This document provides an overview of the male reproductive system. It describes both the external structures, which include the penis and scrotum, and the internal structures, which are the testes, epididymis, vas deferens, and accessory sex glands including the seminal vesicles, prostate gland, and bulbourethral glands. The testes produce both sperm and the hormone testosterone. Sperm mature as they pass through the epididymis and are stored in the vas deferens until ejaculation. The accessory glands secrete fluids that nourish the sperm and form the bulk of the semen.

1. Sarita Sharma
Assistant Professor
Department of Pharmacology
Mumbai

4. Anatomy of the Male Reproductive System
External genitalia (can be seen on the body surface)
 penis
 Scrotum
Internal genitalia (can’t be seen on the body surface)
 sperm producing organs
 testes
 ducts that move sperm from the testes out of the body
 epididymis
 vas (ductus) deferens
 Urethra
 exocrine glands (ACCESSORY SEX GLANDS) that secrete fluids
into the ducts adding to the sperm to make semen
 seminal vesicles
 prostate gland
 bulbourethral (Cowper’s) gland

5. MALEREPRODUCTIVEORGANS
External Genital
Organs
1. Penis
2. Scrotum
 InternalGenital
Organs
1. Testis
2. Epididymis
3. VasDeferens
4. Accessory Glands
a. Seminal Vesicles
b. Prostate Gland
c. Bulbourethral Glands

6. 1. Penis
 External penis consists of:
 a shaft
 a glans penis-
 a prepuce (foreskin) covers the glans
 Internal penis consists of:
 the urethra :transports urine and semen out of the
body .
 three cylindrical bodies of erectile tissue, a spongy network of
vascular spaces which fill with blood during sexual excitement.
 Corpora cavernosa : paired erectile bodies dorsal to
the urethra which are responsible for erection .
 Corpus spongiosum :surrounds the urethra and
prevents the collapse of the urethra during erection.

7. Penis

8. 2. Scrotum
 Sac of skin and muscle that hangs outside the abdominal
cavity which hold the testes
 Its external positioning keeps the testes at 34C which is
required for sperm production
 Two sets of muscles maintain testicular temperature:
 dartos
 a layer of smooth muscle deep to the skin
 cremaster
 smooth muscle surrounding the testes
 Contraction/relaxation of both muscles raise/lower the
testes toward/away from the abdominal cavity
increasing/decreasing testicular temperature

10. 1. Testis
2. Epididymis
3. VasDeferens
4. Accessory Glands
a. Seminal Vesicles
b. Prostate Gland
c. BulbourethralGlands

11. 1.Testes
 Organs responsible for the production of:
 male sex steroid hormone testosterone
 Sperm
 Organized into hundreds of sperm producing
seminiferous tubules
 the tubules are made of a simple columnar epithelium of
sertoli (Nurse) cells
 the sperm development (spermatogenesis) occurs between
sertoli cells from the basal surface (inside the body) of the
seminiferous tubule to the lumen (outside the body)
 Interstitial (Leydig) cells found between adjacent
seminiferous tubules synthesize testosterone
 Fluid within the seminiferous tubules flows toward the
epididymis carrying the sperm

12. Testes

13. Seminiferous Tubule

14. 2. Epididymis
 A mass of coiled tubes on the superficial surface of each
testis that the sperm must pass through prior to
ejaculation
 Sperm become mature (capable of fertilizing an ovum)
as pass through its tubes toward the vas deferens
 During ejaculation, a layer
of smooth muscle that
surrounds the distal
epididymis contracts,
expelling sperm into the
vas deferens

15. Epididymis
 Consists of tightly coiled ductus epididymis
 Stereocilia are microvilli that reabsorb
degenerated sperm
 Site of sperm maturation – acquire motility
and ability to fertilize
 Can store sperm for several months
 Continues as ductus (vas) deferens

16. The vas deferens is a thin tube that
starts from the epididymis to the
urethra in the penis.
Conveys sperm during sexual arousal
through peristaltic contractions
 Can also store sperm several months
3.VasDeferens(DuctusDeferens)

17. a. SeminalVesicles
b. ProstateGland
c. Bulbourethral Glands
Theseglands produce
nourishing fluids for the
sperms that enter the
urethra.
4. Accessoryglands(secrete most of
liquid portion of semen)

18. a.SeminalVesicles
TheSeminal Vesiclesare
sac-like structures attached
to the vasdeferens at one
side of the bladder.
Theyproduce asticky
yellowish fluid that
contains fructose.

20. b. ProstateGland
TheProstate Gland
surrounds the ejaculatory
ducts at the baseof the
urethra, just below the
bladder.
TheProstate Gland is
responsible for making the
production of semen, aliquid
mixture of sperm cells,
prostate fluid and seminal
fluid.

21. c. Bulbourethral Glands((Cowper’s Glands))
TheBulbourethral Glands are
two small glands located on the
sidesofthe urethra just below
the prostate gland.
Theseglandsproducea clear,slippery
fluid that empties directly intothe
urethra.
2 pea-sized glands inferior to the prostate
Produce thick, clear mucus during erection which:
neutralizes traces of acidic urine in the urethra
lubricates the urethra to facilitate the ejaculation of semen