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)

What do you mean by bleeding index, Q. What do you mean by Bleeding Index? ...

Q. What do you mean by Bleeding Index? This factor is applicable at this stage to evaluate the health of one stage implants in which the transmucosal component allows the forma

Explain some guidelines to help in use drugs wisely, Explain some Guideline...

Explain some Guidelines to Help in Use Drugs Wisely? By now, you are aware that the interaction of foods and drugs is a complex problem. Researchers cannot always predict wheth

Determine the molecular function, Please answer the following three questio...

Please answer the following three questions on Sequence Z: Metadata The GO Ontology is a very widely-used resource in the bioinformatics community as a tool to annotate

Differences between vertebrates and the other chordates, What are the diffe...

What are the differences between vertebrates and the other chordates? Vertebrates are dissimilar because they have a spinal column (vertebral column). In these animals the noto

Ozone layer and its depletion, About 90% of ozone of atmosphere resides in ...

About 90% of ozone of atmosphere resides in stratosphere (16 to 40 km) layer of atmosphere as ozone layer. It protects life on this planet from harmful U.V. radiations. In absence

Phylum annelida, what so special for phylum annelida

what so special for phylum annelida

Define traditional cycle of root canal treatment, Define Traditional Cycle ...

Define Traditional Cycle of Root Canal Treatment The traditional cycle of Root Canal Treatment a) Dig in the tooth to make a big hole b) Then, look through this hole to f

Ecological pyramids - ecosystem, Ecological Pyramids - Ecosystem The a...

Ecological Pyramids - Ecosystem The ancient Egyptians constructed elaborate tombs called pyramids. The base of the pyramid is broad and it supports the upper levels of the str

Physical weathering-weathering of rocks, Physical Weathering Mechanical...

Physical Weathering Mechanical forces acting upon the rocks cause physical weathering. Temperature fluctuations cause expansion and contraction of rock surface resulting in the

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