Male reproductive organs (Male reproductive system)


The male reproductive system consists of the penis, testes, epididymis, ejaculatory ducts, prostate, and accessory glands. These organs function together to produce sperm and deliver semen from the testes via ejaculation. For more information on the embryological development of the male reproductive system, see development of the reproductive system.



Urination and release of semen

Gross anatomy [1][2]

Primarily composed of erectile tissue, blood vessels, nerves, and connective tissue



Course Supplies
Internal pudendal artery
  • External genitalia

Bulbourethral artery

Deep artery of the penis
  • Erectile tissue
Dorsal artery of the penis
Urethral artery
External pudendal artery


Vein Anatomy Drains into
Deep dorsal vein of the penis Prostatic and pelvic venous plexuses
Superficial dorsal vein of the penis → External pudendal veins → greater saphenous vein


Structure Lymph nodes Course
Perineum, penis, and scrotum Superficial inguinal lymph nodes external iliac nodespara-aortic nodes
Glans penis Deep inguinal lymph nodes internal iliac nodescommon iliac nodespara-aortic nodes
Corpora cavernosa Internal iliac nodes common iliac nodespara-aortic nodes


Innervation Structures Function
Parasympathetic Pelvic splanchnic nerves (S2-S4) Erection (see below)
Sympathetic Hypogastric nerve (T11-L4) Emission (see below)
Sensory Dorsal nerve of the penis (a branch of the pudendal nerve) Innervates the skin, prepuce, and glans

Point and Shoot": Parasympathetic Points it up (erection), Sympathetic Shoots out the semen (ejaculation).

Microscopic anatomy [1][2]

Embryology [1]

Testes, scrotum, and spermatic cord

Gross anatomy

Structure [1][2][4]

Remember the spermatic cord layers with “TIE turns into ICE”:
- Transversalis fascia Internal spermatic fascia
- Internal oblique → Cremasteric muscle and fascia
- External oblique → External spermatic fascia

Vasculature, lymphatics, and innervation of the testes and scrotum [4]

Testes Scrotum
  • Pampiniform venous plexus drains to testicular veinrenal vein (left) and inferior vena cava (right)
  • Scrotal veins drain to external pudendal vein


Autonomic Innervation

  • Abdominal aortic plexus
  • T10 → testicular plexus
Motor innervation
  • None
Sensory innervation

Microscopic anatomy

Microscopic anatomy [1][2]


  • Description: Undifferentiated germ cells lining the seminiferous tubules
    • Type A (dark): do not undergo mitosis
    • Type A (pale): form type B spermatogonia
    • Type B: undergo mitosis → mature into primary spermatocytes
  • Function: site of primary spermatocyte production

Sertoli cells

Leydig cells


Blood-testis barrier

Spermatogenesis and spermiogenesis

Spermatogenesis and spermiogenesis [1][2]



GONIUM is GOING be sperm: speramtogonia → spermatid. ZOON ZOOMS to the egg: mature spermatozoon travel to the egg.


Embryology [1]

Epididymis, ductus deferens, and accessory glands

Epididymis [1]

Ductus deferens [1]

Ejaculatory ducts [1]

Accessory glands

Prostate (see below)

Seminal vesicles [2]

Bulbourethral gland (Cowper gland) [2]

  • Gross anatomy: located in the deep perineal pouch within the urogenital diaphragm
  • Function: secretes mucus into the bulbar urethra for lubrication during ejaculation
  • Embryology: : derived from the pelvic portion of the urogenital sinus (differentiation requires DHT)

Prostate gland

An accessory gland of reproduction located at the base of the bladder and composed primarily of glandular, fibrous, and smooth muscle tissue.

Function [2]

Secretion of:

Gross anatomy [1][2]


Vasculature, lymphatics, and innervation of the prostate gland [3][6]



Sympathetic innervation
Parasympathetic innervation

Because of the prostate's lymphatic drainage to the para-aortic lymph nodes, prostate cancer often metastasizes to the lumbar spine.

Microscopic anatomy [8][9]

Embryology [8]


Male sexual response

There are three parts of the male sexual response: erection, emission, and ejaculation.

Erection [12][2][13]

PDE-5 inhibitors (e.g., sildenafil) inhibit hydrolysis of cGMP → ↑ NO → vasodilation → prolonged erection

Ejaculation [12][2][15]



Remember the ejaculatory pathway of sperm with SEVEn UP: Seminiferous tubules → Epididymis → Vas (ductus) deferens → Ejaculatory duct → Urethra → Penis

Innervation of male sexual response: Point, Squeeze, and Shoot
1. Parasympathetic → Point (erection)
2. Sympathetic → Squeeze (ejaculation)
3. Somatic (pudendal nerve) → Shoot (emission)

Clinical significance


Testes and scrotum



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  • 13. Cunningham GR, Rosen RC. Overview of male sexual dysfunction. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Last updated May 11, 2016. Accessed February 23, 2017.
  • 14. Jonas Boström, Anders Hogner, and Stefan Schmitt. Do Structurally Similar Ligands Bind in a Similar Fashion?. Journal of Medicinal Chemistry. 2006. url:
  • 15. Alwaal A, Breyer BN, Lue TF. Normal male sexual function: emphasis on orgasm and ejaculation. Fertil Steril. 2015; 104(5): pp. 1051–60. doi: 10.1016/j.fertnstert.2015.08.033.
last updated 11/19/2020
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