| Inside the gland, multiple follicle pouches join to form excretory ducts, which empty into the urethra. |
| At the same time, the seminal vesicles and prostate gland contract and release seminal fluid into the urethra. |
| Most often the blockage occurs in the urethra after a stone or a mixture of crystal, mucus, and other organic material forms a plug. |
| The corpus spongiosum is a chamber that surrounds the urethra and becomes engorged with blood during an erection. |
| If a stone is lodged in the ureter, a flexible narrow instrument called a cystoscope can be passed up through the urethra and bladder. |
| This is a long, thin telescope instrument with a light and lens on the end, which is passed into the bladder through the urethra. |
