Seminiferous tubule (sectional view)शुक्रजनक नलिका (काट)

NCERT Fig 2.2, 2.5 · Class 12 Biology · Chapter 2 · interactive diagram

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Parts and their functions

Spermatogonia (शुक्राणुजन) — Male germ cells (2n = 46) on the inner wall of the tubule; multiply by mitosis. Some become primary spermatocytes.
Primary spermatocyte (2n) (प्राथमिक शुक्राणुकोशिका) — Undergoes meiosis I (reduction division) → two secondary spermatocytes.
Secondary spermatocyte (n) (द्वितीयक शुक्राणुकोशिका) — Haploid, 23 chromosomes; meiosis II → spermatids.
Spermatids (n) (शुक्राणुप्रसू) — Four haploid spermatids per primary spermatocyte; change into sperms by spermiogenesis.
Sperms (spermatozoa) (शुक्राणु) — Heads embedded in Sertoli cells, then released into the lumen — spermiation.
Sertoli cells (सर्टोली कोशिकाएँ) — Provide nutrition to the germ cells; FSH acts on them (factors that help spermiogenesis).
Leydig (interstitial) cells (लीडिग कोशिकाएँ) — In the interstitial spaces OUTSIDE the tubules; make androgens (testicular hormones). LH acts on them.
Interstitial space (अंतराकाशी स्थान) — Region between tubules: small blood vessels, Leydig cells and immunologically competent cells.
Blood vessel (रक्त वाहिका) — Small blood vessels lie in the interstitial space.
Tubule wall (नलिका भित्ति) — Each testicular lobule has 1–3 highly coiled seminiferous tubules (about 250 lobules per testis).
Lumen (गुहा) — Central cavity into which sperms are released.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 2.2, 2.5. Report a mistake