URETHRA -

• It is common duct as sperms & urine both pass from it.
• It receives juices of prostatic gland & cowper's gland.
• Urethra is 20 cm long, passes through the penis, it's lumen is star shaped.
• It has 3 regions -

                (i) A short proximal prostatic urethra surround by prostate gland.

                (ii) A very short middle membranous urethra without any covering.

                (iii) A long distal penial urethra.

• Urethra has 2 sphintors. Internal sphincter is of smooth muscle fibres at its beginning.
• External sphinctor is of straited muscle fibres around its membranous part.