Transcript Figure 27.1 The Male Reproductive System, Part

Chapter 27
The Reproductive
System
Lecture Presentation by
Steven Bassett
Southeast Community College
© 2015 Pearson Education, Inc.
Introduction
• The reproductive system is designed to
perpetuate the species
• The male produces gametes called sperm cells
• The female produces gametes called ova
• The joining of a sperm cell and an ovum is
fertilization
• Fertilization results in the formation of a zygote
© 2015 Pearson Education, Inc.
Organization of the Reproductive System
• The reproductive system includes:
• Gonads
• Testes / Ovaries
• Reproductive tract
• Accessory glands
• Perineal structures
• External genitalia
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• Principal structures of the male reproductive
system are:
• External genitalia
• Scrotum
• Penis
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• Principal structures of the male reproductive
system are (continued):
•
•
•
•
•
•
•
•
Testis
Epididymis
Ductus deferens
Ejaculatory duct
Spongy urethra (penile urethra)
Seminal gland
Prostate gland
Bulbo-urethral gland
© 2015 Pearson Education, Inc.
Figure 27.1 The Male Reproductive System, Part I (1 of 2)
Prostatic urethra
Pubic symphysis
Major Components of the
Male Reproductive System
Ducts
Urinary
bladder
Ureter
Rectum
Ejaculatory duct
Accessory Glands
Membranous urethra
Seminal gland
Spongy urethra
Prostate gland
Bulbo-urethral gland
Ductus deferens
Epididymis
Gonad
Testis
Corpus cavernosum
External Genitalia
Penis
Corpus spongiosum
Scrotum
© 2015 Pearson Education, Inc.
External urethral orifice
Anus
Figure 27.1 The Male Reproductive System, Part I (2 of 2)
Sigmoid colon (cut)
Rectum
Rectus abdominis
Internal urethral orifice
Urinary bladder
Prostatic urethra
Prostate gland
Pubic symphysis
Bristle within
ejaculatory duct
Spongy urethra
within corpus
spongiosum
Membranous urethra
Spongy urethra
Penis
Bulbospongiosus
muscle
Corpus
cavernosum
Ductus deferens
Epididymis
Testis
© 2015 Pearson Education, Inc.
Scrotum
Anatomy of the Male Reproductive System
• The Testes
• Testes hang inside a pouch called the scrotum,
which is on the outside of the body
• Testicle size
•
•
•
•
5 cm long
3 cm wide
2.5 cm thick
10–15 g
© 2015 Pearson Education, Inc.
Figure 27.1 The Male Reproductive System, Part I (1 of 2)
Prostatic urethra
Pubic symphysis
Major Components of the
Male Reproductive System
Ducts
Urinary
bladder
Ureter
Rectum
Ejaculatory duct
Accessory Glands
Membranous urethra
Seminal gland
Spongy urethra
Prostate gland
Bulbo-urethral gland
Ductus deferens
Epididymis
Gonad
Testis
Corpus cavernosum
External Genitalia
Penis
Corpus spongiosum
Scrotum
© 2015 Pearson Education, Inc.
External urethral orifice
Anus
Anatomy of the Male Reproductive System
• Descent of the Testes
• During development, the testes form inside the
abdominal cavity near the kidneys
• Testes descend toward the scrotum by passing
through the inguinal canals
• The ductus deferens, blood vessels, lymphatics,
and nerves remain bundled to the testes in the
spermatic cords
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• Descent of the Testes
• Testicle development requires a temperature
approximately 98.6°F
• Hence the development of the testicles within the
abdominal cavity
• Sperm development requires a temperature
approximately 96.6°F
• Hence the development of sperm cells outside the
abdominal cavity
© 2015 Pearson Education, Inc.
Figure 27.2b The Descent of the Testes (1 of 2)
Diaphragmatic
ligament
Developing
kidneys
Gonads
Mesonephric
duct
Gubernaculum
testis
2 months
Kidney
Diaphragmatic
ligament
Epididymis
Testis
3 months
Epididymis
Testis
Urinary bladder
4 months
b Anterior views of the opened abdomen at
representative stages in the descent of the testes.
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• The Spermatic Cords
• Consist of:
•
•
•
•
•
•
•
Ilionguinal nerve
Genitofemoral nerve
Deferential artery
Ductus deferens
Pampiniform plexus
Testicular artery
Testicular vein
© 2015 Pearson Education, Inc.
Figure 27.3 The Male Reproductive System, Part II
Testicular artery
Urinary
bladder
Testicular vein
Penis
Inguinal
canal
Inguinal ligament
Spermatic Cord
Superficial
inguinal ring
Genitofemoral nerve
Deferential artery
Ductus deferens
Pampiniform plexus
Testicular artery
Epididymis
Spermatic cord
Scrotal septum
Cremaster muscle within
cremasteric fascia
Scrotal cavity
Testis (covered by visceral
layer of tunica vaginalis)
Parietal layer of
tunica vaginalis
(inner lining of cremaster,
facing scrotal cavity)
Perineal raphe
© 2015 Pearson Education, Inc.
Layers of the Scrotum
Superficial scrotal
fascia
Dartos muscle
Scrotal skin (cut)
Anatomy of the Male Reproductive System
• The Scrotum and the Position of the Testes
• Divided into two chambers (scrotal cavities)
• Chambers are separated by the perineal raphe
• Can be seen as thickened tissue that extends from
the anus, across the scrotum, and along the anterior
surface of the penis
• Tunica vaginalis
• A serous membrane that covers the outside of
each testis and covers the inside lining of each
scrotal cavity
© 2015 Pearson Education, Inc.
