Figure 16­12
Downloaded
by
[Rutgers
University
130.219.8.11]
at
[04/08/15].
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McGraw-Hill
Global
Education
In this micrograph, the nucleus of one of the Sertoli cells is identified by the arrow and a portion of its cytoplasm is
Holdings,
also discernible. Sertoli cells rest on the basement membrane of the seminiferous tubule and extend to the lumen. At
their basal, or basolateral, surfaces, tight (occluding) junctions between adjacent Sertoli cells constitute the blood-
testis barrier, which prevents the migration of toxins and keeps other antigens and blood-borne proteins from en-
LLC.
tering the seminiferous compartment.
Not
to
The Sertoli cell cytoplasm is highly irregular in shape and encloses the gametogenic cells as they proceed through
be
the mitotic and meiotic divisions. Sertoli cells thus provide a physical support to the gametogenic cells and mediate
redistributed
movements of hormones and metabolites to the gametogenic cells. The Sertoli cells establish two compartments in
the seminiferous tubule: a basal compartment of spermatogonia and preleptotene spermatocytes and an adluminal
compartment containing primary spermatocytes, secondary spermatocytes, and spermatids. Within these two mi-
or
croenvironments, Sertoli cells control the movements of the cells throughout the seminiferous tubule.
modified
Sertoli cells remove degenerating spermatogenic cells and the residual cytoplasm of the spermatids as they
are transformed into spermatozoa. In addition, Sertoli cells secrete androgen-binding hormone that concentrates
in
any
testosterone, which is secreted by the interstitial cells within the seminiferous tubules. Sertoli cells also produce es-
way
trogen and inhibin, which have inhibitory effects on the spermatogenic process.
without
Elongated nuclei of myoid cells (arrowhead) are located in the basal region of the seminiferous tubules.
permission.
919

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