The Reproductive System

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32

• The Reproductive System

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Learning Outcomes (cont.)

• 32.1 Summarize the organs of the male
  reproductive system including the locations,
  structures, and functions of each.
• 32.2 Describe the causes, signs and symptoms,
  and treatment of various disorders of the male
  reproductive system.
• 32.3 Summarize the organs of the female
  reproductive system including the locations,
  structures, and functions of each.
• 32.4 Describe the causes, signs and symptoms,
  and treatment of various disorders of the female
  reproductive system.

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Learning Outcomes (cont.)

• 32.5 Explain the process of pregnancy, including
  fertilization, the prenatal period, and fetal
  circulation.
• 32.6 Describe the birth process, including the
  postnatal period.
• 32.7 Compare several birth control methods and
  their effectiveness.
• 32.8 Explain the causes of and treatments for
  infertility.
• 32.9 Describe the causes, signs and symptoms,
  and treatments of the most common sexually
  transmitted infections.

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Introduction

• Male and female reproductive systems
• Function together to produce offspring
• Produce important hormones

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The Male Reproductive System

• Testes
• Produce sperm and testosterone
• Divided into lobules
• Held in the scrotum

• Seminiferous tubules
• In the lobules of the testes
• Contain spermatogenic cells
• Interstitial cells produce testosterone

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Sperm Cell Formation

• Spermatogenesis

Spermatogonium (46 chromosomes)
Primary spermatocytes (46 chromosomes)
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Sperm Cell Formation (cont.)

• Head
• Nucleus with 23 chromosomes
• Covered by an acrosome
• Midpiece - mitochondria

• Tail
• Flagellum
• Propelsthe sperm

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Internal Accessory Organs Male

• Epididymis where spermatids mature into sperm
• Vas deferens carries sperm cells to urethra

• Seminal vesicles secrete seminal fluid
• Sugar
• Prostaglandins

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Internal Accessory Organs Male (cont.)

• Prostate gland
• Alkaline fluid that protects sperm
• Contractions assist with expulsion of semen

• Cowpers glands fluid to lubricate end of penis
• Semen
• Sperm cells
• Fluids

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External Organs Male

• Scrotum
• Pouch that holds the testes away from the body
• Lined with serous membrane that secrets fluid

• Penis
• Shaft
• Glans penis
• Prepuce
• Functions
• Deliver sperm
• Urination

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Erection, Orgasm, and Ejaculation

• Erection erectile tissue becomes engorged with
  blood
• Orgasm - emission occurs
• Ejaculation semen is forced out of the urethra

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Male Reproductive Hormones

• Gonadotropin-releasing hormone (GnRH)
• Follicle-stimulating hormone (FSH)
• Luteinizing hormone (LH)
• Testosterone
• Secondary sex characteristics
• Maturation of male reproductive organs
• Regulated by negative feedback

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Apply Your Knowledge
Matching ___ Vasectomy ___ Mixture of sperm
and fluids ___ Sperm cell formation ___ Secrete
alkaline fluid/ prostaglandins ___
Produce testosterone ___ GnRH ___ Erectile
tissue
ANSWER

1. Spermatogenesis
2. Testes
3. Penis
4. Vas deferens
5. Hypothalamus
6. Semen
7. Seminal vesicle

D
F
A
G
B
Correct!
E
C
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Common Diseases and Disorders of the Male
Reproductive System
Disease/Disorder Description
Benign prostatic hypertrophy (BPH) Nonmalignant enlargement of the prostate gland
Epididymitis Inflammation of an epididymis usually starts as an urinary tract infection
Impotence or erectile dysfunction (ED) Disorder in which erection cannot be achieved or maintained about 50 of males between 40 and 70 have some degree of ED
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Common Diseases and Disorders of the Male
Reproductive System (cont.)
Disease/Disorder Description
Prostate cancer Most common form of cancer in men over 40 risk increases with age
Prostatitis Inflammation of the prostate gland may be acute or chronic
Testicular cancer Malignant growth in one or both testicles more common in males 1530 years aggressive malignancy
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Apply Your Knowledge
ANSWER

• Match
• More common in men over 40 years old.
• Common in older men symptoms include
  difficulties with urination.
• More common in males 15-30 years old
  aggressive.
• Often starts as urinary tract infection
  symptoms include swelling of the scrotum
  and painful ejaculation.

