Final answer:
The external urethral sphincter muscle and bulbourethral glands are associated with the membranous urethra of the male urethra.
Step-by-step explanation:
The external urethral sphincter muscle and bulbourethral glands are associated with the membranous urethra of the male urethra. The external urethral sphincter muscle is responsible for voluntary control of urine flow, while the bulbourethral glands produce and secrete mucus into the urethra for lubrication and pH buffering during sexual stimulation.