Thibodeau: Anatomy and Physiology, 5/e Chapter 32: Female Reproductive System Female anatomy is identified here, and the physiological pursuit of the menstrual cycle is the most well-delineated endocrinological mechanism covered the textbook. Earlier lessons of hormone action, negative feedback, and metabolism apply.
Objectives After students have completed this chapter, they should be able to: 1.
List the essential and accessory sex organs of the female reproductive system and give the generalized functions of each.
2.
Discuss the structure of the uterus, including details of its wall layers, size, shape, cavities, blood supply, and ligaments.
3.
Locate the uterus in the pelvic cavity and compare its position with the abnormal position of retroflexion.
4.
Identify the functions of the uterus.
5.
Discuss the location, structure, divisions, and functions of the uterine tubes.
6.
Describe the structure of the ovaries and explain the steps in development of mature ova from ovarian follicles.
7.
Identify the two functions of the ovaries.
8.
Discuss the location, structure, and primary functions of the vagina.
9.
Identify the structures that together constitute the female external genitals.
10.
Explain the clinical importance of the perineum during childbirth.
11.
Describe the structure of the breasts and the mechanism controlling lactation.
12.
Identify the phases of the endometrial, or menstrual, cycle.
13.
Explain the hormonal control of cyclical changes that occur in the ovaries and uterus.
14.
Discuss the importance of the female reproductive cycles.
15.
Compare and contrast menarche and menopause.
Lecture Outline I.
Overview of the Female Reproductive System (p. 912) A.
B.
Function of the female reproductive system 1.
Production of gametes needed for continuation of the species
2.
Proper functioning of anatomy and hormones required for reproduction
3.
Protection and nutrition to developing offspring
Structural plan of the female reproductive system (Figs. 32-1, 32-2) 1.
Essential organs of reproduction—ovaries (gonads)
2.
Accessory organs of reproduction a.
Ducts, including uterine tubes, uterus, vagina
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Chapter 32: Female Reproductive System
C.
2
b.
Vulva (external genetalia)
c.
Sex glands
Perineum (Fig. 32-1B) 1.
From symphysis pubis to coccyx; from ischial tuberosity on either side
2.
Divided into two triangles formed by drawing a line from ischial tuberosity to ischial tuberosity a.
Urogenital triangle 1)
b.
Anal triangle 1)
3.
The anterior triangle with the external genitalia and urinary opening
The posterior triangle with the anus
Of clinical importance because the perineum can tear between the vaginal orifice and the anus during childbirth a.
Episiotomy sometimes performed to avoid the tear and
improve healing II.
Ovaries (Figs. 32-1, 32-2) A.
B.
Location of the ovaries (p. 914) 1.
Posterior body wall, laterally, on either side of the uterus and below and behind the uterine tubes
2.
Held in place by ligaments a.
Mesovarian ligament attaches ovary to broad ligament
b.
Ovarian ligament attaches ovary to uterus
Microscopic structure of the ovaries (Figs. 32-3, 32-4) 1.
Surface layer is covered by the germinal epithelium (cells do not form ova)
2. Deep to the germinal epithelium is connective tissue matrix with thousands of ovarian follicles 3.
Each follicle is made of follicular cells surrounding a primary oocyte
4. Follicular cells can produce hormones; as the follicle develops, a cavity (antrum) develops, Follicular cells multiply and the follicle grows, finally rupturing to the abdominopelvic cavity C.
Functions of the ovaries 1.
Oogenesis a.
2.
Ovulation a.
3.
The release of the ova
Production of female sex hormones a.
III.
The production of ova
Are also endocrine glands, producing estrogens and progesterone
Uterus (p. 916) Copyright © 2003 Mosby, Inc. All Rights Reserved.
Chapter 32: Female Reproductive System
A.
3
Structure of the uterus (Fig. 32-2) 1.
2.
Size and shape of the uterus a.
