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 precautions for estimation of vitamin c in chillies, Define Precauti...

Define Precautions for Estimation of Vitamin c in Chillies? 1. Rinse all glassware with 3% metaphosphoric acid before you begin your practical and subsequently each time you wa

Test of deep vein thrombophlebitis, Test of Deep vein Thrombophlebitis ...

Test of Deep vein Thrombophlebitis Place blood pressure cuff on unaffected calf and inflate until pain is elicited (usually greater than 150 mm Hg).  Place blood press

Explain dehydration, Explain Dehydration Dehydration is one of the anc...

Explain Dehydration Dehydration is one of the ancient food processing techniques.  Dehydration means to completely remove water under controlled  conditions, in such a way

Role of enzymes in metabolism, ROLE OF ENZYMES IN METABOLISM Enzymes re...

ROLE OF ENZYMES IN METABOLISM Enzymes require a non-protein  part  for  their optimal activity, which may be  a coenzyme or a metal ion. This has also been  stated earlier that

What is av block, Q. What is AV Block ? First Degree AV Block At ...

Q. What is AV Block ? First Degree AV Block At rest commonly disappears with exercise owing to the vagal withdrawal. The development of a prolonged PQ segment after exerc

Brain neurosecretory cells and their hormones, Brain Neurosecretory Cells a...

Brain Neurosecretory Cells and their Hormones Kopec was the very first to suggest the role of hormones in controlling metamorphosis. On the base of his experiments on the lar

Animal phylum that contains creatures with analogous organs, Q. Most insect...

Q. Most insects have wings. Which is the other animal phylum that contains creatures with analogous organs? Besides the phylum Arthropoda another animal phylum with flying crea

Why iodine is important for human body, Why Iodine is Important for Human B...

Why Iodine is Important for Human Body? Iodine is an essential constituent of the thyroid hormones: thyroxine (T 4 ) and triiodothyronine (T 3 ), which have a key role in growt

Growth and development of plants, Growth and Development of Plants You...

Growth and Development of Plants You must have seen beautiful plants growing in pots in a garden. The plant grows while the pot does not. As a rule living things grow, but non

Characteristics of the five-kingdom classification, Characteristics of the ...

Characteristics of the Five-Kingdom classification At present, as you know, the trend is to follow the five-kingdom classification. However, while accepting the Five-Kingdom C

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