The ureters

The ureters

These are the tubes that convey urine from the kidneys to the urinary bladder; the upper end is funnel-shape where it merges with the pelvis of the kidneys. Each tube is about 25-30cm long 1 and 3mm in diameter. It runs from the renal hilum to the posterior

wall of the bladder, pass down the posterior wall of the abdomen towards the pelvis, so remain outside the peritoneal cavity, beside the uterine cervix to enter the bladder from behind.

Structure

The ureter is made up of three layers.

·              Transitional Epithelium: This forms the lining of theureter and is arranged in longitudinal folds.

·              Muscular Layer: This layer is composed of three fibers;inner longitudinal fibers, middle circular fibers and outer longitudinal fibers.

·              Outer Coat: This is made up of fibrous connective tissue which is continuous with the fibrous tissue of the kidneys. It is a protective layer.

Blood Supply

The upper part: by the renal artery in the pelvic portion- Common Iliac, internal iliac, uterine and vesical arteries, Venous Returns- Corresponding veins.

Lymphatic Drainage- Internal and external common iliac lymph nodes.

Nerve Supply- Aortic, Renal superior and inferior hyponastic plexus. Sympathetic and parasympathetic nerves.

Effect of Pregnancy on the Ureters

Pregnancy hormone e.g. progesterone relaxes the walls of the ureters. This results in dilatation and linking of the ureters which tends to slow down the flow of urine or causes stasis. This increases the risk of infection in pregnancy.