Figure 27.3 The Male Reproductive System, Part II
Testicular artery
Urinary
bladder
Testicular vein
Penis
Inguinal
canal
Inguinal ligament
Spermatic Cord
Superficial
inguinal ring
Genitofemoral nerve
Deferential artery
Ductus deferens
Pampiniform plexus
Testicular artery
Epididymis
Spermatic cord
Scrotal septum
Cremaster muscle within
cremasteric fascia
Scrotal cavity
Testis (covered by visceral
layer of tunica vaginalis)
Parietal layer of
tunica vaginalis
(inner lining of cremaster,
facing scrotal cavity)
Perineal raphe
© 2015 Pearson Education, Inc.
Layers of the Scrotum
Superficial scrotal
fascia
Dartos muscle
Scrotal skin (cut)
Anatomy of the Male Reproductive System
• The Scrotum and the Position of the Testes
(continued)
• Muscles of the scrotum
• Dartos muscle
• Contraction causes the wrinkling of the scrotal surface
• Cremaster muscle
• Contraction tenses the scrotal sac and pulls it closer to
the body
• The temperature for sperm development is 2°F cooler
than body temperature
• Therefore, if the temperature is cold outside, the
testes move closer to the abdomen to maintain the
proper temperature
© 2015 Pearson Education, Inc.
Figure 27.3 The Male Reproductive System, Part II
Testicular artery
Urinary
bladder
Testicular vein
Penis
Inguinal
canal
Inguinal ligament
Spermatic Cord
Superficial
inguinal ring
Genitofemoral nerve
Deferential artery
Ductus deferens
Pampiniform plexus
Testicular artery
Epididymis
Spermatic cord
Scrotal septum
Cremaster muscle within
cremasteric fascia
Scrotal cavity
Testis (covered by visceral
layer of tunica vaginalis)
Parietal layer of
tunica vaginalis
(inner lining of cremaster,
facing scrotal cavity)
Perineal raphe
© 2015 Pearson Education, Inc.
Layers of the Scrotum
Superficial scrotal
fascia
Dartos muscle
Scrotal skin (cut)
Anatomy of the Male Reproductive System
• The Scrotum and the Position of the Testes
(continued)
• The scrotum is highly vascularized by the:
• Internal pudendal arteries
• A branch from the internal iliac artery
• External pudendal arteries
• A branch from the femoral artery
• Inferior epigastric arteries
• A branch from the external iliac artery
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• The Scrotum and the Position of the Testes
(continued)
• The scrotum has nerves from the:
•
•
•
•
Hypogastric plexus
Ilioinguinal nerves
Genitofemoral nerves
Pudendal nerves
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• Structure of the Testes
• Tunica albuginea
•
•
•
•
A tough fibrous lining of the testes
Extends deep into the testes and forms septa
Septa converge toward the mediastinum
Mediastinum supports ducts that move material
toward the epididymis
• Tunica vaginalis
• Fibrous tissue that surrounds the tunica albuginea
and is continuous with the surrounding tissue of the
epididymis
© 2015 Pearson Education, Inc.
Figure 27.4a Structure of the Testes
Ductus deferens
Mediastinum of testis
Epididymis
Efferent ductule
Rete
testis
Scrotum
Skin
Dartos muscle
Straight
tubule
Superficial
scrotal fascia
Cremaster muscle
Seminiferous
tubules
Tunica vaginalis
Tunica albuginea
Septa
Scrotal cavity
Septa
Lobule
Perineal raphe
a Diagrammatic horizontal section
showing the anatomical relationships
of the testes within the scrotal
cavities. The connective tissues
surrounding the seminiferous tubules
and the rete testis are not shown.
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• Histology of the Testes
• The septa of the testes separate the testes into
lobules
• Each lobule contains seminiferous tubules
• Seminiferous tubules begin to uncoil leading to the
straight tubules in the mediastinum area
• The straight tubules interconnect with each other
forming the rete testis
• Rete testis connects to the efferent ductules
• Efferent ductules lead to the epididymis
© 2015 Pearson Education, Inc.
Figure 27.4a Structure of the Testes
Ductus deferens
Mediastinum of testis
Epididymis
Efferent ductule
Rete
testis
Scrotum
Skin
Dartos muscle
Straight
tubule
Superficial
scrotal fascia
Cremaster muscle
Seminiferous
tubules
Tunica vaginalis
Tunica albuginea
Septa
Scrotal cavity
Septa
Lobule
Perineal raphe
a Diagrammatic horizontal section
showing the anatomical relationships
of the testes within the scrotal
cavities. The connective tissues
surrounding the seminiferous tubules
and the rete testis are not shown.
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• Histology of the Testes (continued)
• There is a space between the coils of the
seminiferous tubules
• The cells within this space are the interstitial
cells
• Interstitial cells produce and release testosterone
© 2015 Pearson Education, Inc.
Figure 27.5ac Histology of the Seminiferous Tubules
Seminiferous tubule
containing late
spermatids
Seminiferous tubule
containing
spermatozoa
Seminiferous tubule
containing early
spermatids
LM × 75
Seminiferous tubules
a Seminiferous tubules in
sectional view
Interstitial
cells
Dividing
spermatocytes
Nurse cell
Spermatogonia
Spermatids
Lumen
Heads of
maturing
spermatozoa
Tubular
capsule
Seminiferous tubule
c Spermatogenesis within one
segment of a seminiferous tubule
© 2015 Pearson Education, Inc.
LM × 350
Anatomy of the Male Reproductive System
• Histology of the Testes (continued)
• Testosterone
•
•
•
•
•
•
Stimulates spermatogenesis
Promotes sperm maturation
Maintains the accessory organs
Develops secondary sex characteristics
Stimulates growth and development
Stimulates sexual behavior and sexual drive
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• Spermatogenesis and Meiosis
• Spermatogenesis
• Formation of sperm cells
• Meiosis
• Set of events involved in producing the sperm cells
• Meiosis begins in the outer layer of the
seminiferous tubules
• Spermatogonia
• Stem cells that will become sperm cells
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• Spermatogenesis and Meiosis (continued)
• At sexual maturation, spermatogonia divide
• One of the cells produced by this division remains
in the outer layer of the seminiferous tubules as a
stem cell
• The other cell produced by this division
differentiates to become a primary spermatocyte
• The primary spermatocyte begins to undergo
meiosis
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• Meiosis associated with the formation of sperm
cells is called spermatogenesis
• The primary spermatocyte undergoes division to
produce two secondary spermatocytes
• Each secondary spermatocyte undergoes meiosis
to produce four haploid spermatids
• Each spermatid matures to become a haploid
sperm cell
• Haploid sperm cells contain 23 chromosomes
© 2015 Pearson Education, Inc.