1. BPH
2. Epididymitis
3. Prostrate cancer
4. Testicular cancer

C
A
D

B
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The Female Reproductive System

• Ovaries
• Produce ova, estrogen, and progesterone
• Medulla nerves and lymphatic and blood vessels
• Cortex ovarian follicles

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Ovaries and Ovum Formation

• Oogenesis

• Primordial follicles
• Primary oocyte
• Follicular cells

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Internal Accessory Organs Female

• Fallopian tube oviduct
• Infundibulum and fimbriae
• Fringed, expanded end of fallopian tube near
  ovary
• Function to catch an ovum
• Muscular tube
• Lined with mucous membrane and cilia
• Propels ovum toward uterus

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Internal Accessory Organs Female (cont.)

• Vagina
• Extends from uterus to outside body
• Rugae
• Wall three layers

• Uterus
• Receives embryo and sustains its development
• Divisions
• Wall three layers

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External Accessory Organs - Female

• Mammary glands
• Secretion of milk
• Structures
• Nipple
• Areola
• Alveolar glands

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External Genitalia Female

• Vulva
• Labia majora
• Adipose tissue and skin
• Form the mons pubis
• Labia minora
• Vascular folds of skin
• Form hood over clitoris
• Vestibule
• Bartholins glands

• Clitoris
• Contains female erectile tissue
• Rich in sensory nerves
• Perineum between vagina and anus

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Erection, Lubrication, and Orgasm

• Nervous stimulation
• Clitoris becomes erect
• Bartholins glands activate
• Vagina elongates
• Orgasm
• Sufficient stimulation of clitoris
• Walls of uterus and fallopian tubes contract to
  propel sperm

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Female Reproductive Hormones
Hypothalamus secretes GnRH
Anterior pituitary releases FSH LH
GnRH
Stimulates
Ovaries to produce estrogen and progesterone

• Estrogen and progesterone are responsible for
  development of secondary sex characteristics

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Reproductive Cycle

• Menstrual cycle
• Regular changes in uterine lining
• Shedding of lining and bleeding
• Menarche first menstrual period
• Menopause termination of cycle due to normal
  aging of ovaries

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Reproductive Cycle (cont.)
Anterior pituitaryreleases FSH
Uterine lining thickens
Ovarian folliclematures and secretesestrogen

• Without fertilization
• Corpus luteum degenerates
• Estrogen and progesterone levels fall
• Uterine lining breaks down menses starts
• Cycle begins again with release of FSH

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Apply Your Knowledge
YIPPEE!
True or False ___ The ovaries only produce
estrogen. ___ Ovulation is the process of ovum
formation. ___ The fallopian tube is also called
the oviduct. ___ The endometrium is the outer
layer of the uterine wall. ___ Alveolar glands
produce milk. ___Oxytocin induces the alveolar
glands to deliver milk through the
nipples. ___ Menarche is the termination of the
menstrual cycle. ___ Menopause occurs due to
normal aging of the ovaries.
ANSWER
F
produce estrogen and progesterone
F
Oogenesis
T
F
inner layer
T
F
lactiferous ducts
F
first
T
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Common Diseases and Disorders of the Female
Reproductive System (cont.)
Disease/Disorder Description
Endometriosis Tissues of uterine lining grow outside of the uterus
Fibrocystic breast disease Abnormal cystic tissue in the breast size varies related to menstrual cycle
Fibroids Benign tumors in the uterine wall
Ovarian cancer More deadly than other types detection difficult and often spreads before detection
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Common Diseases and Disorders of the Female
Reproductive System
Disease/Disorder Description
Breast cancer Second leading cause of cancer deaths in women
Cervical cancer Generally slow to develop Pap smear detects abnormal cervical cells
Cervicitis Inflammation of the cervix usually due to an infection
Dysmenorrhea Condition with severe menstrual cramps that limit normal activities
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Diseases and Disorders of the Female Reproductive
System (cont.)
Disease/Disorder Description
Premenstrual syndrome (PMS) Collection of symptoms occurring just before a menstrual period
Vaginitis/ vulvovaginitis Inflammation of the vagina or inflammation of vagina and vulva both associated with abnormal vaginal discharge
Uterine (endometrial) cancer Most common in post-menopausal women causes about 6 of cancer deaths
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Apply Your Knowledge
Matching ___ Inflammation of the
cervix A. Dysmenorrhea ___ Cancer common in
post-menopausal women B. Cervical cancer ___
Develops slowly detected by Pap
smear C. Fibroids ___ Uterine tissue grows
outside uterus D. Breast cancer ___ Second
leading cause of cancer death in
women E. Cervicitis ___ Severe menstrual
cramps F. Endometriosis ___ Benign tumors in the
uterine wall G. Uterine cancer
ANSWER
G o o d J o b !
E
G
B
F
D
A
C
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Pregnancy

• Condition of having a developing offspring in the
  uterus
• Fertilization
• Sperm penetrates cell membrane
• Zona pellucida becomes impenetrable
• Zygote
• Union of ovum and sperm nuclei
• 46 chromosomes

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The Prenatal Period

• Zygote undergoes rapid mitosis
• Morula ball of cells
• Blastocyst
• Implants in the endometrial wall
• Inner cell mass becomes the embryo
• Others plus cells from uterus form the placenta

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The Prenatal Period (cont.)

