external and internal structure of testes

External and Internal structure, location, vascular supply, the innervations and age – related

changes of the testes. Varicocele

Tural AbdullayevGroup 30

External structure of the testes


• The testes are suspended outside the body in the sac called Scrotum

• The left testis lies slightly lower than the right


• The testes is covered with multilayered tunica • It facilitates blood supply to the testes and

creates partition between sperm producing regions of the testes

• There are 3 layers to the tunica :1. Tunica vasculosa2. Tunica albuginea3. Tunica vaginalis


• Tunica vasculosa– Is the inner layer of the tunica – Covered by tunica albuginea– Consist of blood vessels and connective tissue– Facilitates blood supply to the testes


• Tunica albuginea– Dense layer of tissue which encases the testes– Connect to the layers of fibers which surround the

epididymis – It also extends into the testis, creating partitions

between seminiferous tubules


• Tunica vaginalis– Overlying tunica albuginea – The are 2 layers of tunica vaginalis:

1. Visceral – overlies the tunica albuginea2. Parietal – lines the scrotal cavity

Thin fluid layer separates the 2 sections and reduces friction between the testes and scrotum


• Tunica vaginalis is covered with internal spermatic fascia

• Internal spermatic fascia is covered with cremaster muscle which arises from the internal oblique muscle

• External spermatic fascia overlies cremaster muscle

Internal structure of the testes


Seminiferoustubule

Straight tubule

Rete testis

Efferent ductules Epindidymis

Ductus deferens


• Seminiferous tubule– Lie within the testes and are separated by

partitions, which are extensions of the tunica albuginea

– Partitions divide the testes into lobules which contain the seminiferous tubules


• Mediastinum – Region of tissue which connects to the rete testis– Supports the blood vessels and lymphatic system

of the testes


• Straight tubules– Connect seminiferous tubules to the rete testis


• Rete testis– Seminiferous tubules open into a series of

channels called the rete testis– Facilitate the transport of sperm from the testes

to the sperm transport ducts of the penis.


• Efferent ducts – Located between the rete testes and the

epididymis– They connect the testes to the male ducts and

facilitate the transport of sperm from the testes.


• Ductus deferens– Muscular duct that transport spermatozoa from

the tail of the epedidymis to the ejaculatory duct– Passing through the deep inguinal ring – Between the ureter and ejaculatory duct it

expands to form the ampulla


• Ejaculatory duct– Penetrates through the prostate gland to connect

with the prostatic urethra

Vascular supply ( arteries )

Vascular supply

• Arteries– Testicular arteries ( a. testicularis )• Originate from the abdominal aorta and descent into

the scrotum through the inguinal canal to supply the testes

– Cremasteric arteries ( a. cremaster )• Originate from the inferior epigastric branch of the

external iliac artery, accompany the spermatic cord into the scrotum

Vascular supply

• Veins– They accompany the arteries – The veins join the internal pudental veins that

connect with the internal iliac vein in the pelvis• Right testicular vein

– Joins the inferior vena cava• Left testicular vein

– Joins the left renal vein

Vascular supply • Veins

– veins emerge from the back of the testis, and receive tributaries from the epididymis

– They unite and form pampiniform plexus– Panpiniform plexus constitutes the greater mass of the spermatic

cord– Below the subcutaneous inguinal ring, they unite to form three or

four veins, which pass along the inguinal canal, and, entering the abdomen through the abdominal inguinal ring, coalesce to form two veins, lying one on either side of the internal spermatic artery.

– These unite to form a single vein, which opens, on the right side, into the inferior vena cava, on the left side into the left renal vein

Vascular supply

• Lymphatic drainage– Testes are the only ones that do not drain to the

inguinal lymph nodes– Lymphatics course along the route of the testicular

vessels to reach the para-aortic lymph nodes at the level of the L2 vertebra

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 and sensory fibres.

• The T10 spinal segment provides the sympathetic nerve fibers that innervate the testes. – They travel by way of the lesser splanchnic nerves and synapse at

the celiac ganglion.– Post-ganglionic fibers then follow the testicular artery along its course– Genital branch (L2) of the genitofemoral nerve (L1, L2) of the lumbar

plexus provides sensory innervation to the tunica vaginalis of the testes

Age – related changes• Fetal period

– Endocrine function is dominant ( production of androgene hormones )– Lumen of seminal ducts is absent

• After the birth till the 11 years– Testis enlargement is slow

• After the 11 – 12 years – Testis enlargement is fast– Permanent spermatogenesis is observed

• Adult men– No visible changes of the testes size

• Old man– More connective tissue– Testis decrease in size, it is more hard– Inside -> Ischemia– Widening of rete testis canalicles– Less seminal canalicles– Production of testosterone is decreased– Less spermatozoa in the ejaculate fluid– Decrease in ejaculate fluid amount

Varicocele• Is a collection of dilated veins that arise from pampiniform

plexus– Idiopathic varicocele

• occurs when the valves within the veins along the spermatic cord do not work properly

• This results in backflow of blood into the pampiniform plexus and causes increased pressures

• A majority of idiopathic varicoceles occur on the left side because the left testicular vein travels superiorly and connects to the left renal vein

– Secondary varicocele• due to compression of the venous drainage of the testicle• Cause of a secondary varicocele is the so-called "Nutcracker syndrome“

– a condition in which the superior mesenteric artery compresses the left renal vein, causing increased pressures there to be transmitted retrograde into the left pampiniform plexus

external and internal structure of testes

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