Figure 27.5b Histology of the Seminiferous Tubules
SPERMATOGENESIS
MITOSIS of
spermatogonium
(diploid)
Primary spermatocyte
(diploid)
DNA replication
Synapsis and
tetrad formation
Primary spermatocyte
Tetrad
MEIOSIS I
Secondary
spermatocytes
MEIOSIS II
Spermatids
(haploid)
SPERMIOGENESIS
(physical maturation)
Spermatozoa
(haploid)
b Meiosis in the testes showing the fates of three
representative chromosomes
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• Spermiogenesis
• Spermatids will mature to form a spermatozoon
(sperm cell)
• This maturation process is called
spermiogenesis
• While the spermatids are maturing, they become
embedded in nurse cells
• Upon maturation, the spermatids (now sperm cells)
enter into the lumen of the seminiferous tubules
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• Nurse Cells
• Function of Nurse Cells
•
•
•
•
Maintenance of the blood–testis barrier
Support of spermatogenesis
Support of spermiogenesis
Secretion of inhibin
• Controls the rate of sperm formation
• Secretion of androgen-binding protein (ABP)
• Binds testosterone within the seminiferous tubules
so testosterone will continue to have an effect on
spermiogenesis
© 2015 Pearson Education, Inc.
Figure 27.5cd Histology of the Seminiferous Tubules
Interstitial
cells
Dividing
spermatocytes
Nurse cell
Spermatids completing
spermiogenesis
Spermatogonia
Initial spermiogenesis
LUMEN
Spermatids beginning
spermiogenesis
Secondary
spermatocyte
Luminal compartment
Spermatids
Primary
spermatocyte
preparing
for meiosis I
Secondary spermatocyte
in meiosis II
Lumen
Level of
blood–testis
barrier
Heads of
maturing
spermatozoa
Nurse
cells
Fibrocyte
Tubular
capsule
Capillary
Tubular
capsule
Interstitial
cells
Seminiferous tubule
c Spermatogenesis within one
segment of a seminiferous tubule
© 2015 Pearson Education, Inc.
Spermatogonium
LM × 350
Basal compartment
d The blood–testis barrier and the structure of the wall
of a seminiferous tubule
Anatomy of the Male Reproductive System
• Anatomy of a Spermatozoon
• Each spermatozoon has three areas
• Head
• Contains chromosomes
• Contains acrosomal cap consisting of enzymes
• Enzyme, hyaluronidase, is necessary for
fertilization of the egg
• Middle piece (with the neck)
• Contains mitochondria
• Tail
• Called the flagellum
• Enables mobility of the sperm cell
© 2015 Pearson Education, Inc.
Figure 27.6b Spermiogenesis and Spermatozoon Histology
Spermatid
(week 1)
Mitochondria
Tail (55 µm)
Fibrous sheath
of flagellum
Nucleus
Shed
cytoplasm
Golgi
apparatus
Dense
fibers
Acrosomal
vesicle
Middle piece (5 µm)
Neck (1 µm)
Acrosomal
cap
Centrioles
Nucleus
b Differentiation of a spermatid into a spermatozoon
Mitochondrial
spiral
Acrosomal
cap
Head (5 µm)
Nucleus
Acrosomal cap
Spermatozoon
(week 5)
© 2015 Pearson Education, Inc.
Microtubules
Figure 27.6a Spermiogenesis and Spermatozoon Histology
Spermatozoa
a Histology of human spermatozoa
© 2015 Pearson Education, Inc.
SEM × 1688
Anatomy of the Male Reproductive System
• The Male Reproductive Tract
• Epididymis
• Ductus deferens
• Urethra
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• The Epididymis
• Sperm cells move from the seminiferous tubules
(via fluid movement) eventually to the epididymis
to mature a little longer
• The epididymis consists of three parts
• Head
• Receives spermatozoa via the efferent ducts
• Body
• Coiled tubes pass through the body
• Tail
• Tubes begin to uncoil to become a single tube called
the ductus deferens
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• Functions of the Epididymis
• Monitors the composition of the fluid in the
seminiferous tubules
• Recycling center for damaged spermatozoa
• Stores spermatozoa for further maturation (about
two weeks)
• Mature sperm cells are not active until they
become capacitated
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• Functions of the Epididymis (continued)
• The process of capacitation
• Sperm cells become motile when mixed with
secretions from the seminal glands
• Become capable of fertilizing an egg when
exposed to the female reproductive tract
© 2015 Pearson Education, Inc.
Figure 27.7a The Epididymis
Spermatic cord
Ductus deferens
The Epididymis
Head
Efferent ductules
Straight tubule
Rete testis in
mediastinum
Seminiferous
tubule
Body
Tunica albuginea
covering testis
Scrotal cavity
Tail
a Diagrammatic view of the testis and epididymis
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• The Ductus Deferens
• Also called the vas deferens
• Begins at the tail of the epididymis
• Ascends into the abdominal cavity through the
inguinal canal
• Curves around the urinary bladder and the ureter
• Descends back toward and through the prostate
gland
• Before entering the prostate gland, the ductus
deferens expands (ampulla) and becomes the
ejaculatory duct
• The ejaculatory duct enters the prostate gland
© 2015 Pearson Education, Inc.
