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 changes in feeding behaviour of infants, Explain Changes in feeding...

Explain Changes in feeding behaviour of infants? On maturation of neuro-muscular system, the body is able to coordinate sucking, swallowing and breathing. Till about three mont

Importance of the glucose blood level for human health, Q. What is the impo...

Q. What is the importance of the glucose blood level for human health? The glucose blood level (glycemia) must be kept normal if it is abnormally low there is not sufficient gl

Define reaction of fehling solution with lactose, Define Reaction of Fehlin...

Define Reaction of Fehling solution with lactose? After complete reduction of cupric ions, the indicator is reduced by lactose to a leuco compound, restoring the red colour of

Six kingdom worksheet, what protist changes shape constantly and flows arou...

what protist changes shape constantly and flows around its food to engulf it?

Define the sources of vitamin d, Define the Sources of Vitamin D? Vitam...

Define the Sources of Vitamin D? Vitamin D, also called the sunshine vitamin is easily manufactured in the skin from 7-dehydro cholesterol on exposure to sunlight, as already m

What is the kind of circulatory system present in annelids, Q. What is the ...

Q. What is the kind of circulatory system present in annelids? In beings of the phylum Annelida the circulatory system is closed that is blood circulation takes place only with

Explain kidney transplant, Consider the following four statements (a - d) r...

Consider the following four statements (a - d) regarding kidney transplant and select the two correct ones out of these. 1. Even if a kidney transplant is proper the recipient m

Regulation of glycogen metabolism, Regulation of Glycogen Metabolism It...

Regulation of Glycogen Metabolism It  is  important  for  you  to  understand  that  glycogenesis and gluconeogenesis are regulated  reciprocally. There  is  a  hormonal  regul

What is signifying by concentration gradient, Q What is signifying by conce...

Q What is signifying by concentration gradient? Is it correct or not to refer to "concentration gradient of water"? Concentration gradient is the variation of concentration of

Define the role of protein and purines, Q. Define the Role of Protein and P...

Q. Define the Role of Protein and Purines? Cellular materials of plants, grams and legumes and animal glandular organ meats (liver, pancreas brain, kidneys) contain nucleoprote

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