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)

Treatment of diabetic ketoacidosis, Q. Treatment of diabetic ketoacidosis? ...

Q. Treatment of diabetic ketoacidosis? The components of treatment of NKHDC are: 1) control of water loss. 2) control of sugar using insulin. 3) adjust electrolytes li

What effect does alcohol have on reaction time, (a) What effect does alcoho...

(a) What effect does alcohol have on reaction time? (b) What other short-term effects does alcohol have?  (c) What long-term effects can result from an exce

What are the indications of cardiac transplantation, What are the indicatio...

What are the indications of Cardiac Transplantation ? Indication :  Patients in NYHA class IV with heart failure, refractory to medical management caused by end stage corona

Mitochondria, MITOCHONDRIA  (Singular-  MITOCHONDRION) These are cons...

MITOCHONDRIA  (Singular-  MITOCHONDRION) These are conspicuous, hollow  sac liked  cell organelles found in all eukaryotic  cells except  mature  red  blood  corpuscles RBC s

Bio-insecticides and bio-pesticides, A large number of plants are used for ...

A large number of plants are used for bio-pesticides and bio-fertilizers. Several plant species are used as insecticides against aphids and larvae of insect pests: for insects like

Define methods used in combination with pasteurization, Define methods used...

Define methods used in combination with pasteurization? Typical other methods used in combination with pasteurization include: 1.  Refrigeration as in the case of   milk

Purposes of assessing growth and development in children, PURPOSES OF ASSES...

PURPOSES OF ASSESSING GROWTH AND DEVELOPMENT IN CHILDREN Before you assess the growth and development you should be aware of the purpose of monitoring. The purposes are a

How do populations of predators vary in predatism, How do populations of pr...

How do populations of predators and prey vary in predatism? Whenever a predator population enhances at the first moment the prey population tends to decrease. At a second momen

Explain the food applications of carrageenan, Food Applications of Carragee...

Food Applications of Carrageenan Carrageenan consists of a family of hydrocolloids, which have different properties and it has a wide variety of uses. Some examples of properti

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