Figure 27.1 The Male Reproductive System, Part I
Prostatic urethra
Pubic symphysis
Urinary
bladder
Major Components of the
Male Reproductive System
Ducts
Ureter
Rectum
Accessory Glands
Seminal gland
Ejaculatory duct
Membranous urethra
Spongy urethra
Prostate gland
Bulbo-urethral gland
Ductus deferens
Epididymis
Gonad
Testis
Corpus cavernosum
External Genitalia
Penis
Corpus spongiosum
Anus
External urethral orifice
Scrotum
Sigmoid colon (cut)
Rectum
Rectus abdominis
Internal urethral orifice
Urinary bladder
Prostatic urethra
Prostate gland
Pubic symphysis
Bristle within
ejaculatory duct
Spongy urethra
within corpus
spongiosum
Membranous urethra
Spongy urethra
Penis
Bulbospongiosus
muscle
Corpus
cavernosum
Ductus deferens
Epididymis
Testis
© 2015 Pearson Education, Inc.
Scrotum
Figure 27.8a The Ductus Deferens and Accessory Glands
a A posterior view of the urinary bladder and prostate gland showing
subdivisions of the ductus deferens in relation to surrounding structures.
Ureter
Urinary
bladder
Ductus deferens
Seminal gland
Ampulla of
ductus deferens
Duct of
seminal gland
Ejaculatory duct
Prostate gland
Prostatic urethra
Bulbo-urethral glands
Urogenital diaphragm
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• The Urethra
• Divided to form three regions
• Prostatic urethra
• Extends from the urinary bladder through the
prostate gland
• Membranous urethra
• The merging of the prostatic urethra and the
ejaculatory duct
• Spongy urethra
• Passes through the penis
• Sometimes called the penile urethra
© 2015 Pearson Education, Inc.
Figure 27.1 The Male Reproductive System, Part I
Prostatic urethra
Pubic symphysis
Urinary
bladder
Major Components of the
Male Reproductive System
Ducts
Ureter
Rectum
Accessory Glands
Seminal gland
Ejaculatory duct
Membranous urethra
Spongy urethra
Prostate gland
Bulbo-urethral gland
Ductus deferens
Epididymis
Gonad
Testis
Corpus cavernosum
External Genitalia
Penis
Corpus spongiosum
Anus
External urethral orifice
Scrotum
Sigmoid colon (cut)
Rectum
Rectus abdominis
Internal urethral orifice
Urinary bladder
Prostatic urethra
Prostate gland
Pubic symphysis
Bristle within
ejaculatory duct
Spongy urethra
within corpus
spongiosum
Membranous urethra
Spongy urethra
Penis
Bulbospongiosus
muscle
Corpus
cavernosum
Ductus deferens
Epididymis
Testis
© 2015 Pearson Education, Inc.
Scrotum
Anatomy of the Male Reproductive System
• The Accessory Glands
• There are three glands associated with the male
reproductive system
• Seminal glands (or seminal vesicles)
• Prostate gland
• Bulbo-urethral glands (or Cowper’s glands)
© 2015 Pearson Education, Inc.
Figure 27.1 The Male Reproductive System, Part I
Prostatic urethra
Pubic symphysis
Urinary
bladder
Major Components of the
Male Reproductive System
Ducts
Ureter
Rectum
Accessory Glands
Seminal gland
Ejaculatory duct
Membranous urethra
Spongy urethra
Prostate gland
Bulbo-urethral gland
Ductus deferens
Epididymis
Gonad
Testis
Corpus cavernosum
External Genitalia
Penis
Corpus spongiosum
Anus
External urethral orifice
Scrotum
Sigmoid colon (cut)
Rectum
Rectus abdominis
Internal urethral orifice
Urinary bladder
Prostatic urethra
Prostate gland
Pubic symphysis
Bristle within
ejaculatory duct
Spongy urethra
within corpus
spongiosum
Membranous urethra
Spongy urethra
Penis
Bulbospongiosus
muscle
Corpus
cavernosum
Ductus deferens
Epididymis
Testis
© 2015 Pearson Education, Inc.
Scrotum
Anatomy of the Male Reproductive System
• The Accessory Glands (continued)
• The seminal glands
• Produce 60 percent of the semen volume
• Seminal fluid consists of
• A high concentration of fructose
• Prostaglandins
• Clotting factors
• Contents empty into the ductus deferens
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• The Accessory Glands (continued)
• The prostate gland
•
•
•
•
Contents empty into the prostatic urethra
Produces 20–30 percent of the semen volume
Weakly acidic
Secretions consist of seminalplasmin
• This is an antibiotic believed to prevent UTIs in
males
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• The Accessory Glands (continued)
• The bulbo-urethral glands
•
•
•
•
Paired glands located at the base of the penis
Produces 5 percent of the semen volume
Contents empty into the spongy urethra
Secretions
• Consists of thick, sticky, alkaline mucus
• Neutralizes urinary acids that are remaining in the
urethra
• Provides lubrication for the tip of the penis
© 2015 Pearson Education, Inc.
Figure 27.1 The Male Reproductive System, Part I
Prostatic urethra
Pubic symphysis
Urinary
bladder
Major Components of the
Male Reproductive System
Ducts
Ureter
Rectum
Accessory Glands
Seminal gland
Ejaculatory duct
Membranous urethra
Spongy urethra
Prostate gland
Bulbo-urethral gland
Ductus deferens
Epididymis
Gonad
Testis
Corpus cavernosum
External Genitalia
Penis
Corpus spongiosum
Anus
External urethral orifice
Scrotum
Sigmoid colon (cut)
Rectum
Rectus abdominis
Internal urethral orifice
Urinary bladder
Prostatic urethra
Prostate gland
Pubic symphysis
Bristle within
ejaculatory duct
Spongy urethra
within corpus
spongiosum
Membranous urethra
Spongy urethra
Penis
Bulbospongiosus
muscle
Corpus
cavernosum
Ductus deferens
Epididymis
Testis
© 2015 Pearson Education, Inc.