Size: 7.5 cm long and 5 cm wide (if woman has never been pregnant)
b.
Parts 1)
Cervix—narrow parts that communicates with vagina
2)
Body—major part
3)
Fundus—above the uterine tube entrance
Wall of the uterus a.
Endometrium 1)
2) b.
Stratum compactum—innermost simple columnar epithelium
b)
Stratum spongiosum—made of loose connective tissue
c)
Stratum basale—dense layer attaching to myometrium
Stratum compactum and stratum spongiosum— slough off during menstruation and child birth
Three layers of smooth muscle
Parietal peritoneum 1)
3.
a)
Myometrium 1)
c.
Three layers
Covers part of the uterus (not the cervix, however)
Cavities of the uterus (p. 916) a.
Basically, a flat cavity except where the cervix joins the body 1)
Internal os—the constriction between body and cervix
2)
Cervical canal
3) External os—the constriction between the cervical canal and the vagina 4.
Blood supply of the uterus a.
B.
Location of the uterus (Figs. 32-1) 1.
C.
Rich blood supply
Between the urinary bladder and rectum
Position of the uterus (Fig. 32-5) 1.
2.
Normal a.
Flexed forward over the bladder
b.
Cervix joining the vagina at right angle
Retroflexion
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Chapter 32: Female Reproductive System
a. 3.
Flexed backward
Prolapse a.
4.
Uterus descending into vaginal canal
Uterine ligaments (Figs. 32-1) a.
Broad ligaments (two) 1)
b.
c.
Anterior uterus to bladder
Round ligaments 1)
From upper outer angles of uterus through inguinal canal to labia majora
Functions of the uterus 1.
2.
If fertilization occurs: a.
Allows sperm to pass through to uterine tubes
b.
Provides place for fertilized ovum to implant
c.
Provides "uterine milk" until the placenta forms
d.
Provides exchange site for nutrients, wastes, and gases for placenta
e.
Regulates rhythmic contractions that expel the offspring
If no fertilization occurs: a.
IV.
Posterior uterus to rectum
Anterior ligament 1)
e.
Uterus to sacrum extending around rectum
Posterior ligament 1)
d.
Extend laterally
Uterosacral ligaments (two) 1)
D.
4
Menstruation
Uterine Tubes (p. 918) A.
B.
Location of the uterine tubes (Fig. 32-2) 1.
About 10 cm long
2.
Lie horizontal to uterus
3.
Are along the upper free margin of the broad ligament
Structure of the uterine tubes 1.
Wall of the uterine tubes (Figs. 32-6, 32-7) a.
2.
Three layers 1)
Inner mucous layer
2)
Middle smooth muscle layer
3)
Outer serosa
Divisions of the uterine tubes
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Chapter 32: Female Reproductive System
a.
Isthmus 1)
b.
3.
V.
Dilated middle part
Infundibulum 1)
Funnel-shaped lateral part
2)
Funnel partially surrounding the ovary
3)
Has fringelike projections called fimbriae
Histology of the uterine tubes a.
C.
Medial third, which joins the uterus
Ampulla 1)
c.
5
Inner epithelium is ciliated. Cilia draw peritoneal fluid into the uterine tubes and the uterus.
Function of the uterine tubes 1.
Fertilization site
2.
Transport of ovum
Vagina (p. 919) A.
B.
Location of the vagina 1.
Between the rectum and the urethra and bladder
2.
Extends upward and backward
Structure of the vagina 1.
A collapsible tube 7 to 8 cm long
2.
Lined with mucous epithelium with rugae (Fig. 32-2)
3. Anterior wall shorter than the posterior since the cervix of the uterus joins it at a right angle (Fig. 32-1) 4. The fornix is the part of the vagina that extends around the opening of the cervix (Figs. 32-1, 32-2) 5. The hymen is a mucous membrane that partially to completely covers the vaginal orifice (Figs. 32-1, 32-8) C.
VI.
