The document summarizes the male reproductive system. It describes the internal organs including the testes, epididymis, vas deferens, seminal vesicles and prostate glands. It also describes the external organs of the penis and scrotum. It explains spermatogenesis, the process by which sperm are produced in the testes over 74 days. Key hormones such as FSH, LH and testosterone regulate and stimulate spermatogenesis. Semen is the fluid that contains sperm and secretions from glands that help nourish and transport sperm.

1. Physiology of
Reproductive System
Prepared by: Dr. R.K. Verma
Dr. Abdul Majid

2. Male Reproductive Organs

3. Male Reproductive System
 Internal Organs
1) Testes
2) Epididymis
3) Vas Deferens
4) Ejaculatory Duct
5) Seminal Vesicle
6) Prostate Glands
7) Cowper’s Gland
•External Organs
1. Penis
2. Scrotum

4. External Organs
 1.) PENIS - male organ of copulation and urina
 Parts:
 A). shaft/ body
 B). Glans penis – enlarged end; most sensitive
 C). Prepuce/foreskin – fold of retractable skin
covering the
 glans and is removed during circumcision
 - if it can not be retracted: phimosis
 D). urethral meatus – slit like opening located at
the tip of the penis; passageway for both semen
and urine

5. External Organs
2.) SCROTUM – saclike structure containing the
testes
darker coloration than the rest of the body covered
with sparse hair and wrinkled
environmental temperature affects the scrotum: too
hot---the dartos muscle relaxes and the testes hangs
or descend away from the body
too cold ----- the testes contracts and pull closer to
the body
spermatogenesis is affected by extremes of
temperature
testosterone production is not affected

6. Internal Organs
1.) TESTES – oval shaped
glandular organ lying within the
abdominal cavity in early fetal life
and descend in the scrotum after 28
weeks gestation undescended testes
/cryptorchidism
Functions:
1.Hormone production – testosterone
that stimulates spermatogenesis and
responsible for the secondary males
characteristics
2.Spematogenesis – production and
maturation of sperm cells; begins in
puberty

7. 1) Testes
Parts of the testes:
1)seminiferous tubules – long coiled tubes where
spermatogenesis takes place
2)Leydig/interstitial cells – produce testosterone
3)Sertoli cells – supporting cells which play a role in
sperm transport

8. 2) Epididymis
 long coiled tube approximately 20 feet long;
 where sperm travels for 12- 20 days
 takes 64 days for the sperm cells to mature;
rationale why therapy for azoospermia and
oligospermia becomes effective only after 2
months
 epididymitis – inflammation of the epididymis
3) Vas Deferens
passageway of the sperm cells from the epididymis;
contractile power of this area propels the spermatozoa to
the urethra during ejaculation
cut during vasectomy

9. 4) Ejaculatory Duct
passageway
for the semen

10. 6) Prostate Gland
walnut shaped body lying below the bladder
Surrounds the urethra and the 2 ejaculatory ducts
5) Seminal Vesicle
a pouch like organ lying behind the bladder and in front
of the rectum

11. 7) Cowper’s Gland
 located behind the prostate gland
 secretes an alkaline secretions that helps to
neutralize the acidic nature of the urethra and
provides lubrication during intercourse
 Bulbourethral Glands

12. SEMEN
seminal fluid
an organic fluid that may contain spermatozoa
it contains fructose and other elements of seminal fluids that
promote survival of the spermatozoa and provide a medium
through which spermatozoa can move or swim
Seminal fluid a mixture of secretions from:
1.Ejaculatory ducts
2.Seminal Vesicles
3.Prostate glands
4.Cowpers Gland
Semen Color: Translucent with white, grey or yellowish tint;
if reddish: hematospermia

13. Seminal Fluid
 Semen Quality: measured by its
ability to
 accomplished fertilization
 Normal volume : 2-5ml/ejaculation
100 million sperm cells/ml
 a sperm count of below 20 million is
associated with infertility and
 sterility

14. Spermatozoa

15. GAMETOGENIC FUNCTIONS
OF TESTES – SPERMATOGENESIS
Spermatogenesis is the process by which the male
gametes called spermatozoa (sperms) are formed from
the primitive spermatogenic cells (spermatogonia) in
the testis
It takes 74 days for the formation of sperm from a primitive
germ cell. Throughout the process of spermatogenesis, the
spermatogenic cells have cytoplasmic attachment with
Sertoli cells.
Sertoli cells supply all the necessary materials for
spermatogenesis through the cytoplasmic attachment.

16. „STAGES OF SPERMATOGENESIS
Spermatogenesis occurs in four stages:
1. Stage of proliferation
2. Stage of growth
3. Stage of maturation
4. Stage of transformation

17. Spermatogenesis. Number in parenthesis indicate chromosomal number

19. Blue arrow = Stimulation,
Red dotted arrow =
inhibition,
GnRH =
Gonadotropin-releasing
hormone,
FSH = Follicle-stimulating
hormone,
LH = Lutinizing hormone,
GH = Growth hormone
Role of hormones in
spermatogenesis