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)

Define the clinical manifestations of underweight, Define the Clinical Mani...

Define the Clinical Manifestations of Underweight? Underweight may predispose to fatigue, lethargy and breathlessness. Iron-deficiency anaemia is usually seen because the diet

Explain about the asepsis - methods of food processing, Explain about the A...

Explain about the Asepsis - Methods of Food Processing? Food is a living system and it has natural protection mechanisms in its raw agricultural state. Just removed once from t

Endosperm with micropylar and chalazal haustoria, Endosperm with Micropylar...

Endosperm with Micropylar and Chalazal Haustoria Some plants develop haustoria from both micropylar and chalazal ends of endosperm. In Nemophila aggressive haustoria arise fr

Clathrin-coated pits and vesicles, Clathrin-coated pits and vesicles are in...

Clathrin-coated pits and vesicles are included in both the endocytosis   of material   at the plasma membrane and the exocytosis of proteins from the Golgi   apparatus.  Electron

Endoplasmic reticulum (er), Endoplasmic reticulum (ER) is the network of m...

Endoplasmic reticulum (ER) is the network of membranous tubules in the cytoplasm of a cell; involved in production of the phospholipids, proteins, and the other functions. Rough E

Zoology, Write about 25 parasites of protozoans? And writ the class family ...

Write about 25 parasites of protozoans? And writ the class family and full history about these parasites?

Explain the procedure of taking blood pressure, Explain the Procedure of Ta...

Explain the Procedure of Taking Blood Pressure - Explain the procedure to the patient. In case patient is coming for first time to check the blood pressure explain to the patie

What do you know about tricuspid stenosis, Q. What do you know about Tricus...

Q. What do you know about Tricuspid stenosis? It is rare disease, with rheumatic etiology seen in 90 per cent of cases. In patients with rheumatic mitral stenosis only 3-5 per

Explain about probiotics and prebzotics, Explain about Probiotics and Prebz...

Explain about Probiotics and Prebzotics? We all have read or heard about probiotics and prebiotics at some point of time. However, what exactly do we mean by these terms? When

Can you explain toxic alkaloids, Q. Can you explain Toxic alkaloids? Al...

Q. Can you explain Toxic alkaloids? Alkaloids are the nitrogen heterocycles which occur mainly m plants as their salts of common carboxylic aciak such as citric, lac

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