and
Progesterone
Slide 5
Female Hormonal System Fig. 81.3 Approximate plasma
concentrations of the gonadotropins and ovarian hormones during the
normal female sexual cycle
Slide 6
Monthly Ovarian Cycle Gonadotropin Hormones and Their Effects
on the Ovaries a.Ovarian changes that occur during the menstrual
cycle are due entirely to FSH and LH b.Ovaries remain inactive
until 9-12 years of age when the pituitary secretes FSH and LH
leading to puberty c.Menarche-the first menstrual cycle d.Cyclic
variations (see Fig. 81.3)
Slide 7
Monthly Ovarian Cycle Gonadotropin Hormones and Their Effects
on the Ovaries e.The stimulatory effects result from activation of
the cAMP second messenger system in the cell cytoplasm f.Causes the
formation of protein kinases and the phosphorylation of key
enzymes
Slide 8
Monthly Ovarian Cycle Follicular Phase of the Cycle Fig. 81.4
Stages of follicular growth in the ovary, also showing formation of
the corpus luteum
Slide 9
Monthly Ovarian Cycle Follicular Phase of the Cycle a.Moderate
enlargement of the ovum initially b.Development of antral and
vesicular follicles c.Only one follicle matures fully each month
d.Ovulation-surge of LH is necessary
Slide 10
Monthly Ovarian Cycle Follicular Phase of the Cycle Fig. 81.5
Postulated mechanism of ovulation
Slide 11
Monthly Ovarian Cycle Luteal Phase a.Development of the corpus
luteum within hours after ovulation b.Leutinizing effect of LH
c.Secretion by the corpus luteum-progesterone and estrogen
d.Involution of the corpus luteum and onset of the next ovarian
cycle
Slide 12
Functions of the Ovarian Hormones Chemistry of the Sex
Hormones-Estrogens a.Estrogens-in the normal nonpregnant female
estrogens are secreted in significant quantities only by the
ovaries b.During pregnancy tremendous quantities are secreted by
the placenta c.Only 3 estrogens are present in significant
quantities: beta-estradiol, estrone, and estriol. The prinicpal
estrogen secreted by the ovary is beta-estradiol
Slide 13
Functions of the Ovarian Hormones Chemistry of the Sex Hormones
Fig. 81.6 Synthesis of the principal female hormones
Slide 14
Functions of the Ovarian Hormones Chemistry of the Sex
Hormones-Progestins a.Most important is progesterone b.In normal
nonpregnant females, it is secreted only during the latter half of
the ovarian cycle (by the corpus luteum) c.During pregnancy, it is
produced by the placenta, especially after the 4 th month
Slide 15
Functions of the Ovarian Hormones Chemistry of the Sex
Hormones-Progestins Fig. 81.7 Interaction of follicular theca and
granulosa cells in the production of estrogens
Slide 16
Functions of the Ovarian Hormones Chemistry of the Sex
Hormones-Progestins d.Estrogens and progesterone are transported in
the blood bound to plasma proteins e.The liver functions in
estrogen degradation f.Progesterone is degraded almost immediately
after secretion
Slide 17
Functions of the Ovarian Hormones Functions of the
Estrogens-Effects on Primary and Secondary Sex Characteristics a.At
puberty, the ovaries, fallopian tubes, uterus, and vagina all
increase several times in size b.External genitalia also change
with added fat deposition c.Cause the glandular tissues of the
fallopian tubes to proliferate d.Act on the breasts to (1)
development of the stromal tissues, (2) growth of extensive ductile
system, and (3) deposition of fat
Slide 18
Functions of the Ovarian Hormones Functions of the
Estrogens-Effects on Primary and Secondary Sex Characteristics
e.Inhibit osteoclastic activity of the bones and therefore
stimulate bone growth f.Cause uniting of the epiphyses of the long
bones (effects of estrogen on the female are stronger than the
effects of testosterone in the male) g.Osteoporosis of the bones is
caused by estrogen deficiency in old age h.Slightly increase
protein deposition
Slide 19
Functions of the Ovarian Hormones Functions of the
Estrogens-Effects on Primary and Secondary Sex Characteristics
i.Increase body metabolism and fat deposition j.Have little effect
on hair distribution k.Cause the skin to become more vascular,
smooth, and soft l.Can cause sodium and water retention by the
kidney tubules, but is generally of little significance
Slide 20
Functions of the Ovarian Hormones Functions of Progesterone
a.Promotes secretory changes in the uterus; preparing the uterus
for the implantation of the ovum b.Promotes increased mucosal
secretions by the Fallopian tubes c.Promotes the development of the
breasts; the lobules and the alveoli to become secretory in
nature
Slide 21