Scrotum
Anatomy of the Male Reproductive System
• Semen
• Each ejaculation releases 2 to 5 ml of semen
• Ejaculate material consists of:
• Spermatozoa
• 20 million to 100 million per ml
• Seminal fluid
•
•
•
•
60 percent from the seminal vesicles
30 percent from the prostate
5 percent from the bulbo-urethral glands
5 percent from the epididymis
• Enzymes
• Dissolves vaginal mucus and acts as an antibiotic
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• The Penis
• Divided into three regions
• Root
• Attaches to the rami of the ischia
• Body
• Consists of erectile tissue
• Glans
• The expanded distal end of the penis
• Surrounds the external urethral orifice
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• The Penis
• Consists of three cylindrical columns of erectile
tissue and blood vessels
• Two corpora cavernosa
• One corpus spongiosum
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• The Penis
• The corpora cavernosa
• Deep artery of the penis is in the center of this
tissue
• Each corpus cavernosum extends posteriorly
forming a crus of the penis
• Each crus is bound to the ramus of the ischium
• The corpus spongiosum
• Consists of the spongy urethra
© 2015 Pearson Education, Inc.
Figure 27.9c The Penis
Pubic
symphysis
Membranous
urethra
Bulb of penis
Right crus
of penis
Body (shaft)
of penis
Ischial ramus
Erectile Tissue
Corpus spongiosum
Corpora cavernosa
Glans
External
urethral orifice
Scrotum
c Lateral and oblique view of the penis showing
the orientation of the erectile tissues
© 2015 Pearson Education, Inc.
Figure 27.9ab The Penis
Ureter
Trigone of urinary
bladder
Ductus deferens
Seminal gland
Prostate gland
Opening of
ejaculatory duct
Prostatic urethra
Dorsal blood vessels
Membranous urethra
Bulbo-urethral gland
Urogenital diaphragm
Crus (leg)
of penis
Bulb of penis
Opening from
bulbo-urethral gland
Dorsal artery (red),
vein (blue), and
nerve (yellow)
Corpora
cavernosa
Erectile Tissue
Corpus spongiosum
Corpora cavernosa
Deep artery
of penis
Collagenous
sheath
Spongy urethra
Spongy urethra
Glans
Prepuce
External urethral
orifice
a Frontal section showing the
structures of the penis
© 2015 Pearson Education, Inc.
Corpus
spongiosum
b Cross sections of the penis showing
the histological relation of the urethra
and three masses of erectile tissue
Penis
LM × 12
Anatomy of the Male Reproductive System
• Erection of the Penis
•
•
•
•
Parasympathetic nerves are activated
Smooth muscles in the arterial walls relax
Arterial vessels dilate
Arterial vessels and vascular channels within the
corpora cavernosa become engorged with blood
• Erection occurs
© 2015 Pearson Education, Inc.
Anatomy of the Male Reproductive System
• Semen Release and Ejaculation
• The sympathetic nerves cause peristaltic action in
the:
•
•
•
•
Ductus deferens
Seminal glands
Prostate gland
Bulbo-urethral glands
• Ejaculation occurs
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• Overview of the Female Reproductive System
•
•
•
•
•
Ovaries
Fimbriae
Uterine tubes
Uterus
Vagina
© 2015 Pearson Education, Inc.
Figure 27.10 The Female Reproductive System (1of 2)
Major Components
of the Female
Reproductive System
Ovarian follicle
Gonad
Ovary
Rectouterine
pouch
Vesicouterine
pouch
Uterine tube
Sigmoid
colon
Uterus
Perimetrium
Myometrium
Endometrium
Urinary bladder
Urethra
Cervix
Pubic symphysis
Vagina
Accessory Glands
Rectum
Paraurethral glands
Greater vestibular gland
Clitoris
© 2015 Pearson Education, Inc.
Anus
External Genitalia
Labium minus
Labium majus
Figure 27.10 The Female Reproductive System (2 of 2)
Suspensory ligament
of ovary
Uterine tube
Ovary
Fundus of uterus
Endometrium of uterus
Body of uterus
(myometrium)
Urinary bladder
Probe through internal
os of uterus
Cervix of uterus
Pubic symphysis
Urethra
Probe through external
os of uterus
Vagina
External urethral orifice
Rectum
Vestibule
Anus
Fat of mons pubis
Labium minus
Labium majus
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• Numerous structures aid in anchoring the ovaries,
uterine tubes, and uterus
•
•
•
•
•
•
•
Broad ligament
Mesosalpinx
Mesovarium
Ovarian ligament
Suspensory ligament
Round ligament
Uterosacral ligament
© 2015 Pearson Education, Inc.
Figure 27.11a The Ovaries, Uterine Tubes, and Uterus
Structures Stabilizing the Ovary
Fimbriae
Ovarian
ligament
Uterine tube
Mesovarium
Suspensory
ligament
Retractor
Ovarian artery
and vein
Uterus
Infundibulum
Broad ligament
Ovary
Ureter
Uterosacral ligament
External os
Cervix
Vaginal rugae
Vaginal wall
a Posterior view of the ovaries, uterine tubes, and
uterus along with their supporting ligaments.
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• The Ovaries
• Consist of:
• Cortex
• Gamete production occurs here
• Medulla
© 2015 Pearson Education, Inc.
Figure 27.11b The Ovaries, Uterine Tubes, and Uterus
Uterine tube
Ovarian
hilum
Medulla
Corpus
luteum
Cortex
Mesenteries Stabilizing the
Female Reproductive System
Tunica
albuginea
Mesosalpinx
Mesovarium
Broad ligament
Egg
nest
Germinal
epithelium
Mature
follicle
b The ovary and associated mesenteries in sectional view.
