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)

Man-made disasters- chemical disasters, Chemical disasters arise from harm...

Chemical disasters arise from harmful and potentially hazardous chemicals, which if released of misused can pose a threat to the environmental. Its range depends upon military and

Name the hormones produced by the testes, Name the hormones produced by ...

Name the hormones produced by (a) the testes, (b) the ovaries.   (a) The testes produce testosterone. (b) The ovaries produce oestrogen and progesterone.

What is the major biological function of ribosomes, Q Where in the cell can...

Q Where in the cell can ribosomes be found? What is the major biological function of ribosomes? Ribosomes can be found free in the cytoplasm, adhered to the external side of th

Heart in fishes, Fishe s - Heart is 2 chambered 1 auricle & 1 ventr...

Fishe s - Heart is 2 chambered 1 auricle & 1 ventricle present. Sinus venosus, truncus or conus arteriusus present. Only impure blood come in heart so heart is venous he

What is the difference between a hormone and a morphogen, What is the diffe...

What is the difference between a hormone and a morphogen? How do they act and what type of development do they control?

Cardinal manifestation of cardiovascular disorders, CARDINAL MANIFESTATION ...

CARDINAL MANIFESTATION OF CARDIOVASCULAR DISORDERS Cardiovascular symptoms that most often trouble patients are: 1. Chest Pain 2. Shortness of Breath 3. Palpitation

Subphylum opalinata, Subphylum Opalinata Body covered with longitudin...

Subphylum Opalinata Body covered with longitudinal rows of cilium like ,organelles but true ciliature absent. Parasitic; cytosome lacking; two to many nuclei of one type.

Explain food applications of pullulan, Explain Food Applications of pullula...

Explain Food Applications of pullulan The food applications of pullulan include:  Due to its oxygen barrier properties, it can be used as a packaging material for fat /

Class of crustacea - branchiopoda, Class of Crustacea - Branchiopoda ...

Class of Crustacea - Branchiopoda These are small fresh water crustaceans. The trunk appendages are flattened and leaf like and are helpful for locomotion also respiration he

National approach to deal with the prevention of obesity, Define National A...

Define National Approach to deal with the Prevention of Obesity? A number of countries have adopted a national approach to deal with the prevention of obesity and other non-com

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