External and internal structure of testes

External structure of the testes
Internal structure of the testes
Location of the testes
Vascular supply to the testes
Innervations of the testes
Age – related changes of the testes
Varicocele

1. External and Internal structure, location, vascular supply, the innervations and age – related changes of the testes. Varicocele Tural Abdullayev Group 30

2. External structure of the testes

3. 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

4. External structure of the testes 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 : Tunica vasculosa Tunica albuginea Tunica vaginalis

5. External structure of the testes Tunica vasculosa Is the inner layer of the tunica Covered by tunica albuginea C onsist of blood vessels and connective tissue Facilitates blood supply to the testes

6. External structure of 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

7. External structure of the testes Tunica vaginalis Overlying tunica albuginea The are 2 layers of tunica vaginalis : Visceral – o verlies the tunica albuginea Parietal – lines the scrotal cavity Thin fluid layer separates the 2 sections and reduces friction between the testes and scrotum

8. External structure of the testes 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

9. Internal structure of the testes

10. Internal structure of the testes

11. Internal structure of the testes 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

12. Internal structure of the testes Mediastinum Region of tissue which connects to the  rete testis Supports the blood vessels and lymphatic system of the testes

13. Internal structure of the testes Straight tubules Connect seminiferous tubules to the rete testis

14. Internal structure of the testes 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.

15. Internal structure of the testes 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.

16. Internal structure of 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

17. Internal structure of the testes Ejaculatory duct Penetrates through the prostate gland to connect with the prostatic urethra

18. Vascular supply ( arteries )

19. 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

20. 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

21. 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

22. 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

23. 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

24. Age – related changes Fetal period E ndocrine 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

25. 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 C ause 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