The Male Reproductive System II

Histology:2nd stage Dr. Raja Ali
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The Male Reproductive System II
Sertoli Cells (fig.1):
? The Sertoli cells, are highly important For the function of the testes.
? They are columnar or pyramidal cells that largely envelop cells of the spermatogenic lineage and function as supporting cells or nurse cells.
? The bases of the Serroli cells adhere to the basal lamina and their apical ends extended to the lumen of the sem. tubules.
? Smooth ER, some rough ER, well-developed Golgi complexes, as well as numerous mitochondria and lysosomes. Have elongated nucleus, which can be triangular in outline.
? As , flagellar tails of the spermatids develop, they appear as tufts extending from the apical ends of the Sertoli cells .
? Sertoli cells have several specific functions within the sem. tubules epithelium:
A-Support, protection , and nutrition of developing spermatogenic cells.
B-Exocrine and endocrine secretion:
• Sertoli cells continuously secrete into the seminiferous tubules a fluid used for sperm transport in the direction of the genital ducts.
• Secretion of nutrients and androgen-binding protein (ABP), which concentrates testosterone to a level required for spermiogenesis, is promoted by follicle-stimulating hormone (FSH).
• In an endocrine manner, Sertoli cells release the steroid estradiol derived from testosterone and secrete the inhibin , which in a feedback loop with the anterior pituitary gland suppresses synthesis and .
• In the fetus Sertoli secrete a müllerian-inhibiting substance (MIS) that causes regression of the embryonic miillerian (paramesonephric) ducts; without MIS these ducts persist and become parts of the female reproductive tract.
C-Phagocytosis: During spermatogenesis excess cytoplasm shed as residual bodies is phagocytosed and digested by Sertoli cells lysosomes.