URETHRA
- It is a thin walled muscular tube that drains the urine from the urinary bladder and conveys it out of the body.
Male urethra:
-It is total length about 8 inches (20cm).
Histology:
(Same as the bladder)
Female urethra:
- It is about 1.5 inch (4 cm) long.
- It opens to the outside at the external urethral orifice which lies anterior to the vaginal opening (in the vestibule).
- It is embedded into the anterior wall of the vagina.
Vascular supply:
Arteries:
- intramural part: inferior vesical artery (from the internal iliac artery)
- pelvic part: uterine and vaginal arteries (from the internal iliac artery)
- perineal part: internal pudendal artery (from the internal iliac artery)
Veins:
- intramural part: vesical venous plexus (via the vesical veins to the internal iliac vein)
- pelvic part: vaginal venous plexus (via the vaginal veins to the internal iliac vein)
- perineal part: internal pudendal veins (to the internal iliac vein)
Lymphatic drainage: paravesical nodes (to the common, internal and external iliac nodes)
Sympathetic and parasympathetic, visceral sensory and (somatic) motor nerve fibers: vesical plexus