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 nutritional support management for radiation therapy, Explain Nutri...

Explain Nutritional Support Management for radiation therapy? For managing these patients on radiation therapy, the following measures can be under taken: 1. Administration

What is passive transport , The passive transport of molecules across a me...

The passive transport of molecules across a membrane does not require an input of metabolic energy. Rate of the diffusion or transport is proportional to the concentration gradient

What is the significance of proteins for living beings, Q. What is the sign...

Q. What is the significance of proteins for living beings? Proteins play an essential role in nearly all biological processes. Due to their variety they can suppose many divers

Explain the mitotic prophase, Which of the following best explains what wou...

Which of the following best explains what would happen if recombination (crossing-over) happens during mitotic prophase? A. Recombination during mitosis will lead to segregatio

Estimate daily energy requirement and safe protein intake, Estimate Daily e...

Estimate Daily energy requirement and safe protein intake? The estimated mean daily per capita energy requirement of 2070 Kcal rounded up  to 2100 Kcal is based on WHO technica

Assessment of magnesium status and dietary requirements, Define Assessment ...

Define Assessment of Magnesium Status and Dietary Requirements?  In order to estimate Mg requirements and establish relationship between magnesium intake and deficiency, it is

Define the concepts of lipids, Define the Concepts of Lipids? You have ...

Define the Concepts of Lipids? You have studied the classification of lipids in your theory lesson. Lipids, you learnt, are classified as simple, compound or derived lipids on

Termination of rna, Transcription   continues   until a termination   serie...

Transcription   continues   until a termination   series   is reached.   The most common termination signal is a GC-rich region which is a palindrome, followed by an AT-rich sequen

What is central shunt in palliative operations, What is Central Shunt in Pa...

What is Central Shunt in Palliative Operations? When the pulmonary artery branches are small, an interposition graft could be used as a shunt between main pulmonary artery and

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