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• The Ovarian Cycle and Oogenesis
• Oogenesis is the production of female gametes
• Previous thoughts:
• Unlike the males, this process begins before birth
• Current research:
• This might not be the case
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• The Ovarian Cycle and Oogenesis (details)
• At puberty, the follicle-stimulating hormone
(FSH) from the pituitary gland initiates the cycle
• Primordial follicles develop into primary follicles
• During this development, several layers of cells
form around the follicles
• Zona pellucida
• This layer consists of granulosa cells
• These cells form interdigitating microvilli to the
oocyte
• These cells also produce estrogen
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• The Ovarian Cycle and Oogenesis (details)
• The layer surrounding the zona pellucida:
• Thecal cells
• These cells also release estrogen
• Estrogen functions
•
•
•
•
Stimulates bone and muscle growth
Maintains female secondary sex characteristics
Affects sex-related behaviors and drives
Maintains function of reproductive glands and
organs
• Initiates repair and growth of uterine lining
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• The Ovarian Cycle and Oogenesis (details)
• The primary follicles develop to form secondary
follicles
• Secondary follicles enlarge greatly due to fluid
production by the follicular cells
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• The Ovarian Cycle and Oogenesis (details)
• The secondary follicles become tertiary follicles
• This is the mature follicle (also called Graafian
follicle)
• This follicle is large enough to cause the ovarian
walls to stretch
• The tertiary follicle is preparing to ovulate the egg
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• The Ovarian Cycle and Oogenesis (details)
• Ovulation: gamete release
• The follicular cells around the oocyte are now
called the corona radiata
• There is a rise in the concentration of the
luteinizing hormone (LH)—this causes a
weakening in the follicular wall
• The egg is released eventually into the uterine
tube
© 2015 Pearson Education, Inc.
Figure 27.12 Histological Summary of the Ovarian Cycle (1 of 3)
Primordial Follicles
in Egg Nest
1
Formation of
Primary Follicles
LM × 1440
© 2015 Pearson Education, Inc.
Corona
radiata
Granulosa
cells
Thecal
cells
LM × 1092
Formation of
Tertiary Follicle
Granulosa
cells
Nucleus
of primary
oocyte
Zona
pellucida
3
Antrum
containing
follicular
fluid
Zona
pellucida
Primary
follicles
Follicle
cells
Formation of
Secondary Follicle
Thecal cells
Granulosa
cells
Primordial
oocyte
2
Secondary
oocyte
LM × 1052
LM × 136
Anatomy of the Female Reproductive
System
• The Ovarian Cycle and Oogenesis (details)
• After the release of the egg, the empty follicle is
called a corpus luteum
• The corpus luteum produces progesterone
• Progesterone is used to prepare the body for
pregnancy
• If pregnancy does not occur, the corpus luteum
decomposes (about 12 days after ovulation) and
becomes the corpus albicans
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• Age and Oogenesis
• At puberty, there are about 200,000 primordial
follicles per ovary
• Forty years later, only about 500 will have been
ovulated
• The rest decompose
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• The Uterine Tubes
• Consist of four regions
•
•
•
•
Infundibulum
Ampulla
Isthmus
Uterine part
© 2015 Pearson Education, Inc.
Figure 27.14a The Uterine Tubes
Ampulla
Isthmus
Infundibulum
Uterus
a Regions of
the uterine
tubes
© 2015 Pearson Education, Inc.
Fimbria
Anatomy of the Female Reproductive
System
• Four Regions of the Uterine Tubes
• Infundibulum
• Has numerous fimbriae
• Inner lining of infundibulum contains cilia
• Ampulla
• Isthmus
• Uterine part
• Opens into the uterus
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• Histology of the Uterine Tube
• Consists of
• Ciliated and nonciliated columnar cells
• Layers of smooth muscle
• Used for peristaltic action
• Successful fertilization
• Occurs 12–24 hours after ovulation
• Occurs in the distal 2/3 of the uterine tube (ampulla
region)
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• The Uterus
• Provides protection for the embryo
• Provides nutritional support for the embryo
• Provides a means to remove waste produced by
the embryo
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• The Uterus
• Overall size
•
•
•
•
Pear-shaped
7.5 cm long
5 cm diameter
30–40 g
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• Suspensory Ligaments of the Uterus
• These are in addition to the various regions of the
broad ligament
• Uterosacral ligaments
• Round ligaments
• Cardinal ligaments
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• Suspensory Ligaments of the Uterus
• Position of the suspensory ligaments
• Uterosacral ligaments
• Extend from the lateral edge of the uterus to the
anterior face of the sacrum
• Round ligaments
• Extend from the lateral edge of the uterus just
inferior to the base of the uterine tubes, pass
through the inguinal canal to the connective tissue
of the external genitalia
• Cardinal ligaments
• Extend from the base of the uterus and vagina to
the lateral walls of the pelvis
© 2015 Pearson Education, Inc.
Figure 27.11c The Ovaries, Uterine Tubes, and Uterus
Mesovarium
Rectouterine
pouch
POSTERIOR
Supporting Ligaments
of Uterus and Ovaries
Sigmoid colon
POSTERIOR
Uterosacral ligament
Uterine Tube
Suspensory ligament
of ovary
Infundibulum
Cardinal ligaments
(under broad ligament)
Ovary
Ovarian ligament
Uterus
Round ligament
of uterus
Urinary bladder
ANTERIOR
Ampulla
Isthmus
Fundus of uterus
Vesicouterine
pouch
ANTERIOR
c Superior view of the female pelvic cavity showing supporting ligaments of uterus and ovaries.
In the photo, the urinary bladder cannot be seen because it is covered by peritoneum.
© 2015 Pearson Education, Inc.
Ovary
Ovarian
ligament
Anatomy of the Female Reproductive
System
• Internal Anatomy of the Uterus
• Consists of:
•
•
•
•
•
•
•
Body
Fundus
Cervix
External os
Cervical canal
Uterine cavity
Internal os
© 2015 Pearson Education, Inc.
