Spermatogenesis
i.e. (Occurs in seminiferous tubules): (11-12-IBS-Embryology 8th)Spermatozoa are formed in the walls of the seminiferous tubules of the testesSPERMATOGENESIS - formation of gametes (spermatozoa) takes only during the reproductive periods which begins at the age of puberty (12 to 16 years) and continue even though old age* The process of spermatogenesis, including spermiogenesis requires about two months** for its completion.Difference between Spermatogenesis and SpermiogenesisSpermatogenesis is the complete process of formation of a spermatozoon from a spermatogonium. It includes first and second meiotic division and spermiogenesisSpermiogenesis - is the process of transformation of a rounded spermatid into a spermatozoanSERTOLI CELLSSertoli cells are specialized cells within the seminiferous tubules and are involved in the orchestration and coordination of all of the key events in spermatogenesis (including spermiogenesis)Function of Sertoli cells1. Provide support, nutrition to developing spermatozoa2. Protect developing germ cells by forming the blood testes barrier (BTB)3. Secretion of important substances - Androgen binding protein (ABP)*, Inhibin*, Mullerian Inhibiting substance (MIS)*, contain aromatase (CYP)*4. Presence of FSH receptors5. Important role in the final maturation phase of spermiogenesis which is characterized by shedding of excess or residual cytoplasm of the spermatids (Phagocytosis)
Starts at birth
Maximum in 37degC
Occurs in seminiferous tubules
Time required for a spermatogonium to develop into mature spermatozoan is 6 weeks
Embryology