• Formation of
• Placenta
• Amnion
• Umbilical cord
• Yolk sack
• Internal organs and external structures

• Embryonic period
• Inner cell mass organizes into the primary germ
  layer
• Ectoderm
• Mesoderm
• Endoderm

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The Prenatal Period (cont.)

• Fetal period fetus
• Rapid growth
• 5th month
• Skeletal muscles active
• Growth rate slows
• 6th month gains weight

• Last 3 months fetal brain cells rapidly divide
• GI and respiratory systems last to develop

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Fetal Circulation

• Placenta and umbilical blood vessels exchange
  nutrients, oxygen, and waste products
• Unique differences
• Foramen ovale bypass lungs
• Ductus arteriosus between pulmonary trunk and
  aorta
• Ductus venosus bypasses liver

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Hormonal Changes During Pregnancy

• Human chorionic gonadotropin (HCG)
• Secreted by embryonic cells
• Maintains the corpus luteum
• Estrogen and progesterone
• Secreted by corpus luteum and placenta
• Stimulate uterine lining to thicken
• Inhibit release of FSH and LH from anterior
  pituitary gland

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Hormonal Changes During Pregnancy (cont.)

• Relaxin
• Inhibits uterine contractions
• Relaxes ligaments of pelvis
• Lactogen stimulates enlargements of mammary
  glands

• Aldosterone increases sodium and water retention
• Parathyroid hormone (PTH) blood calcium levels

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Apply Your Knowledge
What are the primary germ layers and what tissue
develops from them?

• ANSWER The primary germ layers are the
• Ectoderm nervous tissue and some epithelial
  tissue
• Mesoderm connective tissue and some epithelial
  tissue
• Endoderm epithelial tissue only

Right!
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The Birth Process

• Begins when progesterone levels fall
• Prostaglandins stimulate uterine contractions
• Uterine contractions stimulate release of
  oxytocin
• Oxytocin stimulates strong uterine contractions

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The Birth Process (cont.)

• Dilation
• Effacement
• Lasts 8 24 hours
• Expulsion or parturition
• Actual birth stage
• May take 30 minutes or less
• Placental stage
• Blood vessels constrict
• Placenta separates from uterine wall and is
  expelled

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The Postnatal Period

• Six-week period
• Neonatal period first four weeks
• Neonate adjusts to life outside uterus

• Milk production and secretion
• Prolactin
• Oxytocin
• Production continues as long as breast-feeding
  continues

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Apply Your Knowledge
What are the three stages of the birth process
and what occurs during each?

• ANSWER The three stages are
• Dilation the cervix thins, softens
  (effacement), and dilates to approximately 10 cm
• Expulsion also called parturition the actual
  birth stage
• Placental stage placenta separates from uterine
  wall and is expelled

Impressive!
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Contraception
Method Description
Coitus interruptus Penis is withdrawn from vagina before ejaculation not a reliable method
Rhythm method Requires abstinence around time of ovulation not a reliable method
Mechanical barriers Prevent sperm from entering female reproductive tract
Chemical barriers Destroy sperm in the female reproductive tract primarily spermicides often used with mechanical barriers
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Contraception (cont.)
Method Description
Oral contraceptives Birth control pills prevent ovulation by preventing LH surge
Injectable contraceptives Prevent ovulation and alter lining of uterus to prevent implantation of blastocyst
Insertable contraceptives Ring inserted vaginally and removed at the beginning of the 4th week to allow menstruation
Contraceptive implants Small rods of progesterone implanted beneath skin prevent ovulation
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Contraception (cont.)
Method Description
Transdermal contraceptives Contraceptives in the form of a patch applied weekly for 3 weeks not used the 4th week to allow menstruation
Intrauterine device (IUD) Small, solid devices placed into uterus by MD prevents implantation of blastocyst
Surgical methods Tubal ligation fallopian tube is cut and tied Vasectomy vas deferens is cut and tied
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Apply Your Knowledge
Your patient has just been told that she is
pregnant, but she does not understand why she
could get pregnant. She states, I have been
very careful in using the rhythm method of birth
control. What patient teaching would you do to
assist her to understand?
ANSWER The rhythm method is not as effective as
other birth control, because it is sometimes
difficult to tell when ovulation occurs.
Good Answer!
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Infertility

• Inability to conceive
• Primary
• Secondary
• Causes
• 15 unknown
• 35 male-related problems
• 50 female-related problems

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Infertility (cont.)

