Question

Sustentacular cells are found in
A. Testes of mammal
B. Ovary of mammal
C. Testes of Ascaris
D. Pancreas of frog

Answer 1

Hint: Sustentacular cells provide nursing and nutrition to the sperm cells.

Complete answer:
Sustentacular cells are found in the Testes of mammals. They are also known as ‘Sertoli cells' or ‘Nurse cells'. They are pyramidal shaped structures present in the stratified epithelium of seminiferous tubules inside the testes of man. They are responsible for providing nutrition and structural support to the growing sperm as the head of the spermatozoa gets embedded into it during spermatogenesis.

Additional Information:
The functions of Sustentacular cells are as follows:

They help in the growth of germ cells.
They secrete the testicular fluid into the testicular cavity and also helps in phagocytosis of the dead, non-functional, and degenerative germ cells.
They form the ‘blood-testis barrier'. It is a kind of tight junction that is responsible for the prevention of leakage of certain molecules between the Sertoli cells. This helps in maintaining a proper chemical composition of the testicular fluid. It also prevents germ cells from autoimmune antibodies.
They produce certain enzymes like ‘androgen binding protein’ as well as hormones like inhibin and anti-Mullerian hormone.
They also produce an enzyme that converts testosterone to estrogen and DHT (Dihydrotestosterone).

Note:
- No new Sertoli cells are formed after puberty in human males.
- They are the site of the process of ‘spermiation’ (formation of mature sperm cells from spermatozoa).
- The olfactory epithelium also consists of some specialized structural cells that are called Sustentacular cells.
- Testosterone in males is secreted by the Leydig cells.