Figure 27.15a The Uterus
Uterine Tube
Fimbriae Infundibulum Ampulla
Isthmus
Uterine part
Uterine
tube
Fundus
of uterus
Suspensory ligament
of ovary
Ovarian artery
and vein
Mesovarium
Body of
uterus
Ovary
Ovarian ligament
Perimetrium
Myometrium
Uterine
cavity
Broad ligament
Endometrium
See Figure 27.16
Uterine artery
and vein
Internal os (internal orifice)
Isthmus of uterus
Cervix
Cervical canal
Vaginal artery
External os
(external orifice)
Vaginal rugae
See Figure 27.19
Vagina
a Posterior view of the uterus
and stabilizing ligaments
within the pelvic cavity
© 2015 Pearson Education, Inc.
Round ligament
of uterus
Anatomy of the Female Reproductive
System
• The Uterine Wall
• The uterine wall consists of three layers
• Endometrium
• Myometrium
• Consists of longitudinal, circular, and oblique
smooth muscles
• Perimetrium
© 2015 Pearson Education, Inc.
Figure 27.15a The Uterus
Uterine Tube
Fimbriae Infundibulum Ampulla
Isthmus
Uterine part
Uterine
tube
Fundus
of uterus
Suspensory ligament
of ovary
Ovarian artery
and vein
Mesovarium
Body of
uterus
Ovary
Ovarian ligament
Perimetrium
Myometrium
Uterine
cavity
Broad ligament
Endometrium
See Figure 27.16
Uterine artery
and vein
Internal os (internal orifice)
Isthmus of uterus
Cervix
Cervical canal
Vaginal artery
External os
(external orifice)
Vaginal rugae
See Figure 27.19
Vagina
a Posterior view of the uterus
and stabilizing ligaments
within the pelvic cavity
© 2015 Pearson Education, Inc.
Round ligament
of uterus
Anatomy of the Female Reproductive
System
• Blood Supply to the Uterus
• Uterine arteries arise from the internal iliac arteries
• Ovarian arteries arise from the abdominal aorta
inferior to the renal arteries
© 2015 Pearson Education, Inc.
Figure 27.15a The Uterus
Uterine Tube
Fimbriae Infundibulum Ampulla
Isthmus
Uterine part
Uterine
tube
Fundus
of uterus
Suspensory ligament
of ovary
Ovarian artery
and vein
Mesovarium
Body of
uterus
Ovary
Ovarian ligament
Perimetrium
Myometrium
Uterine
cavity
Broad ligament
Endometrium
See Figure 27.16
Uterine artery
and vein
Internal os (internal orifice)
Isthmus of uterus
Cervix
Cervical canal
Vaginal artery
External os
(external orifice)
Vaginal rugae
See Figure 27.19
Vagina
a Posterior view of the uterus
and stabilizing ligaments
within the pelvic cavity
© 2015 Pearson Education, Inc.
Round ligament
of uterus
Anatomy of the Female Reproductive
System
• Histology of the Uterus
• The endometrium is subdivided
• Functional layer
• This layer is closest to the uterine cavity
• Contains uterine glands
• Undergoes cyclic changes due to hormones
• Basilar layer
• This layer is closest to the myometrium
• Remains relatively constant
© 2015 Pearson Education, Inc.
Figure 27.16 The Uterine Wall
Uterine
cavity
Endometrium
Myometrium Perimetrium
Myometrium
Straight artery
Uterine cavity
Radial artery
Endometrium
Simple columnar
epithelium
Spiral artery
Functional layer
Arcuate
artery
Basilar layer
Uterine glands
Uterine
artery
a A diagrammatic sectional view
of the uterine wall
© 2015 Pearson Education, Inc.
Uterine wall
b A Sectional view of the
endometrium and its arterial
supply
LM × 32
c Basic histology of the
uterine wall
Anatomy of the Female Reproductive
System
• The Uterine Cycle
• The uterine cycle is the menstrual cycle
• Consists of three phases
• Proliferative phase
• Secretory phase
• Menses
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• Phases of the Uterine Cycle
• Menarche
• This is the first uterine cycle at puberty
• Proliferative phase
• Endometrial lining thickens preparing the body for
the implantation of a fertilized egg
• Secretory phase
• Endometrial glands enlarge and blood vessels
elongate
• An egg is ready to implant (if an egg is present)
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• Phases of the Uterine Cycle
• Menses
• Begins due to a decrease in progestin and
estrogen levels
• This causes constriction of blood vessels
• This causes a loss of the excess endometrial cells
• This is menstruation
• Menopause
• The last uterine cycle
© 2015 Pearson Education, Inc.
Figure 27.17a Histological Changes in the Uterine Cycle
Perimetrium
Endometrium
Myometrium
Cervix
Uterine
glands
Menses
a Menses.
© 2015 Pearson Education, Inc.
UTERINE CAVITY
LM × 63
Figure 27.17b Histological Changes in the Uterine Cycle
Uterine
cavity
Myometrium
Uterine
glands
UTERINE CAVITY
Proliferative phase
b Proliferative phase.
© 2015 Pearson Education, Inc.
LM × 66
Figure 27.17c Histological Changes in the Uterine Cycle
Secretory phase
LM × 52
c Secretory phase. The functional layer
is now so thick that at a magnification
comparable to that of part (a) or part
(b) you cannot capture the entire width
of the endometrium in one image.
© 2015 Pearson Education, Inc.
Figure 27.17d Histological Changes in the Uterine Cycle
Uterine
glands
UTERINE CAVITY
Uterine glands
LM × 150
d Detail of uterine glands.
