Which of the following are considered accessory glands in the male reproductive system?

The accessory glands in the male reproductive system include the bulbourethral glands and the seminal vesicles. These glands play crucial roles in the production of seminal fluid, which nourishes and transports sperm during ejaculation.

The bulbourethral glands, also known as Cowper's glands, secrete a pre-ejaculatory fluid that helps lubricate the urethra and neutralizes any acidity, providing a more favorable environment for sperm. The seminal vesicles produce a significant portion of the seminal fluid, which includes fructose and other substances that provide energy to sperm and help facilitate their motility.

The other options contain components that do not fit the definition of accessory glands. The testes are primary reproductive organs responsible for sperm production and hormone secretion, while the prostate gland, although it contributes to seminal fluid, is more often classified as a principal gland rather than an accessory one in this context. The epididymis and vas deferens are part of the sperm transportation pathway and are not classified as glands. Lastly, the pituitary and adrenal glands are endocrine glands that regulate hormones but do not have a direct role in the male reproductive system in terms of accessory gland function.