The Male Reproductive System
Male Reproductive System
VAS DEFERENS
URINARY BLADDER
PROSTATE GLAND
SEMINAL VESICLE
COWPER’S GLAND
(BULBOURETHRAL GLAND)
PENIS
EPIDIDYMIS
URETHRA
SCROTUM
TESTIS
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A GENERAL OVERVIEW FOR WHAT’S TO COME
Fill in the blanks….
MEIOSIS occurs in the __________
TESTES
 ________
producing sperm
with 23 CHROMOSOMES
___________. Each human sperm cell has
3
________
parts – a head, a middle region, and a
TAIL
_________.
The acrosome at the tip of the head
PENETRATE
EGG
enables sperm to _____________
the _______.
The
MITOCHONDRIA which
middle region contains the ______________,
produce energy. The tail, a long and slender FLAGELLUM
________,
moves the sperm.
Fill in the blanks cont…..
SCROTUM
 The testes are housed in the ____________.
From the
testes, sperm passes through the EPIDIDYMIS
_________, which is a
VAS DEFERENS
storage and maturation area, to the _______________
where they are housed until delivery. The PROSTATE
__________
GLAND
at the base of the urethra secretes a fluid that has a
stimulating effect on the sperm. During intercourse,
URETHRA
they travel to the ________________,
where the
reproductive and urinary tracts join, emptying
PENIS
through the ___________.
An adult male produces
SPERM
_________
continuously, several hundred million each
day of his life. Those that are not ejaculated from the
REABSORBED in a continual cycle of
body are _____________
renewal.
Human Male Testis
EPIDIDYMIS
VAS DEFERENS
(ductus deferens)
SEMINIFEROUS
TUBULE
Main
Diagram
ACROSOME
NUCLEUS (with 23 chromosomes)
H
U
M
A
N
MITOCHONDRIA
BODY
TAIL
M
A
L
E
S
P
E
R
M
MALE REPRODUCTIVE SYSTEM
 Major function is to produce a sperm cell
 Are not produced until the male reaches puberty
 PITUITARY GLAND
 Secretes a hormone to signal the testes to produce
testosterone
 Testosterone causes the testes to begin producing sperm
EXTERNAL MALE REPRODUCTIVE
ORGANS
 SCROTUM
 ANATOMY



Sac that hangs outside the body
Holds the testes
Changes to the color and texture take place as the male ages
External Male Repro. Cont…
 FUNCTION
 Protect testes
 Keeps testes at proper temperature for spermatogenesis



Spermatogenesis – producing sperm cells
 Testes need to be 3-4 F lower than normal body temp. (98.6F)
As body temp. rises, muscles of the scrotum lower the testes
away from the body
As body temp. drops, muscles of the scrotum contract to pull
the testes in close to the body.
TESTES
Seminiferous
tubules
 ANATOMY & PHYSIOLOGY
 Seminiferous Tubules




Long series of thread-like tubes packed in testes
Approximately 1000 tubes, each about 1-3 feet
long
Capable of producing billions of sperm
Produce about 500 million or more each day
Sperm Cell…
 Consists of 3 parts
 1. Head

Contains 23 chromosomes
 Acrosome – tip of head; contains enzymes
enabling sperm to penetrate the egg
 2. Middle Region

2.
Contains mitochondria which produce energy
 3. Tail

1.
Moves/propels the sperm
3.
Epididymis
Testes A & P cont….
 Epididymis
 “over the testis”
 Highly coiled structure located on the backside of each
testis
 Approximately 20’ in length
 Stores newly produced sperm
 Sperm continue to & finish maturing here
 64 days for sperm maturation
External Male Reproductive System Cont….
 Penis
 Tube-like organ that functions both in
sexual reproduction as well as elimination
of body wastes
 Flaccid –


(“FLA-ssid”); normal state of the penis
Soft and hangs down from the front of the
body
PENIS
 3 long cylinders of spongy tissue


Rich supply of blood vessels and nerves
Erect – blood fills the spaces to make the penis
enlarged & hard
 Erections result entirely from blood flow
What can cause an erection?
• Boys get erections for all kinds of reasons – they
might happen if you :
– Are thinking about something sexual
– When you wake in the morning and have to pee
– When you are relaxed
– When you are anxious or frightened
– For no reason at all
ERECTIONS & EJACULATIONS
 All males can have an
erection (regardless of age!)
Boys get their
first erections
before they are
born!
 In order for semen to leave the penis, it must
be erect
erections & ejaculations cont…
HOWEVER ! ! ! !
 Because the penis is erect, it does NOT
mean semen must leave the penis
 It will return to the flaccid state without
ejaculation
process of an erection cont…
 If no ejaculation occurs….
 The erection will go away; possibly leaving
the male with some discomfort  which
also will subside
 IS NOT HARMFUL TO THE MALE IN ANY WAY!
INTERNAL MALE cont…
 SEMEN
 Composed of…




1. sperm from vas deferens
2. fluid (to nourish sperm) from seminal vesicle
3. fluid (milky, protects sperm) from prostate gland
4. fluid (clear & sticky, cleans urethra) from cowper’s gland
INTERNAL MALE REPRODUCTIVE SYSTEM
 VAS DEFERENS
 2 long tubes (18”) that connects
the epididymis w/urethra
 Receive mature sperm from
epididymis.
VAS DEFERENS
 Lined with cilia to help move sperm through tube
 Loops over the pubic bone, around the bladder, and
through the prostate
INTERNAL MALE cont…
 SEMINAL VESICLES
 2 little pouches just above and on
either side of the prostate gland
 Secrete fluid that mixes with sperm.


