Notes on Testes Structure and Function and MCQ on Male Reproductive system for NEET, GPAT, CUET, DMLT, Medical, Nursing and Pharmacy Exams
1. Overview
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The testes (testicles) are the male gonads, responsible for producing sperm (spermatogenesis) and testosterone (primary male sex hormone).
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Located in the scrotum, which maintains temperature ~2–3°C below body temp for optimal sperm development.
2. External Anatomy
| Structure | Description |
|---|---|
| Tunica vaginalis | Outer serous membrane derived from peritoneum |
| Tunica albuginea | Tough fibrous capsule that encloses and divides testis into lobules |
| Scrotum | Pouch of skin and smooth muscle that houses the testes |
3. Internal Structure
Each testis contains:
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~250–300 lobules, each with:
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Seminiferous tubules – where spermatogenesis occurs
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Interstitial (Leydig) cells – secrete testosterone
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Sertoli cells – support and nourish developing sperm
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Seminiferous Tubules
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Lined by germinal epithelium
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Contains:
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Spermatogonia → develop into mature sperm
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Sertoli cells → form the blood-testis barrier, provide nutrients, and secrete inhibin
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Leydig Cells
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Located in interstitial spaces
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Stimulated by LH (luteinizing hormone)
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Secrete testosterone
4. Sperm Transport Pathway
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Seminiferous tubules
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→ Straight tubules (tubuli recti)
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→ Rete testis
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→ Efferent ductules
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→ Epididymis (sperm maturation and storage)
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→ Vas deferens
5. Hormonal Control
| Hormone | Source | Action |
|---|---|---|
| FSH | Anterior pituitary | Stimulates Sertoli cells, spermatogenesis |
| LH | Anterior pituitary | Stimulates Leydig cells → testosterone |
| Testosterone | Leydig cells | Male secondary sex traits, spermatogenesis |
| Inhibin | Sertoli cells | Inhibits FSH release |
Key Points
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Sertoli cells = support spermatogenesis, blood-testis barrier
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Leydig cells = testosterone production
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Tunica albuginea = divides testes into lobules
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Spermatogenesis occurs in seminiferous tubules
MCQs on Testes Structure
1. Which of the following structures directly produces sperm?
A. Leydig cells
B. Rete testis
C. Sertoli cells
D. Seminiferous tubules
Answer: D. Seminiferous tubules
2. Which hormone stimulates the Leydig cells to produce testosterone?
A. FSH
B. LH
C. Inhibin
D. GnRH
Answer: B. LH
3. Which cells form the blood-testis barrier and support spermatogenesis?
A. Leydig cells
B. Spermatogonia
C. Sertoli cells
D. Myoid cells
Answer: C. Sertoli cells
4. The fibrous capsule surrounding the testes is called:
A. Tunica vaginalis
B. Tunica mucosa
C. Tunica albuginea
D. Tunica media
Answer: C. Tunica albuginea
5. What is the correct order of sperm flow out of the testis?
A. Rete testis → Seminiferous tubules → Efferent ductules
B. Seminiferous tubules → Rete testis → Efferent ductules
C. Epididymis → Rete testis → Seminiferous tubules
D. Efferent ductules → Seminiferous tubules → Rete testis
Answer: B. Seminiferous tubules → Rete testis → Efferent ductules
6. Testosterone is secreted by:
A. Epididymis
B. Sertoli cells
C. Leydig cells
D. Spermatogonia
Answer: C. Leydig cells