Urology Book

Penile Disorders

  • Anatomy of the Penis

Urinary Incontinence


Anatomy of the PenisAka: Penile Anatomy, Penis, Erection


  1. Shaft of Penis
    1. Corpus Cavernosum (two)
      1. Two large columns of erectile tissue on penile dorsum
      2. Columns separated by septum of fibers
    2. Tunica albuginea
      1. Bands together the two columns of corpus cavernosa
    3. Lacunar space (Space of Smith)
      1. Surrounds tunica albuginea
      2. Intralacunar smooth muscle found within space
    4. Corpus spongiosum
      1. Located on ventral side (underside) of penis
      2. Does not contribute to penile rigidity
      3. Contains urethra
  2. Glans (Head) of Penis Innervation
    1. Sensation
      1. Pudendal nerve supplies dorsal nerves to penis
    2. Erectile function
      1. Parasympathetic input (excitatory)
        1. Nervi erigentes runs adjacent to prostate gland
        2. Parasympathetic nerves join at hilum of penis
        3. Nerves course through corpus cavernosa
      2. Sympathetic input (inhibitory)
        1. Sympathetic Nerves supplied by thoracolumbar plexus
  3. Vascular Supply of the Penis
    1. Arterial inflow
      1. Supplies glans penis and shaft of penis
      2. Branches of deep internal pudendeal arteries
        1. Common penile artery
        2. Bulbar artery
        3. Dorsal artery
        4. Urethral artery
        5. Cavernosal artery
    2. Venous drainage
      1. Superficial penile veins
        1. Superficial dorsal vein
      2. Intermediate penile veins
        1. Emissary vein
        2. Circumflex vein
        3. Deep dorsal vein
      3. Deep penile veins
        1. Hilar vein (Santorini's Plexus)
        2. Cavernosal vein
  4. Erection Physiology
    1. Step 1: Flaccid Penis
      1. Intralacunar (cavernosa) smooth muscle contracted
      2. Under Alpha adrenergic control (Norepinephrine)
    2. Step 2: Cavernous nerve stimulation (Parasympathetic)
      1. Alpha Adrenergic Receptor blockade
        1. Acetylcholine
        2. Vasoactive intestinal peptide (VIP)
        3. Prostaglandin (Prostacyclin system)
        4. Nitric oxide (nitrergic system)
          1. Released from nerve endings
          2. Activates guanosine triphosphate to produce cGMP
      2. cGMP causes smooth muscle relaxation
      3. Intralacunar (cavernosa) smooth muscle relaxes
    3. Step 3: Arterial Inflow increases
      1. Lacunar space dilates
      2. Helicine artery dilates
    4. Step 4: Venous outflow blocked
      1. Subtunical venules compressed
      2. Emissary veins (in tunica albuginea) compressed
    5. Step 5: Erection as lacunar space pools with blood
      1. Blood fills space rapidly with arterial dilation
      2. Blood trapped due to venous constriction
    6. Step 6: Ejaculation (Sympathetic Stimulation)
      1. Controlled by hypogastric plexus sympathetic impulse
    7. Step 7: Detumescence (Penis flaccid again)
      1. Decreased parasympathetic tone
      2. Baseline sympathetic tone maintained
  5. References
    1. Jordan (1999) Postgrad Med 105(2):131

Penile Diseases (C0030846)

Definition (MSH)Pathological processes involving the PENIS or its component tissues.
Definition (CSP)condition in which there is a deviation from or interruption of the normal structure or function of the penis.
ConceptsDisease or Syndrome (T047)
ICD9607, 607.9
EnglishDisease of penis, Disorder of penis, DISORDER PENIS, Disorders of penis, PENILE DIS, Penile Disease, Penile Diseases, Penile Disorder, Penile Disorders, penis, PENIS DIS, Penis Disease, Penis Diseases, PENIS DISORDER, Unspecified disorder of penis
Spanishenfermedad del pene, enfermedad peniana, trastorno del pene, trastorno peniano
Parent ConceptsDisorder of male reproductive system (C0236099), Genital Diseases, Male (C0017412), Penile Diseases (C0030846), MALE GENITAL ABNORMALITIES (C0549618), Penis finding (C0426330), Duplicate concept (C1274013)
Derived from the NIH UMLS (Unified Medical Language System)

Penile Erection (C0030847)

Definition (MSH)The state of the PENIS when the erectile tissue becomes filled or swollen (tumid) with BLOOD and causes the penis to become rigid and elevated. It is a complex process involving CENTRAL NERVOUS SYSTEM; PERIPHERAL NERVOUS SYSTEMS; HORMONES; SMOOTH MUSCLES; and vascular functions.
Definition (CSP)physiological response of penile erectile tissue engorging with blood due to male sexual arousal.
Definition (GO)The hardening, enlarging and rising of the penis which often occurs in the sexually aroused male and enables sexual intercourse. Achieved by increased inflow of blood into the vessels of erectile tissue, and decreased outflow. [GOC:jl, http://en.wikipedia.org/wiki/ "Wikipedia"]
Definition (NCI)The hardening, enlarging and rising of the penis which often occurs in the sexually aroused male.
ConceptsOrgan or Tissue Function (T042)
EnglishErectile, Erection, Penile Erection, penis erection
Spanishereccion peniana
Parent Conceptsgenital function (C0678884), penis (C0030851), Sex Behavior (C0036864), reproductive process in a multicellular organism (C1820179), reproductive physiological process (C0035150), Reproductive System Process (C1514870), Male sexual finding (C1291723)
Derived from the NIH UMLS (Unified Medical Language System)

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