Testes (testicles), Biology

Assignment Help:

TESTES (TESTICLES) -

  1. 2 in number (Diarchic). Pinkish in colour. Oval shaped.
  2. 4-5 cms long, 2.5 cm wide and 3 cm thick. Mesodermal.
  3. In embryonic stage attached to kidney by mesorchium membrane.
  4. In embryo at 7th month of division descend down in scrotel sac. Condition is extra abdominal, due to it 3°C less temperature is available, helpful in spermatogenesis.
  5. Both scrotel sac internally separated by septum scroti. External by a scar-like raphe.
  6. In scrotel sac fat layer is absent, involuntary muscles are dertos tunic present.
  7. Lumen of scrotel sac is vaginal coelome, in it testes present.
  8. Vaginal coelome is connected to main coelome by inguinal canal.
  9. In some cases testes do not descend down in sac, condition is cryptorchidism such animals are high flankers (sperm are not produced)
  10. Testes is attached to pre position by spermatic cord (gonadial artery, gonadial vein, nerve and connective tissue present).
  11. Testis is attached to wall of scrotel sac by elastic structure i.e. gubernaculum cordis.
  12. Unit of testis is seminiferous tubule where sperms are manufactured by spermatogenesis. All tubules form a cord of 200-400 meter. These tubules are spreaded in connective tissue.
  13. In tissue interstitial cells or cells of Leyding present. These cells secrete testastaron or androgen hormones to control secondary sexual characters.
  14. Outside each seminiferous tubule, tunica propria present. Inside it germinal epithelium or basement membrane present. Made up of cuboidal epithelium.
  15. Epithelium consists of P.G.C. and few sertoli cells.
  16. P.G.C. (Primordial germ cells) are endodermal in nature.
  17. P.G.C. are responsible for spermatogenesis.
  18. Different stages of formation of sperms can be seen as spermatogonia, primary spermatocyte, sec. spermatocyte, spermatid and sperms.
  19. Sertoli cells or nurse cells or sustentacular cells are nourishing cells i.e. provide glycogen as food to develope sperms. So sperm's head is embeded in sertoli cells.
  20. Around testes, testicular capsule present made up of 2 layers.
  21. Outer is tunica vaginalis & inner is tunica albuginea.
  22. From tunica albuginea straight vertical spetum mediastinum is originated from it septula testes are given out to form 200-300 compartments.
  23. In each compartment seminiferous tubule present.
  24. On tunica albuginea, mediastinum & septule testes, a membrane present rich in blood supply. This membrane is tunica vescularosa.
  25. Surgical removal of testes is orchidectomy & gonad is castration or gelding.

2406_testis.png 1933_testis1.png


Related Discussions:- Testes (testicles)

How plants control opening and closing of the stomata, How plants control t...

How plants control the opening and the closing of the stomata? The closing and the opening of the stomata depend upon the necessity of the plant to lose water and heat through

Rationale based on theories of miasma or contagion, Early campaigns of the ...

Early campaigns of the 19th century that focused on sanitation, hygiene, housing, and nutrition had little effect in controlling communicable disease due to flawed rationale based

Which areas of the globe is gymnosperm abundance noteworthy, Q. In which ar...

Q. In which areas of the globe is gymnosperm abundance noteworthy? These plants are the typical vegetation of cold regions like the boreal forest or taiga of the northern hemis

Define the history of food microbiology, Normal 0 false false...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Reproduction, name the sturcture formed when the male and female nuclei fus...

name the sturcture formed when the male and female nuclei fuse during fertilisation.

Brain region responsible for the equilibrium of the body, Q. Which is the b...

Q. Which is the brain region responsible for the coordination and equilibrium of the body? In the central nervous system the cerebellum is the main controller of the motor equi

Explain about the physiological accommodation, Explain about the Physiologi...

Explain about the Physiological Accommodation Physiological Accommodation contractile power of the ciliary muscle required to change the focussing power of the eye by ID. Meas

What could have caused the discrepancy, If the class's value did not match ...

If the class's value did not match the expected value of water, let's assume everyone was actually correctly using the devices and there was no "user error." What could have caused

Presence and constancy - synthetic characters, Presence and Constancy - Syn...

Presence and Constancy - Synthetic Characters Presence and constancy refer to how uniformly a species occurs in different stands in a community. For example, when a species is

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd