The floor of the bladder has a smooth triangular region called the trigone region - with two corners at the ureterovesical junctions and the third corner being the internal urethral orifice, where the bladder meets the urethra.
Jesus Christ, Mary Mother of Satan's left nipple, it's like my hand is made entirely out of urethras, and each and every one is having a red hot catheter put in and ripped out five times every second.
We also talked about the anatomy of storing and excreting urine — from the ureters to the urethra — and we went over the nervous system's role in controlling the act of urination.
Acute pyelonephritis is most often caused by ascending infection: meaning bacteria start by colonizing the urethra and bladder, which would be a lower urinary tract infection, and make their way up the ureter to the kidney.
And finally we have the pea-sized bulbo-urethral glands below the prostate, that secrete a clear mucus that drains into the urethra to clear out any acidic urine prior to ejeculation.