Logo

    External Urethral Meatus

    Reviewed by our medical team

    External urethral opening.

    1. Overview

    The external urethral meatus, also known as the external urethral orifice, is the terminal opening of the urethra through which urine is expelled from the body. It represents the final structure of the urinary tract and marks the boundary between internal urinary anatomy and the external environment. Though small in size, its position and structure vary between males and females and it has important clinical relevance in urology and gynecology.

    2. Location

    In Males:

    The external urethral meatus is located at the tip of the glans penis, opening at the navicular fossa at the distal end of the spongy (penile) urethra. It lies in the sagittal plane and appears as a vertical slit. It is surrounded by the glans and is positioned ventrally when the penis is flaccid.

    In Females:

    The external urethral meatus is located in the vestibule of the vulva, just anterior to the vaginal opening and posterior to the clitoris. It lies between the labia minora and is often marked by a small mucosal elevation or fold.

    3. Structure

    The structure of the external urethral meatus consists of the following:

    • Mucosal Lining: Stratified squamous epithelium, continuous with the inner urethral lining.

    • Sphincteric Support: Though no separate external sphincter is located at the meatus itself, it functions in coordination with the external urethral sphincter (more proximal) during voluntary urination.

    • Surrounding Tissue: In males, embedded within the glans penis; in females, surrounded by vestibular and periurethral tissue.

    The meatus is typically 2–5 mm in diameter but may vary due to congenital or pathological conditions.

    4. Function

    The external urethral meatus serves as the final exit point for urine from the urinary tract. Its primary functions include:

    • Urine Elimination: Acts as the passage for urine to exit the body.

    • Direction Control: Particularly in males, it helps direct the urinary stream.

    • Barrier Role: Helps prevent external pathogens from entering the urinary tract.

    5. Physiological Role(s)

    While largely passive in function, the meatus contributes to the broader regulation of urination and protection:

    • Maintains Sterility: The mucosa and external location help minimize upward bacterial invasion.

    • Part of Continence Mechanism: Works with distal urethral structures to ensure effective closure until voluntary voiding occurs.

    • Urinary Stream Modulation: A properly shaped meatus helps maintain a directed, unobstructed flow during micturition.

    6. Clinical Significance

    Meatal Stenosis

    A narrowing of the external urethral meatus, most commonly seen in:

    • Uncircumcised males (post-hypospadias repair)

    • Patients with chronic irritation or infection

    Symptoms include:

    • Weak or split urinary stream

    • Straining during urination

    • Incomplete bladder emptying

    Treatment may involve meatotomy (surgical widening).

    Hypospadias and Epispadias

    Congenital anomalies where the external meatus is abnormally placed:

    • Hypospadias: Meatus is located on the underside of the penis.

    • Epispadias: Meatus opens on the dorsal (upper) side.

    Surgical correction is usually required for normal function and appearance.

    Urinary Tract Infections (UTIs)

    In females, the proximity of the external urethral meatus to the anus and vagina makes it a common entry point for bacteria, especially E. coli. Hygiene, sexual activity, and anatomical abnormalities can influence infection risk.

    Catheterization and Instrumentation

    Proper identification of the meatus is essential for safe urethral catheterization. Errors may cause:

    • Urethral trauma

    • False passages

    • Infections

    In males, special care must be taken to avoid iatrogenic injury to the navicular fossa.

    Meatal Caruncle (Females)

    A benign fleshy outgrowth near the meatus, often seen in postmenopausal women. May cause discomfort, bleeding, or mimic a tumor. Treatment includes topical estrogen or surgical excision if symptomatic.

    Sexual Health Relevance

    The meatus can be a site of infection or irritation due to:

    • Sexually transmitted infections (e.g., gonorrhea, chlamydia)

    • Trauma from sexual activity

    Symptoms may include dysuria, discharge, or local erythema.

    Did you know? Your kidneys receive about 20% of the body's blood supply at any given time.