• Some male-related factors
• Impotence
• Retrograde ejaculation
• Low or absent sperm count
• Decreased testosterone

• Some female-related factors
• Pelvic inflammatory disease
• No ovulation or menstrual cycle
• Endometriosis
• Older than 40 years

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Infertility (cont.)

• Tests
• Semen analysis
• Monitoring of morning body temperature
• Blood hormone measurements
• Endometrial biopsy
• Urine analysis for LH
• Hysterosalpingogram
• Laparoscopy

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Infertility (cont.)

• Treatments
• Surgical repair of abnormalities
• Fertility drugs
• Hormone therapies
• Artificial insemination
• In vitro fertilization
• Use of surrogate

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Apply Your Knowledge
Indicate whether each cause of infertility is
male-related (M), female-related (F), or both (B).

• ___ Retrograde ejaculation
• ___ Mumps infection
• ___ Inadequate diet
• ___ Scarring from STDs

ANSWER

• ___ Pelvic inflammatory disease
• ___ Hormone imbalances
• ___ Use of some medications
• ___ Being over 40 years old

F
M
M
F
F
M
B
F
Very good!
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Sexually Transmitted Disease Infections Occurring
in Both Sexes
STD Cause
AIDS HIV virus causes AIDS
Chlamydia Caused by bacterium Chlamydia trachomata. most commonly reported often no symptoms in female
Genital warts Condyloma acuminat caused by HPV not everyone infected has symptoms
Gonorrhea Bacterial cause Neisseria gonorrhoea
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Sexually Transmitted Diseases (cont.)
STD Cause
Herpes simplex Viral cause type II commonly known as genital herpes
Pubic lice Parasitic infestation commonly called crabs Pediculosis pubis
Syphilis Bacterial cause Treponema pallidum decreasing in women but increasing in homosexual males
Trichomoniasis Protozoan Trichomonas vaginalis
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Apply Your Knowledge
SUPER!
Match ___ Most commonly reported STD in
the U.S. ___ Two types both caused by a
virus ___ Crabs ___ Increasing incidence in
males ___ Common bacterial STD can
also grow in mouth ___ Caused by HPV virus
ANSWER
D

1. Gonorrhea
2. Genital warts
3. Syphilis
4. Chlamydia
5. Pubic lice
6. Herpes simplex

F
E
C
A
B
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In Summary

• 32.1 The organs of the male reproductive system
  include the testes, responsible for sperm and
  hormone production the accessory organs of vas
  deferens, seminal vesicles, prostate, and
  bulbourethral glands scrotum and penis.
• 32.2 The diseases of the male reproductive
  system vary widely between simple inflammation
  and cancers.

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In Summary (cont.)

• 32.3 The organs of the female reproductive
  system include the ovaries, fallopian tubes,
  uterus, and vagina.
• The external accessory organs include the mons
  pubis, labia majora and minora, clitoris,
  urethral meatus, vaginal orifice, Bartholins
  glands, perineum, and mammary glands.
• 32.4 The diseases of the female reproductive
  system vary widely between simple inflammation
  and cancers.

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In Summary (cont.)

• 32.5 Fertilization occurs with the union of a
  sperm cell and an ovum, usually within the
  fallopian tubes.
• The fertilized ovum, now a blastocyst, implants
  in the endometrial wall of the uterus.
• The embryonic period occurs from week 2 through
  week 8 of the pregnancy the fetal period is
  from week 9 through delivery.

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In Summary (cont.)

• 32.6 The birth process ends pregnancy and
  occurs in three stages Dilation (effacement),
  expulsion (parturition), and placental stage
  (afterbirth).
• 32.7 Some of the contraceptive methods include
  coitus interruptus barrier methods chemical
  barriers oral contraceptives injectable,
  implantable, and insertable contraceptives
  and intrauterine devices.

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In Summary (cont.)

• 32.8 The causes of infertility are varied, with
  about 15 of infertility from unknown causes.
• There are a number of infertility tests and
  treatments the treatment plan depends on the
  reason for the infertility.
• 32.9 There are many sexually transmitted
  infections, all passed between sexual partners
  (both heterosexual and same-sex partners).

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End of Chapter 27
The reproduction of mankind is a great marvel and
mystery. Martin Luther