Functions of the Ovarian Hormones Monthly Endometrial Cycle and
Menstruation a.Proliferation of the uterine endometrium
b.Development of secretory changes in the endometrium
c.Desquamation of the endometrium (menstruation)
Slide 22
Functions of the Ovarian Hormones Monthly Endometrial Cycle and
Menstruation Fig. 81.8 Phases of endometrial growth and
menstruation during each monthly female sexual cycle
Slide 23
Functions of the Ovarian Hormones Proliferative Phase (Estrogen
Phase) a.Under the influence of estrogens, the stromal and
epithelial cells proliferate rapidly b.Before ovulation occurs, the
endometrium thickens due to growth of cells, glands, and vessels
c.Endometrial glands secrete a thin stringy mucus (helps to guide
sperm)
Slide 24
Functions of the Ovarian Hormones Secretory Phase
(Progestational Phase) a.After ovulation occurs, progesterone and
estrogen are secreted in large quantities by the corpus luteum
b.Estrogen causes additional cell proliferation and progesterone
causes swelling and secretory development of the endometrium
c.Whole purpose is to produce an endometrium that contains large
amounts of stored nutrients for the ovum if implanted d.Uterine
secretions provide nutrition for the implanting ovum (uterine
milk)
Slide 25
Functions of the Ovarian Hormones Menstruation a.If the ovum is
not fertilized, about 2 days before the end of the monthly cycle,
the corpus luteum involutes and estrogen and progesterone
production decreases b.Rapid involution of the endometrium, blood
vessels become vasospastic and initiates necrosis c.Gradually the
necrotic layers separate from the endometrium and sloughing
occurs
Slide 26
Regulation of the Female Monthly Rhythm Hypothalamus Secretes
GnRH, Which Causes the Anterior Pituitary to Release FSH and LH
a.Intermittent pulsatile secretion of GnRH stimulates the pulsatile
release of LH b.The neuronal activity that causes the pulsatile
release is primarily in the arcuate centers
Slide 27
Regulation of the Female Monthly Rhythm Hypothalamus Secretes
GnRH, Which Causes the Anterior Pituitary to Release FSH and LH
Fig. 81.9 Upper curve: pulsatile change in LH in the peripheral
circulation Lower curve: minute by minute recording of multi-unit
electrical activity
Slide 28
Regulation of the Female Monthly Rhythm Negative Feedback
Effects of Estrogen and Progesterone to Decrease FSH and LH Fig.
81.10 Feedback regulation of the hypothalamic-pituitary-ovarian
axis in females.
Slide 29
Regulation of the Female Monthly Rhythm Negative Feedback
Effects of Estrogen and Progesterone to Decrease FSH and LH
a.Estrogen has a strong effect to inhibit the production of both
FSH and LH b.These effects operate mainly on the anterior pituitary
but also on the hypothalamus to a lesser extent c.Inhibin from the
corpus luteum inhibits mainly FSH and to a lesser extent, LH
Slide 30
Regulation of the Female Monthly Rhythm Positive Feedback
Effect of Estrogen Before Ovulation a.For reasons unknown, the
anterior pituitary secretes increased amounts of LH for 1-2 days
beginning 24-48 hours prior to ovulation b.Ovulation does not occur
unless this pre-ovulatory surge does
Slide 31
Regulation of the Female Monthly Rhythm Feedback Oscillation of
the Hypothalamic- Pituitary-Ovarian System a.Postovulatory
secretion of the ovarian hormones and depression of the pituitary
gonadotropins b.Follicular growth phase-2-3 days before
menstruation, the corpus luteum has regressed and secretion of
estrogen, progesterone, and inhibin decreases; this releases the
hypothalamus and anterior pituitary from the negative feedback
control of those hormones
Slide 32
Regulation of the Female Monthly Rhythm Feedback Oscillation of
the Hypothalamic- Pituitary-Ovarian System c.A day or so later, FSH
and LH begin to increase d.This initiates follicle growth
Preovulatory Surge of LH and FSH Causes Ovulation
Slide 33
Regulation of the Female Monthly Rhythm Puberty and Menarche
a.Puberty-onset of adult sexual life b.Menarche-the beginning of
the cycle of menstruation; usually begins between the ages of 11-16
(average 13)
Slide 34
Regulation of the Female Monthly Rhythm Puberty and Menarche
Fig. 81.11 Total rates of secretion of gonadotropic hormones
throughout the sexual lives of females and males Fig. 81.12
Estrogen secretion throughout the sexual life of the human
female
Slide 35
Abnormalities of Secretion by the Ovaries Hypogonadism- reduced
secretion by the ovaries Hypersecretion by the Ovaries
Slide 36
Female Sexual Act Stimulation of the Female Sex Act Female
Erection and Lubrication Female Orgasm