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)

Agro industrial-complete feed blocks, Complete feed blocks For manufac...

Complete feed blocks For manufacturing the pellets, processes such as grinding, mixing, steaming and pressing and some times extruding, are applied using special and expensive

Explain hypertensive disorders of pregnancy, Explain Hypertensive Disorders...

Explain Hypertensive Disorders of Pregnancy? Hypertension may have been existing before pregnancy. Alternatively, a mother may develop hypertension during pregnancy, a pregnanc

Show imbalances of basal nuclei, Q. Show Imbalances of basal nuclei? BA...

Q. Show Imbalances of basal nuclei? BASAL NUCLEI - Gray matter "islands" located deep within cerebral white matter. These nuclei process a variety of descending motor informat

Define the translocation of food through sieve tubes, Arrange the following...

Arrange the following processes sequentially to define the translocation of food through sieve tubes.   i. Unloading of sugar in sink cells (or cells of root).  ii. Uptak

Respiration, difference between anaerobic respiration and fermentation

difference between anaerobic respiration and fermentation

Explain the term antioxidants, Normal 0 false false false ...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

State fluid exchange between blood plasma in a capillary, Which of the foll...

Which of the following statements are true for fluid exchange between the blood plasma in a capillary in the leg and the interstitial spaces surrounding that capillary? A. Bloo

Trinomial system, who proposed trinomial system of classification? in ALLEN...

who proposed trinomial system of classification? in ALLEN modules ans is Huxley & Stricklandt but in AAKASH its given Lamarck so what is correct?

Explain clear liquid diet, Explain Clear Liquid Diet Clear Liquid Die...

Explain Clear Liquid Diet Clear Liquid Diet:  It is composed  of  foods with  low residue content which  help  to minimize  the  load of food needing digestion  in  the  int

Amphibians, Ask questionImagine you are studying a group of amphibian speci...

Ask questionImagine you are studying a group of amphibian species that vary in their habitats, some living in dense murky water, and others living in very clear ponds. What kind of

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