Urinary System

Urine and Its Formation

What muscles control urination?

The walls of the urinary bladder have three layers: 1) a mucosa layer made of transitional epithelium; 2) connective tissue; and 3) detrusor muscle, composed of smooth muscle fibers arranged in both longitudinal and circular layers. It is the contraction of the detrusor muscle that compresses the bladder when voiding urine.


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