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• The Vagina
• Extends from the cervix of the uterus to the
external genitalia
• Vagina is approximately 7.5–9 cm in length
• Cervix projects from the uterus into the vaginal
canal
• The edges of the cervix form recesses called the
fornix
• The urethra, vaginal canal, and rectum are in
close proximity to each other
© 2015 Pearson Education, Inc.
Figure 27.10 The Female Reproductive System (1of 2)
Major Components
of the Female
Reproductive System
Ovarian follicle
Gonad
Ovary
Rectouterine
pouch
Vesicouterine
pouch
Uterine tube
Sigmoid
colon
Uterus
Perimetrium
Myometrium
Endometrium
Urinary bladder
Urethra
Cervix
Pubic symphysis
Vagina
Accessory Glands
Rectum
Paraurethral glands
Greater vestibular gland
Clitoris
© 2015 Pearson Education, Inc.
Anus
External Genitalia
Labium minus
Labium majus
Anatomy of the Female Reproductive
System
• The Vagina
• Serves three major functions
• Passageway for elimination of menstrual fluids
• Receives the penis and holds spermatozoa before
they enter the uterus
• Serves as a passageway for the fetus during
vaginal birth
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• The Vagina
• Contains a normal population of bacteria
• Bacteria are provided nutrients found in the
cervical mucus
• The bacteria create an acid environment
• This reduces the growth of many pathogenic
organisms
• This also reduces sperm mobility
• Buffers found in seminal fluid counteract this acidity
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• Histology of the Vagina
• Lined with stratified squamous epithelium
• When relaxed, this tissue forms rugae
• Lamina propria is thick and elastic
• The muscular layer is continuous with the
myometrium of the uterus
© 2015 Pearson Education, Inc.
Figure 27.19 Histology of the Vaginal Wall
Stratified squamous
epithelium
(nonkeritinized)
Fornix
Vaginal
artery
Blood vessels
Lamina propria
Vaginal vein
Rugae
Hymen
Vaginal
canal
Greater vestibular
gland
Labia minora
© 2015 Pearson Education, Inc.
Lumen of
vaginal canal
Bundles of smooth
muscle fibers
Vestibule
The vaginal wall
LM × 27
Anatomy of the Female Reproductive
System
• The External Genitalia
•
•
•
•
•
•
•
•
Vulva
Vestibule
Labia minora
Clitoris
Prepuce
Labia majora
Mons pubis
Hymen (when present)
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• The External Genitalia (details)
• Vulva
• The entire genitalia area
• Vestibule
• The opening into the vagina surrounded by the
labia minora
• Clitoris
• Contains erectile tissue
• Labia majora and mons pubis
• Forms the lateral and superior edges of the
vestibule
© 2015 Pearson Education, Inc.
Figure 27.20a The Female External Genitalia
External
Genitalia
Mons pubis
Clitoris
Prepuce
Glans
Urethral opening
Vestibule
Vestibular bulb
Labium minora
Vaginal entrance
Hymen (torn)
Labium majora
Greater vestibular
gland
Anus
a An inferior view of the female perineum
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• The Mammary Glands
• Consist of:
• Lobes of mammary glands
• Milk leaves the lobes
• Lactiferous ducts
• Ducts lead to the nipple
• Nipple
• Areola
• Suspensory ligaments
© 2015 Pearson Education, Inc.
Figure 27.21a The Mammary Glands
Pectoralis major muscle
Pectoral fat pad
Suspensory ligaments
Lobules of mammary glands
Lactiferous duct
Areola
Nipple
Lactiferous sinus
a Gross anatomy of the breast
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• Development of the Mammary Glands during
Pregnancy
• Mammary gland ducts become mitotically active
• Due to:
• PRL / GH / HPL
• Fully developed by 6 months of pregnancy
• Milk is release when the infant sucks on the nipple
• Pressure from nursing causes the release of
oxytocin (OT) from the pituitary gland
• OT causes the contraction of the lactiferous ducts,
thus ejecting milk
© 2015 Pearson Education, Inc.
Figure 27.21c The Mammary Glands
Secretory alveoli
Lactiferous duct
Connective tissue
Resting mammary gland LM × 100
c Histology of a resting mammary gland
© 2015 Pearson Education, Inc.
Figure 27.21d The Mammary Glands
Duct of compound
tubuloalveolar gland
Connective tissue
Lactiferous duct
Milk
Secretory alveoli
Active mammary gland
LM × 100
d Histology of an active mammary gland
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• Pregnancy and the Female Reproductive System
• Upon fertilization of the egg, changes occur
• Blastocyst forms
• Eventually implants in the endometrial lining
• A placenta will form
• Placenta releases HCG
• HCG keeps the corpus luteum active
• An active corpus luteum maintains a thick
endometrial lining
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• Pregnancy and the Female Reproductive System
(continued)
• In three months, the corpus luteum will
decompose
• A thick endometrial lining will continue due to:
• The placenta produces progesterone, which
maintains the thick endometrial lining
• Placenta also produces
• Relaxin
• Human placental lactogen
© 2015 Pearson Education, Inc.
Anatomy of the Female Reproductive
System
• Pregnancy and the Female Reproductive System
(continued)
• Relaxin
• Increases pelvic flexibility during delivery
• Dilation of the cervix during birth
• Human placental lactogen
• Helps prepare the mammary glands for milk
production
© 2015 Pearson Education, Inc.
Aging and the Reproductive System
• Menopause
• Decline in estrogen levels results in:
•
•
•
•
Reduced size of the uterus
Reduced size of the breasts
Thinning of the vaginal walls
Weakening of the supportive tissues of the
reproductive organs
• Osteoporosis
• Hot flashes
• Typically occurs at age 45–55
© 2015 Pearson Education, Inc.
Aging and the Reproductive System
• The Male Climacteric
• Testosterone levels begin to decline (not as rapidly
as estrogen however)
• Occurs gradually between ages 50 and 60
• Reduction in sexual activity
© 2015 Pearson Education, Inc.