Logo

    Related Topics

    From Urinary System

    Bladder Neck
    Region surrounding internal urethral orifice.
    Arcuate Arteries
    Arch over the base of pyramids.
    Minor Calyces
    Receive urine from renal papillae.
    Proximal Convoluted Tubule
    Reabsorbs water, ions, and nutrients.
    Renal Cortex
    Outer region of the kidney where filtration begins.
    Papillary Duct
    Drains urine into minor calyx.
    Renal Artery
    Supplies oxygenated blood to kidney.
    Internal Urethral Sphincter
    Involuntary control of urine release.
    Ureteral Openings
    Where ureters drain into bladder.
    Bladder Peritoneum
    Covers superior bladder surface.
    Urachus
    Fetal remnant connecting bladder to umbilicus.
    Renal Pelvis
    Funnel-shaped basin collecting urine into ureter.
    Ureterovesical Junction
    Ureter entry into bladder.
    Urethra
    Carries urine out of the body.
    Urogenital Diaphragm
    Supports pelvic organs, surrounds sphincter.
    Major Calyces
    Formed by union of minor calyces.
    Internal Urethral Orifice
    Opening from bladder to urethra.
    Trigone
    Triangle between ureteral openings and urethra.
    Peritubular Capillaries
    Surround cortical nephrons.
    Renal Fascia
    Connective tissue anchoring kidney.
    Hilum of Kidney
    Entry/exit site for vessels, nerves, and ureter.
    Interlobar Arteries
    Run between renal pyramids.
    Renal Medulla
    Inner region of kidney containing renal pyramids.
    Median Umbilical Ligament
    Remnant of embryonic urachus.
    Pelvic Floor Muscles
    Support bladder and urethra.

    Ureters

    Reviewed by our medical team

    Transport urine to bladder.

    1. Overview

    The ureters are paired muscular tubes responsible for transporting urine from the renal pelvis of each kidney to the urinary bladder. Measuring approximately 25–30 cm in adults, the ureters operate through coordinated peristaltic contractions, ensuring unidirectional urine flow under low pressure. They are anatomically and functionally significant, with several physiological narrowing points that are clinically relevant for conditions like urolithiasis (kidney stones).

    2. Location

    Each ureter runs vertically through the retroperitoneal space, passing along the posterior abdominal wall and into the pelvis. Key anatomical relationships include:

    • Origin: From the renal pelvis at the ureteropelvic junction (UPJ).

    • Course: Descends anterior to the psoas major muscle, crosses over the iliac vessels at the pelvic brim.

    • Termination: Enters the bladder wall obliquely at the ureterovesical junction (UVJ).

    • Male pelvis: Crossed by the vas deferens.

    • Female pelvis: Crosses under the uterine artery (“water under the bridge” relationship).

    3. Structure

    The ureter wall is composed of three concentric layers:

    • Mucosa: Lined with transitional epithelium (urothelium) that permits stretching without leakage.

    • Muscularis:

      • Upper 2/3: Inner longitudinal and outer circular smooth muscle.

      • Lower 1/3: Adds an outer longitudinal layer (three-layered arrangement).

    • Adventitia: Outer connective tissue layer that anchors the ureter to surrounding structures and contains blood vessels, lymphatics, and nerves.

    Three physiologic narrowings occur along its path:

    1. Ureteropelvic junction (UPJ)

    2. Crossing over the iliac vessels (pelvic brim)

    3. Ureterovesical junction (UVJ)

    4. Function

    The primary function of the ureters is to:

    • Transport urine: Move urine from kidneys to bladder via rhythmic, unidirectional peristalsis.

    • Prevent backflow: The oblique entry into the bladder wall acts as a functional valve, closing during bladder contraction.

    5. Physiological Role(s)

    Ureters contribute significantly to urinary homeostasis:

    • Pressure buffering: Maintain low-pressure transit of urine without reflux, preserving kidney function.

    • Neurogenic control: Innervated by sympathetic and parasympathetic fibers, allowing reflex modulation of peristalsis.

    • Hormonal responsiveness: Ureteral tone and motility may be influenced by prostaglandins, antidiuretic hormone, and other local factors.

    • Sensory feedback: Mechanoreceptors detect distension and help trigger reflexes related to voiding and pain (e.g., during obstruction).

    6. Clinical Significance

    Urolithiasis (Kidney Stones)

    Stones often lodge at the three natural ureteral constrictions, especially the UVJ. Symptoms include:

    • Severe flank pain (renal colic)

    • Hematuria

    • Nausea and vomiting

    Diagnosis: CT scan (non-contrast), ultrasound. Management: hydration, pain control, lithotripsy, or ureteroscopy.

    Ureteral Obstruction

    May be caused by:

    • Stones, tumors, strictures, or external compression (e.g., from pelvic masses).

    Leads to hydronephrosis, infection, or renal damage if untreated. Managed via stents, nephrostomy, or surgical correction.

    Vesicoureteral Reflux (VUR)

    Occurs when the UVJ fails, allowing urine to reflux into the ureter and kidney. Common in children and associated with recurrent UTIs and renal scarring. Graded I–V on imaging (VCUG), with treatment options ranging from antibiotics to ureteral reimplantation.

    Ureteric Injury

    Can occur during pelvic or abdominal surgery (e.g., hysterectomy, colorectal surgery). Presents with flank pain, urine leakage, or fistula. Prompt diagnosis with imaging and surgical repair is critical.

    Ureterocele

    Cystic dilation of the distal ureter, often congenital. Can obstruct urine flow and is managed endoscopically or surgically.

    Duplicate Ureters

    Congenital duplication of ureters may cause ectopic drainage, obstruction, or reflux. Commonly identified in pediatric imaging. May require surgical correction depending on severity and symptoms.

    Imaging Relevance

    Ureters are evaluated using:

    • Ultrasound: To detect hydronephrosis.

    • CT Urography: Gold standard for stones or tumors.

    • IV Urogram / Retrograde Pyelogram: For anatomical delineation in complex cases.

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