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)

Explain about the tray and tunnel dryers, Explain about the Tray and Tunnel...

Explain about the Tray and Tunnel Dryers? Tray and tunnel dryers are widely used in the food industry. In both cases the material being dried is supported on multiple trays, wi

What is the disease caused by vitamin d deficiency, What is the disease cau...

What is the disease caused by vitamin D deficiency? Which tissue does it affect? The lack of vitamin D causes the disease called as rickets (rachitis), characterized by decalci

How you would accomplish cloning using of numbered steps, A restriction map...

A restriction map of plasmid and a human gene of identified sequence is demonstrated below. Your job is to clone the human liver cDNA for that gene than the start codon is closer t

Some common air pollutants: carbon monoxide, 1.   Carbon monoxide (CO): ...

1.   Carbon monoxide (CO): It is colourless, odourless, tasteless gas and is not soluble in water. Source: CO is produced due to: (i)     Incomplete combustion of fuels

What is the Evolution of migration, Evolution of migration Eg Be...

Evolution of migration Eg Benefits associated with migratory flights must be greater than those associated with staying in Alaska and having to tolerate seasonal changes

Parthenogenesis, what are the consequences of parthenogenesis in human life...

what are the consequences of parthenogenesis in human life if humans reproduced through parthenogenesis?

What are enzymes, What are enzymes? What is the importance of enzymes for l...

What are enzymes? What is the importance of enzymes for living beings? Enzymes are proteins that are catalysts of chemical reactions. From Chemistry it is called that catalysts

Explain canal obstruction - non-surgical endodontic, Explain Canal Obstruct...

Explain Canal Obstruction - Non-surgical Endodontic Retreatment     File work shorter than the normal apical and feel a great resistance to reach the true length a. A retain

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