When most guys think about a prostate exam, at least their first one, what usually comes to mind is one jokey, adolescent concern: The doctor's going to stick a finger in your butt.

However, there's more going on with prostate exams than a brief, if awkward, digital exploration of the prostate, a muscular gland about the size of a walnut located beneath a man's bladder. The prostate surrounds the urethra, and its main job is to produce seminal fluid, which is mixed with sperm before being ejaculated through the penis.

Several tests can help determine the health of the prostate. To alleviate concerns, here's a breakdown of the various types of prostate exams, what they're for and what they can tell you and your clinician about your health.

The digital rectal exam