Functions of the vagina 1.
Lubricates and stimulates the glands penis during intercourse
2.
Receptacle for semen
3.
Lower portion of birth canal
4.
Transport of tissue shed from lining of uterus during menstruation
Vulva (External Genitalia) (p. 920) A.
Structure of the vulva (Fig. 32-8) 1.
Mons pubis a.
2.
Pad of fat anterior to symphysis pubis; hair covered after puberty
Labia majora
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Chapter 32: Female Reproductive System
3.
4.
5.
6.
a.
Fat- and connective tissue-filled swellings at the lateral edges of the vulva
b.
Covered with pubic hair on outer surface and not on inner surface
c.
Inner surface containing many sweat and sebaceous glands
d.
Homologous to penis
Labia minora a.
Narrow lips, medial to the labia majora
b.
Merging anteriorly and forming the prepuce over the clitoris
c.
Homologous to corpora cavernosa
Vestibule a.
The area between the two labia minora
b.
Two openings into it
9.
2)
Vaginal orifice for reproductive system (posterior opening)
Located where the labia minora merge aneriorly
b.
Covered with prepuce
c.
Homologous to corpora cavernosa and glans of penis
Urinary meatus Opening of the urethra between the clitoris and the vaginal orifice
Vaginal orifice Opening of the vagina, posterior to the urethral meatus
Greater vestibular glands (Bartholin's glands) a.
Two mucous glands, one on either side of the vaginal orifice
b.
Provide lubrication
c.
Homologous to bulbourethral gland
Lesser vestibular gland (Skene's glands) a.
B.
Urethral meatus (orifice) for urinary system (anterior opening)
a.
a. 8.
1)
Clitoris
a. 7.
6
Several mucous glands opening near the urethral meatus
Functions of the vulva 1.
Protective function (mons pubis, labia majora, and labia minora)
2. During sexual arounsal, the cavernous tissue in the clitoris and the labia become erect or swollen VII.
Breasts (p. 920) A.
Location and size of breasts (Fig. 32-9) 1.
Posterior surface lying upon the pectoralis muscles
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Chapter 32: Female Reproductive System
2. B.
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Size determined by the amount of adipose tissue
Structure of the breasts (Fig. 32-9) 1.
15 to 20 lobes per breast a.
Each lobe is separated from others by connective tissue
b. The ducts of the mammary glands (alveoli) in each lobe connect to form a single lactiferous duct
C.
c.
A swelling called the lactiferous sinus is found on lactiferous duct
d.
The lactiferous ducts each terminate with an opening on the nipple surface
e.
Around the nipple is a pigmented area—the areola
Function of the breasts (Fig. 32-10) 1.
Mechanism controlling lactation (p. 921) a.
Estrogen promotes duct development
b.
Progesterone stimulates mammary gland alveoli development
c. Loss of placenta decreases estrogens present and stimulates adenohypophysis production of prolactin 1) d.
Sucking stimulates adenohypophysis production of oxytocin 1)
2.
VIII.
Prolactin stimulates milk secretion
Oxytocin stimulates ejection of milk
Importance of lactation a.
Milk provides the correct nutrients in the correct proportions for the infant
b.
Human milk provides passive immunity with mother's antibodies
c.
Nursing creates bonding between mother and child
Female Reproductive Cycles (p. 922) A.
Recurring cycles 1.
Menarche a.
Onset on menses
2.
Menopause, or climacteric
3.
Ovarian cycle (Fig. 32-14) a.
At birth, all of the primary follicles are formed
b.
The ova are suspended in meiosis prophase I
c. After menarche, several primary follicle ova resume meiosis (halts in metaphase II), and the follicles form secondary follicles d.
One follicle grows fastest and bursts into the abdominal cavity (ovulation)
e.
Meiosis is completed only after the ovum is fertilized
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Chapter 32: Female Reproductive System
4.
f.
Follicular cells of ruptured follicle form the corpus luteum
g.
