Anatomy of the Penis – Notes and MCQ for NEET, GPAT, CUET, Nursing exams
Anatomy of the Penis – Notes
1. Overview
The penis is the external male genital organ involved in urination and sexual reproduction.
2. Parts of the Penis
| Part | Description |
|---|---|
| Root (Base) | Attached portion; includes crura and bulb |
| Body (Shaft) | Free portion between root and glans |
| Glans Penis | Expanded distal end of the corpus spongiosum; includes external urethral orifice |
3. Erectile Tissues
| Structure | Description |
|---|---|
| Corpus Cavernosum (x2) | Paired dorsal columns; responsible for erection |
| Corpus Spongiosum | Surrounds the urethra; prevents urethral collapse during erection |
4. Tunics & Coverings
| Layer | Function |
|---|---|
| Skin | Loose and elastic, allows expansion |
| Dartos fascia | Smooth muscle involved in temperature regulation |
| Buck’s fascia | Deep fascia that surrounds erectile tissues |
| Tunica albuginea | Dense fibrous covering of corpora cavernosa and corpus spongiosum |
5. Blood Supply
-
Arteries: Branches of the internal pudendal artery
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Deep artery → corpora cavernosa
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Dorsal artery → glans and skin
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Bulbourethral artery → corpus spongiosum
-
-
Veins:
-
Superficial dorsal vein (drains skin)
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Deep dorsal vein (drains erectile tissue)
-
6. Nerve Supply
| Nerve Type | Function |
|---|---|
| Somatic – Pudendal nerve (S2–S4) | Sensation and voluntary control |
| Autonomic – Pelvic splanchnic nerves (parasymp.) | Erection (via nitric oxide) |
| Hypogastric plexus (symp.) | Ejaculation and detumescence |
7. Lymphatic Drainage
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Skin → Superficial inguinal lymph nodes
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Glans & Deep structures → Deep inguinal & external iliac lymph nodes
8. Urethra in Penis
-
Spongy (penile) urethra travels through the corpus spongiosum.
-
Opens at the external urethral orifice at the tip of the glans.
Quick Summary Table
| Structure | Location/Function |
|---|---|
| Corpus Cavernosum | Erection (main erectile bodies) |
| Corpus Spongiosum | Protects urethra, forms glans |
| Tunica Albuginea | Dense covering of erectile tissues |
| Dorsal Artery & Nerve | Run along dorsal shaft |
| Urethra | Passes through corpus spongiosum |
MCQs – Penis Anatomy
1. Which structure of the penis surrounds the urethra?
A. Corpus cavernosum
B. Corpus spongiosum
C. Tunica albuginea
D. Glans penis
Answer: B. Corpus spongiosum
2. The main artery responsible for erection is the:
A. Deep artery of the penis
B. Superficial dorsal artery
C. Femoral artery
D. External pudendal artery Answer: A. Deep artery of the penis
3. Sensory innervation to the penis is primarily via the:
A. Ilioinguinal nerve
B. Genitofemoral nerve
C. Pudendal nerve
D. Obturator nerve Answer: C. Pudendal nerve
4. Which fascial layer is deep and surrounds all erectile tissues?
A. Dartos fascia
B. Buck’s fascia
C. Scarpa’s fascia
D. Colles’ fascia Answer: B. Buck’s fascia
5. The penile urethra is located in the:
A. Corpus cavernosum
B. Tunica albuginea
C. Corpus spongiosum
D. Epididymis Answer: C. Corpus spongiosum