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)

Aortic regurgitation by cardiac catheterization, Q. Aortic regurgitation by...

Q. Aortic regurgitation by Cardiac Catheterization? Often cardiac catheterization is not indicated as reliable information for management decision making can be obtained throug

Define feeding for infants of hiv/aids mothers, Define Feeding for Infants ...

Define Feeding for Infants of HIV/AIDS Mothers? It is recommended to continue breast-feeding even if the disease will continue to be transmitted. If these infants are not breas

Respiration, abnormal lung volumes and capacities

abnormal lung volumes and capacities

#Cystic Fibrosis in Population , The cystic fibrosis allele occurs in Europ...

The cystic fibrosis allele occurs in European populations with q=0.02, what fraction of this population can be expected to have cystic fibrosis?

Explain about the cardiovascular disease and stroke, Explain the Cardiovasc...

Explain the Cardiovascular disease and stroke? Obesity may be an independent risk factor for coronary heart disease (CHD) with the degree of obesity being directly proportional

What is cerebrum, What is Cerebrum Cerebrum is divided into right and l...

What is Cerebrum Cerebrum is divided into right and left parts known as cerebral hemisphere. It is the largest part of the brain. The functions of the cerebrum:  It recei

Explain difficult feeding and poor growth, Explain Difficult Feeding and Po...

Explain Difficult Feeding and Poor Growth to recognition of congenital heart disease? Difficult Feeding and Poor Growth: The parent of an infant with CHD may complain that the

What is the cell theory, Cell theory is a theory that asserts that the cell...

Cell theory is a theory that asserts that the cell is the ingredient unit of the living beings. Before the discovery of the cell, it was not examined that the living beings were

Explain adverse effects of interferon alfa, Adverse Effects Of interferon a...

Adverse Effects Of interferon alfa Intramuscular or subcutaneous injection of interferon is commonly associated with an influenza-like syndrome, especially during the first wee

What would its new ph be if the concentration of h3o ion, If a solution has...

If a solution has a pH of 7.5, what would its new pH be if the concentration of H 3 O ions in the solution were increased by 100 times? Explain your reasoning. As a tenfold inc

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