[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Anatomy](https://durgical.com/en/anatomy/) › [Pelvis · Male](https://durgical.com/en/anatomy/region/pelvis/) › Corpus spongiosum [Reproductive system](https://durgical.com/en/anatomy/system/reproductive-system/) · [Pelvis · Male](https://durgical.com/en/anatomy/region/pelvis/) # Corpus spongiosum The corpus spongiosum is the spongy column along the underside of the penis that surrounds the urethra; it stays softer in erection so semen can pass. Official name: Corpus spongiosum of penis [See in 3D →](https://durgical.app/?from=durgipedia&lang=en#region=pelvis&variant=male&select=corpus_spongiosum&side=r) Opens in the Durgical app, no sign-up needed. ## What it is A single cylinder of softer erectile tissue on the underside of the penis, around the spongy urethra. Its back end is the bulb; its front end widens into the glans. ## What it does Stays softer in erection so the urethra stays open for semen to pass. ## Key points - The bulb, its back end, lies on the perineal membrane behind the [scrotum](https://durgical.com/en/anatomy/scrotum/): the part crushed against the pubic arch in straddle injuries - Scarring of the spongy tissue around a urethral stricture (spongiofibrosis) sets how deep and long the stricture is and whether urethroplasty is needed - A penile fracture that extends into it can tear the urethra: blood at the meatus or difficulty passing urine ## Key facts **Where** Single ventral erectile cylinder around the spongy urethra; the bulb behind is fixed to the perineal membrane under bulbospongiosus; ends in front as the glans **Blood supply** Artery of the bulb and urethral artery (internal pudendal); dorsal arteries to the glans **Nerve** Cavernous nerves (parasympathetic, pelvic splanchnic S2–S4) for erection; sympathetic (T11–L2) for detumescence; [dorsal nerve of penis](https://durgical.com/en/anatomy/dorsal-nerve-of-penis/) (pudendal, S2–S4) for sensation **Function** Thin tunica keeps it compressible in erection so the urethra stays open; bulbospongiosus squeezes the bulb to expel semen and the last drops of urine ## Relations **Contents** [Spongy urethra](https://durgical.com/en/anatomy/spongy-urethra/), running through its centre **Above** [Corpora cavernosa](https://durgical.com/en/anatomy/corpus-cavernosum-of-penis/) along the shaft, with the corpus spongiosum in the groove beneath them **Superficial** [Bulbospongiosus](https://durgical.com/en/anatomy/bulbospongiosus-muscle/) over the bulb; Buck fascia, dartos and [skin](https://durgical.com/en/anatomy/skin/) along the shaft **Behind** The bulb rests on the [perineal membrane](https://durgical.com/en/anatomy/perineal-membrane/), just in front of the [perineal body](https://durgical.com/en/anatomy/perineal-body/) **In front** Expands into the [glans penis](https://durgical.com/en/anatomy/glans-of-penis/), which caps the blunt ends of the corpora cavernosa ## How to find it Felt as the softer ridge along the underside of the shaft; in the perineum the bulb is felt in the midline behind the scrotum. ## On imaging Urethral ultrasound shows its thickness and scarring around a stricture; on MRI the bulb is seen in the midline of the perineum. ## Common problems - Scarring of it and the urethra causes a urethral stricture. ## How it is diagnosed Examination; Doppler ultrasound when needed. ## Treatment - Depends on the cause; a penile fracture is repaired surgically. ## Clinical notes - Bulbar urethroplasty: the bulbospongiosus is split and the bulb mobilized to reach the stricture, which is excised and rejoined or widened with a buccal mucosa graft - Its bulb is fed by the artery of the bulb, a branch of the [internal pudendal artery](https://durgical.com/en/anatomy/internal-pudendal-artery/), which bleeds briskly when the bulb is mobilized in urethroplasty or perineal surgery ## Development Forms from tissue around the urethral folds as they fuse on the underside of the genital tubercle; in hypospadias it is often poorly formed beyond the meatus, with fibrous tissue that bends the penis downward (chordee). ## Related conditions - [Hypospadias](https://durgical.com/en/conditions/hypospadias/) - [Peyronie disease](https://durgical.com/en/conditions/peyronie-disease/) - [Priapism](https://durgical.com/en/conditions/priapism/) ## Test yourself Think of the answer, then tap the question to see it. ## What runs through the corpus spongiosum, and why does it stay softer in erection? The spongy urethra; its thin tunica keeps it compressible so the urethra stays open for semen. ## Which part of the corpus spongiosum is crushed in straddle injuries? The bulb, lying on the perineal membrane behind the scrotum, crushed against the pubic arch. ## What is spongiofibrosis, and why does it matter? Scarring of the corpus spongiosum around a urethral stricture; it sets the stricture's depth and length and whether urethroplasty is needed. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/anatomy/corpus-spongiosum-of-penis/) Educational information, not medical advice. For any symptom, see a health professional. ## Its names **Official Latin (TA2)** corpus spongiosum penis; bulbus penis **Official Spanish (DeCS)** Cuerpo esponjoso del pene **English (TA2)** Corpus spongiosum of penis **Also called** bulb of penis (back end) ## Related - [Spongy urethra](https://durgical.com/en/anatomy/spongy-urethra/) - [Glans penis](https://durgical.com/en/anatomy/glans-of-penis/) - [Bulbospongiosus](https://durgical.com/en/anatomy/bulbospongiosus-muscle/) - [Corpora cavernosa](https://durgical.com/en/anatomy/corpus-cavernosum-of-penis/) - [Internal pudendal artery](https://durgical.com/en/anatomy/internal-pudendal-artery/) Sources: [Anatomy, Abdomen and Pelvis, Penis](https://www.ncbi.nlm.nih.gov/books/NBK482236/). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/anatomy/corpus-spongiosum-of-penis/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/anatomy/corpus-spongiosum-of-penis/