Anatomy 101: A Guide to Your Junk

Meat and potatoes, twig and berries, turkey neck and dumplings, dangly bits… That’s right folks, today we’re giving an anatomy lesson on the dick and balls. I’m always surprised by how little people know about their junk. Blame it on the Puritans if you like, but Americans in general seem very hesitant to look at their genitals, touch their genitals, or talk about their genitals. If we’re lucky, we get a brief and awkward sex ed lesson in school, but most information we have comes from hearsay or the internet, which can be dubious information at best.

Having a good understanding of male genital anatomy is a necessary part of good male reproductive health and good health in general. And for our conversation today, we’re going to be talking to all people with a penile shaft and scrotum anatomy —not just men. It’s important to note that a person’s genitals don’t necessarily translate to that person’s gender identity and vice versa. If you have a penis and scrotum, but you don’t identify as male, this article is for you, too. We want everyone to have working knowledge of the equipment they’re carrying.

At the risk of triggering unpleasant middle-school-science-class-like flashbacks, we’re including a labeled diagram to aid in the discussion.

We don’t expect you to be a fully licensed healthcare practitioner after this penis structure 101 article, so we’ll try to keep our lesson short, sweet, and easy to understand. However, the parts of the penis and balls that you know and love are just a fraction of the amazing anatomy that makes up these sexual organs. The penis is like an iceberg in that way. We only see the tip. (Insert just-the-tip joke here).

Most people are familiar with the parts of the penis that we see—the glans penis (a.k.a. the head) and the penile shaft —but the penis actually reaches way down into the ischiopubic rami , which is part of your pelvis. It’s composed of three chambers, including one corpus spongiosum chamber, the erectile tissue that surrounds the urethra function , and two corpus cavernosum chambers, which fill with blood during an erection. These two corpora cavernosa chambers are what extend deep into the pelvis.

In addition, the penis is home to several important penile blood supply structures, including the dorsal artery , cavernosal arteries , and superficial and deep dorsal veins . The cavernosal arteries carry blood into the penis to fill the corpus cavernosum , which causes the penis to become erect and collapse the surrounding veins. After ejaculation, the veins carry blood from the penis back to the body, causing the penis to become flaccid once more.

The urethra is a tube that runs down the underside of the penis, allowing urine and semen to exit the body. Proper hygiene is crucial to avoid infections. If you have a foreskin , gently pull it back and clean underneath to prevent smegma prevention buildup, which can lead to irritation and infection.

Along with the penis, the scrotum anatomy makes up the remainder of external sex anatomy. The scrotum houses the testicular function , regulating temperature to optimize male reproductive health . The scrotum pulls the testicles closer to the body when it’s cold and lets them hang lower when it’s warm.

The testicular function includes sperm production , hormone regulation, and male fertility . The epididymis , located behind the testicles , transports sperm to the vas deferens , which carries sperm into the seminal fluid for ejaculation.

Let’s talk about the all-stars of male anatomy: the penis and testicles . These VIPs handle three of the most fantastic and fun functions of the human body— sexual pleasure, fertility, and urinary function . The penis is the headliner when it comes to penetrative sex , and when it’s aroused and ready for action, it can enter a vagina or an anus. But let’s be real—penetration isn’t the only way to experience sensation . The penis, especially the glans penis , is packed with nerve endings that heighten pleasure, making it a prime player in all types of sexual activity.

That said, for all its versatility, the penis isn’t indestructible. A little too much enthusiasm (or a poorly timed thrust) can lead to a penile fracture —yes, that’s a real thing. The erectile tissue inside the penis, known as the corpus cavernosum and corpus spongiosum , is responsible for getting and keeping things firm. But if you thrust too hard and miss your target, these delicate structures can take serious damage. If that happens, expect pain, bruising, swelling, and—if left untreated—long-term deformities or even erectile dysfunction . So go ahead and be adventurous, but maybe don’t treat your penis like a battering ram.

Beyond bringing the fun, the penis also has a practical side, handling urinary function and ejaculation. Peeing is pretty straightforward—your kidneys do their filtering thing, and urine exits stage left via the urethra. That urethra also happens to run through the prostate , and as you get older, this gland can swell up like an unwelcome party crasher, making it harder to go with the flow. Urinary function can also be disrupted by infections, scarring, or other medical conditions, so if you’re dealing with pain, burning, or a weak stream, don’t ignore it—check in with a doctor.

Now onto our favorite topic: ejaculation. When you climax, semen is launched from the penis in a glorious grand finale. But semen isn’t just sperm—it’s an elite cocktail of water, plasma, mucus, calcium, lactic acid, glucose, fructose, magnesium, protein, zinc, and potassium. Basically, it’s a nutrient-packed VIP package for fertility . Ejaculation is a team effort, requiring the penis, testicles, epididymis, prostate, and vas deferens to work in harmony. If you want to boost your semen volume and enhance the experience, Popstar’s Volume + Taste supplement is here to help.

Speaking of sperm, the testicles are where all the magic happens. This is where sperm cells are produced, and while they’re essential for fertility , modern medicine has given us plenty of other ways to unite sperm and egg—so penetrative sex isn’t the only route to fatherhood. But let’s not forget that the scrotum isn’t just a sperm factory—it’s also packed with nerve endings , making it a prime erogenous zone . A little attention down there can go a long way in the sexual pleasure department.

Bottom line? Take care of your MVPs, be mindful of their limits, and when in doubt, give them a little extra support—whether that’s supplements, better hydration, or some strategic lube from Popstar. You only get one set, so treat them right.

Your genitals are amazing in a million different ways, but occasionally things can go wrong. It’s important to be intimately familiar with your penis and scrotum so that you know how they normally look and feel. I recommend doing a self-examination about once a month to see if there are any changes. Warning signs to be on the lookout for are changes in size, swelling, pain, lumps, bumps, dark spots, lesions, cysts and redness. However, this is not an exhaustive list, so make sure to pay attention to any deviations from the norm. 

While issues that we see in my medical practice are usually benign, cancer and other serious conditions do occur. Testicular cancer is often painless, so if something seems off, but it doesn’t hurt, don’t assume that it’s nothing. Cancer often presents as a hard lump, while pain, inflammation, and/or swelling often signal an infection. Luckily your body does have natural protections like pubic hair. Although pubic hairstyles come and go, remember that this patch of fur is an important part of genitalia that actually helps to prevent against bacterial infections and irritation caused by sex. That means you might want to think twice before opting for that full Brazilian waxed look.

Other threats to your genitals come in the form of sexually transmitted infections or STIs. Common STIs include gonorrhea, herpes, human immunodeficiency virus (HIV), human papillomavirus (HPV), chlamydia, molluscum, syphilis, hepatitis and trichomoniasis. These STIs can present with symptoms of burning, discharge, lesions and pain. However, some STIs show no symptoms at all. Your best defense against STIs and penile health complications that come with them is to practice safe sex and get tested regularly. STI testing can be done at your doctor’s office or at low-cost and free health clinics nationwide. There are even at-home STI testing kits!

No matter what pet names you choose to use for your genitals, make sure you become acquainted with them on an intimate level. There is nothing shameful or gross about touching, feeling, looking at or examining your private parts. It’s not only important to know your bits and pieces, but it is also necessary for your overall health and wellbeing. I promise, your John Thomas and his yam bag will thank you.