- The male reproductive system includes the penis, testes, scrotum, prostate gland, and other structures. The testes produce sperm and hormones within the scrotum, which provides a cooler environment for sperm production. The prostate gland secretes fluids that protect and nourish sperm. - The testes and epididymis work together to produce, mature, and store sperm. The epididymis is a coiled tube that receives sperm from the testes and stores it until ejaculation. The testes have seminiferous tubules where sperm are produced with help from Sertoli cells. - The scrotum houses the testes and epididymis and contains muscles that help

1. THE MALE
REPRODUCTIVE SYSTEM

2. SUMMARY
• The male reproductive system mainly resides within the pelvis. Some tissues sit
outside of the pelvis, in the scrotum, which provides a cooler environment. The male
reproductive system can be split into seven parts: the penis, the testes and
epididymis, the scrotum, the spermatic cord, the prostate gland, the bulbourethral
glands and the seminal vesicles.
• The penis has three main anatomical sections: the root (where the penis is fixed to
the pelvic floor), the body (the length of the penis) and the glans (where the urethral
opening is located).
• The testes and epididymis are located in the scrotum, suspended by the spermatic
cord. This is the location of sperm production, maturation and storage.

3. • The scrotum is a fibromuscular sac located posteriorly to the penis. The dartos
muscle is located deep to the skin and helps adjust the surface area of the
scrotum, and therefore its internal temperature.
• The spermatic cord is a collection of blood vessels, nerves and ducts that connect
the testes to the pelvic cavity. Many important structures run in this bundle,
including the testicular artery, pampiniform plexus of testicular veins and vas
deferens.

4. • The prostate gland sits inferiorly to the bladder. It secretes enzymes into the semen
which maintain the semen’s fluid state. These enzymes enter the prostatic urethra via
the prostatic ducts. The prostate’s anatomy consists of three zones, the central,
transitional and peripheral zones, where different pathologies arise.
• The bulbourethral glands, or Cowper’s glands, are located posterolaterally to the
membranous urethra. They produce a mucus secretion which serves as lubrication,
expels any urine residue from the urethra and neutralises residual acidity within the
urethra.
• The seminal vesicles sit superiorly to the prostate, and drain a fructose-rich alkaline
fluid into the prostatic urethra.

5. THE TESTES AND EPIDIDYMIS
• The testes and epididymis are paired structures, located within the scrotum. The
testes are the site of sperm production and hormone synthesis, while the
epididymis has a role in the storage o f sperm.
• The testes are located within the scrotum, with the epididymis situated on the
posterolateral aspect of each testicle. Commonly, the left testicle lies lower than
the right. They are suspended from the abdomen by the spermatic cord –
collection of vessels, nerves and ducts that supply the testes.

7. THE TESTES
• The testes consist of a series of lobules, each containing seminiferous tubules
• The seminiferous tubules are supported by interstitial tissue and are lined by
Sertoli cells.
• Sertoli cells aid the maturation process of the spermatozoa.
• In the interstitial tissue lie the Leydig cells that are responsible for testosterone
production.
• Inside the scrotum, the testes are covered almost entirely by the tunica vaginalis, a
closed sac of parietal peritoneal origin that contains a small amount of viscous fluid.
This sac covers the anterior surface and sides of each testicle and works much like
the peritoneal sac, lubricating the surfaces of the testes and allowing for friction-
free movement.

8. THE EPIDIDYMIS
• The epididymis consists of a single heavily coiled duct. It can be divided into
three parts; head, body and tail.
• Head – The most proximal part of the epididymis. It is formed by the efferent
tubules of the testes, which transport sperm from the testes to the epididymis.
• Body – Formed by the heavily coiled duct of the epididymis.
• Tail – The most distal part of the epididymis. It marks the origin of the vas
deferens, which transports sperm to the prostatic portion of the urethra for
ejaculation.

10. Innervation
• The testes and epididymis receive innervation from the testicular plexus – a
network of nerves derived from the renal and aortic plexi. They receive autonomic
autonomic and sensory fibres.

11. Vascular Supply
• The main arterial supply to the testes and epididymis is via the paired testicular
arteries, which arise directly from the abdominal aorta.
• Venous drainage is achieved via the paired testicular veins. They are formed from
the pampiniform plexus in the scrotum – a network of veins wrapped around the
the testicular artery. In the retroperitoneal space of the abdomen, the left
testicular vein drains into the left renal vein, while the right testicular vein drains
directly into the inferior vena cava.

12. Pampiniform plexus

13. Lymphatics
• Since the testes are originally retroperitoneal organs, the lymphatic drainage is to
the lumbar and para-aortic nodes, along the lumbar vertebrae.
• This is in contrast to the scrotum, which drains into the nearby superficial inguinal
nodes.

14. THE SCROTUM
• The scrotum is a fibromuscular cutaneous sac, located between the penis and
anus. The scrotum contains three major (paired) structures:
• Testis – the site of sperm production.
• Epididymis – situated at the head of each testicle. It functions as a storage
reservoir for sperm.
• Spermatic cord – a collection of muscle fibres, vessels, nerves and ducts that
run to and from the testes.

15. • There are also muscle fibres located within the scrotum. The dartos muscle is a
sheet of smooth muscle, situated immediately underneath the skin. It acts to help
regulate the temperature of the scrotum, by wrinkling the skin – this decreases
surface area, reducing heat loss.

17. Vessels
• The scrotum receives arterial supply from the anterior and posterior scrotal
arteries.
• The scrotal veins follow the major arteries, draining into the external pudendal
veins.

18. Nerves
• Cutaneous innervation to the scrotum is supplied via several nerves, according to
the topography:
• Anterior and anterolateral aspect – Anterior scrotal nerves derived from the
genital branch of genitofemoral nerve and ilioinguinal nerve
• Posterior aspect – Posterior scrotal nerves derived from the perineal branches of
the pudendal nerve and posterior femoral cutaneous nerve.

19. Lymphatics
• The lymphatic fluid from the scrotum drains to the nearby superficial inguinal
nodes.

20. CLINICAL RELEVANCE: HAEMATOMA OF THE
SCROTUM
A haematoma may develop in the scrotum as a result of scrotal surgery or trauma in
the genital region
This results in swelling (oedema) and discolouration of the scrotal skin.

21. THE PROSTATE GLAND
• The prostate is the largest accessory gland in the male reproductive system.
• It secretes proteolytic enzymes into the semen, which act to break down clotting
factors in the ejaculate. This allows the semen to remain in a fluid state, moving
throughout the female reproductive tract for potential fertilisation.

22. • The prostate is positioned inferiorly to the neck of the bladder and superiorly to
the external urethral sphincter.
• The proteolytic enzymes leave the prostate via the prostatic ducts. These open
into the prostatic portion of the urethra, through 10-12 openings at each side of
the seminal colliculus (or verumontanum); secreting the enzymes into the semen
immediately before ejaculation.

23. • The prostate is commonly described as being the size of a walnut.
• Roughly two-thirds of the prostate is glandular in structure and the remaining
third is fibromuscular. The gland itself is surrounded by a thin fibrous capsule of
the prostate.

25. Vasculature
• The arterial supply to the prostate comes from the prostatic arteries, which are
mainly derived from the internal iliac arteries.
• Venous drainage of the prostate is via the prostatic venous plexus, draining into
the internal iliac veins.

26. Innervation
• The prostate receives sympathetic, parasympathetic and sensory innervation from
the inferior hypogastric plexus.

27. CLINICAL RELEVANCE
• Prostatic carcinoma represents the most commonly diagnosed cancer in men.
• Prostate cancer has the potential to invade nearby structures