Corpus luteum produces progesterone
h.
If no fertilization occurs, corpus luteum disintegrates, starting after 7 to 8 days
Endometrial, or menstrual, cycle (Fig. 32-14) a.
Menses (menstrual period)—days 1 to 5
b.
Postmenstrual (preovulatory; same as estrogenic or follicular phase)—days 6 to 13 or 14
c.
Ovulation—day 14 (28-day cycle) (Fig. 32-11) 1)
d. 5.
B.
Ovum released from follicle
Premenstrual (postovulatory) phase—days 15 to 28
Myometrial cycle (p. 924) a.
6.
8
Muscle contractions for 2 weeks before ovulation
Gonadotropic cycle (produced by adenohypophysis) (Fig. 32-12) a.
FSH (follicle-stimulating hormone)
b.
LH (luteinizing hormone)
Control of female reproductive cycles (Fig. 32-12) 1.
Control of cyclical changes in the ovaries (Fig. 32-12) a.
Gonadotropins from the adenohypophysis FSH and LH 1)
2)
2.
FSH effects a)
Stimulates several primary follices and oocytes to develop
b)
Stimulates follicular cells to secrete estrogens
LH effects a)
Follicle and oocyte growth completion
b)
Ovulation
c)
Formation of the corpus luteum
Control of cyclical changes in the uterus (p. 925) a.
Changes due to blood concentration changes of estrogen and progesterone 1)
2)
Results of increased blood estrogen a)
Endometrial proliferation
b)
Endometrial gland growth
c)
Increase of endrometrial water content
d)
Increase in myometrial contractions
Results of increased blood progesterone a)
Endometrial gland secretion
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Chapter 32: Female Reproductive System
3.
C.
IX.
X.
XI.
b)
Increase of endometrial water content
c)
Decrease in myometrial contractions
Control of cyclical changes in gonadotropin secretion (Fig. 32-13) a.
The hypothalamus senses low levels of estrogens and progesterone, so it secretes gonadotropin-releasing hormone (GnRH)
b.
Adenohypophysis secretes FSH and LH
c.
FSH and LH stimulate follicular development and formation of corpus luteum
d.
Corpus luteum produces estrogen and progesterone, which inhibit the hyothalamus secretion of GnRH
e.
Corpus luteum disintegrates in 7 to 8 days, resulting in the decrease of estrogen and prog esterone levels in the blood
f.
The hypothalamus senses low levels of estrogens and progesterone and again secretes GnRH
Importance of female reproductive cycles (Fig. 32-14) 1.
D.
9
Various female cycles are all interrelated
Menarche and menopause (Fig. 32-15) 1.
Menarche occurs at around age 13
2.
Menstrual cycle continues for about 30 years
3.
Menopause occurs usually between 45 and 50 years of age
Cycle of Life: Female Reproductive System A.
Becomes functional at puberty
B.
Meiotic development of ova starts before birth; then at puberty (as a result of hormonal control) meiosis resumes, with an ovum released each month
C.
At menopause there is a change in hormone production, resulting in a lack of ovum release and inability to reproduce
The Big Picture: Female Reproductive System and the Whole Body (p. 929) A.
Requires reproductive system from both parents
B.
Involves many other organ systems
Mechanisms of Disease: Disorders of the Female Reproductive System (p. 930) A.
B.
Hormonal and menstrual disorders 1.
Dysmenorrhea
2.
Amenorrhea
3.
Dysfunctional uterine bleeding (DUB)
4.
Premenstrual syndrome (PMS)
Infection and inflammation 1.
Pelvic inflammatory disease (PID) a.
Salpingitis
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Chapter 32: Female Reproductive System
b. 2. C.
D.
Oophritis
Vaginitis
Tumors and related conditions 1.
Myoma or fibromyoma
2.
Endometriosis
Sexually transmitted diseases (STDs) (Table 32-1)
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