Helps make the sperm mobile
Provides nourishment to the sperm
SEMINAL
VESICLE
INTERNAL MALE cont…
 PROSTATE GLAND
 Lies just below the bladder &
surrounds the urethra
 Secretes a milky, alkaline (base)
PROSTATE GLAND
fluid that mixes with sperm
 Major portion of semen
 Helps protect sperm by
neutralizes acidity of urethra &
vagina of female
INTERNAL MALE cont…
 COWPER’S GLAND
 2 pea-sized glands, lie just
below the prostate and
open into urethra
 Secrete a clear, sticky fluid


Cleanses the urethra of acid
from urine
Some may be released
before semen is released
 This ejaculate may contain
some sperm! Which can
cause pregnancy
COWPER’S GLAND
INTERNAL MALE cont…
 URETHRA
 Tube-like organ that travels through the
penis

Passageway for semen and urine

Can sperm & urine come out at the same
time - ?
 NO! muscles surround the urethra at the
base of the bladder
 Muscles contract to close off the bladder
if penis is erect/ejaculation is about to
occur
 Urine cannot leave through the urethra
when semen is leaving the body
URETHRA
back
CIRCUMCISION
 FORESKIN –
 Male babies are born with a fold of skin that covers the
end of the penis.
 CIRCUMCISION –
 Surgical removal of the foreskin

Not necessary for health reasons  customary tradition
Forceps grasp foreskin and clips
it down to the initial incision
Surgeon makes an incision
around the foreskin
sutures (stitches) the top edge
of the skin that covers the penis
and the mucus membrane
MALE REPRODUCTIVE CONCERNS
NOCTURNAL EMISSION
 at the start of puberty, hormones cause the glands to




begin producing fluids
Fluids build up in reproductive system
While asleep, penis becomes erect and male ejaculates
No warning, uncontrollable
May or may not be accompanied by a dream 
perfectly normal
HERNIA
 Pushing of a part of the body through the muscle wall
normally keeping it in
 Can occur in various parts of the body
 INGUINAL HERNIA




Weak spot in the abdominal wall near the top of the scrotum
Straining of the abdominal muscles can cause a tear at this
weak spot
Part of the intestine can push through into the scrotum
Correctable with surgery
Video
STERILITY
 Sperm of the male is weak, malformed, sparse or
nonexistent, or unable to join an ovum (egg)
 CAUSES
 Temperature changes
 Exposure to certain chemicals
 Smoking
 Mumps as an adult
 Untreated STDs
 Epididymis, vas deferens, or urethra not working
correctly
TESTICULAR CANCER
 1% of cancers in all men; most common cancer in men
ages 15-34
 SIGNS
 Slight enlargement of one of the testes and a change in
its consistency
 Small hard lump in the testicle
 Collection of blood or fluid in scrotum
 Possibly no pain


Dull ache in the lower abdomen and groin
Dragging or heaviness feeling
TESTICULAR CANCER CONT…
 Undescended or partially descended testicles are at a
higher risk of developing cancer


The testicles usually move down into the scrotum just before
or just after birth. An undescended testicle is one that did not
move down into the scrotum.
WHY COULD THIS BE A PROBLEM????

THINK TEMPERATURE
 Surgery at an early age can correct the problem
PROSTATE PROBLEMS CONT…
 PROSTATE CANCER
 Most common cancer in men after lung cancer
 Cancers usually occur in older men
 SIGNS
 Often no early symptoms
 Frequent urination
 Difficulty urinating
 Pain or burning when urinating
 Blood in urine
 Lingering pain in back, hips, or pelvis
 Preventable by doctor visits
 DRE – “digital rectal exam”
MALE REPRODUCTIVE HEALTH
 UNCIRCUMCISED PENIS
 Collection of dead cells and glandular secretions may get
trapped under fold of skin = smegma
 Perfect environment for bacteria to grow and cause infections
 Pull foreskin back to cleanse area
 TESTICULAR SELF-EXAMINATION
 3-minute monthly exam
 During or after warm bath – scrotum is relaxed and away from
body
 Check for hard lumps or nodules (like a popcorn kernel or
BB)
 GUEST SPEAKER FOR BOYS ON 2/5
TENTATIVE SCHEDULE
 REST OF TODAY
 REVIEW FOR TEST (CROSSWORDS - DUE TOMORROW)



NEED TO BE ABLE TO LABEL 3 DIAGRAMS
KNOW THE 4 COMPONENTS OF SEMEN
BE AWARE OF THE FUNCTIONS OF ALL ORGANS
 WEDNESDAY
 TEST