by Judson Brandeis

Everything You Need To Know About Male Penile Anatomy
Us men spend so much of our lives obsessing about our penises and other sexual organs, but how much do we really know? I am a board-certified urologist specializing in sexual medicine for 25 years. I have straightened penises, scoped penises, injected penises, circumcised penises, and placed implants in penises. I have repaired fractured penises, fixed erections that won’t go down, treated dog and human bites, removed crack pipes up the urethra (yup), and even repaired attempts at self-removal (oh no!) and self-circumcision (really). The truth is usually stranger than fiction.

My passion is educating patients and physicians, and I would like to share some of that knowledge with you with an educational series. This article will go deeply into your penile anatomy. The next time I will describe what happens when you get an erection. Following that, I will discuss the scrotum and testicles and then the bladder and prostate. If the PornHub readers enjoy these articles, I will continue with a discussion of women’s anatomy and physiology. Please let PornHub Wellness know if you appreciate these posts and share them with your friends. If you are interested in learning about the cutting edge of sexual medicine, including the five clinical trials I am running at my office in Northern California, please visit me at I am running the most extensive multi-site study ever attempted on GAINSWave therapy for the improvement of erectile function, a trial of non-invasive penile elongation, a novel technology using HIFEM to improve the intensity and duration of orgasms, and testing a transdermal lotion to enhance erections

The Penis
The penis is composed of three lined cylinders nestled together in a sheath of connective tissue. The left and right erectile bodies, called the corpora cavernosa, are critical for erections. The corpora cavernosa fill up with blood during an erection and are responsible for the rigidity of the penis. The best research on penis size estimates that the average erect penis is 5.2 inches long and 4.6 inches in circumference. There are techniques to increase the girth of the penis, including injection of fat or fillers and a silicone implant, but no one has figured out how to increase the length of the penis.

Everything You Need To Know About Male Penile Anatomy

When the penis is not erect, the corpora are roughly the same diameter as the other tube, the corpus spongiosum. For this reason, when injecting medication in the flaccid penis to create an artificial erection, I inject at the two and ten o’clock positions. During an erection, the corpora cavernosa enlarge to a much greater extent than the corpus spongiosum. Therefore, with an erect penis, injections are at the three and nine o’clock position. This anatomical difference is critical for men who use Trimix injections to achieve an erection.

Trimix is a combination of three medications that, when injected into the penile shaft, cause the arteries to dilate and pump blood into the penis, causing a prolonged rigid erection. Men who have had prostate surgery or severe diabetes sometimes need to do this order to get a rigid erection. If the erection does not return to the flaccid state following ejaculation, the man is said to have priapism, named after the Greek God Priapus, a minor fertility god with a massive and permanent erection. Priapus was the son of Dionysus and Aphrodite, but the gods did not want Priapus to live with them on Olympus, so his parents left him on a hillside on Earth. They were probably jealous. Priapism is painful and dangerous. If you suspect priapism, take Sudafed. If this does not help and your erection lasts for more than 4 hours, seek immediate medical attention, or you risk permanent penis damage. Contrary to the advertisements, PDE-5 inhibitors like Viagra will not cause priapism. Common causes included Trimix injections, cocaine, antidepressant including Trazadone, and sickle cell anemia.

The head of the penis is called the glans. It is covered by the foreskin (or prepuce) unless a man has been circumcised. The area on the underside of the penis where the foreskin attaches is called the frenulum. This area is where the nerves gather and is the most sensitive area of the penis. The rounded base of the glans is called the corona.

Everything You Need To Know About Male Penile Anatomy

The corpora are attached to the pelvis along the pelvic arch so that half of the penis is not visible. If anyone asks how long your penis is, take the erect length and multiply by two. If someone challenges you and tells you that your penis is not as long as you just told them, you can say that Dr. Brandeis claims that half of the length of the penis is on the outside, and the other half is on the inside.

Everything You Need To Know About Male Penile Anatomy

Another essential structure related to the corpora is the suspensory ligament. This connective tissue hangs on the underside of the pubic bone and attaches to the mid-penis. The purpose of the suspensory ligament is the allow the penis to rise when it is erect; otherwise, your penis would at the wrong angle for penetration. There were some shady Beverly Hills doctors years ago who tricked men into getting surgery to ‘lengthen the penis’ by cutting the suspensory ligament. This operation made the penis hang lower when flaccid, but when the penis was erect, it was the same size but pointed down. Remember, I told you that half of the penis is on the inside, and half is on the outside and that no one has figured out how to make the penis longer. Six months after the surgery, the suspensory ligament incision created a scar that restricted the stretching of the penis and made it shorter. I have seen too many men in my office with this problem, so I created the P-LONG study, which is testing a natural way for men to increase the length and girth of their penises using growth factors which are without any significant risks or downside. If you are interested in this study, please visit the P-LONG page on my website under the research tab.

Everything You Need To Know About Male Penile Anatomy

The corpora cavernosum is lined by the tunica albuginea, which is one of the most durable lining tissue in the body that is still stretchy. The blood pressure in the penis during an erection is higher than systemic blood pressure, and the penis gets banged around during intercourse, so the tunica albuginea has to be tough. The lining of the tunica albuginea is made of collagen, which under the microscope looks like a box of uncooked spaghetti. In the penis, these fibers run lengthwise along the penis as well as in a circular fashion. That way, the penis can increase in length and girth. The collagen fibers are intermixed with stretchy elastic fibers, which make up about 5% of the total. The corpus spongiosum has some erectile tissue but does not have the same arrangement of collagen fibers.

The tunica albuginea is tough, but in extreme circumstances, a man can have a penile fracture, which is where this lining tissue ruptures and blood oozes through the opening. This unfortunate injury usually occurs during aggressive intercourse when the woman is on top. Sometimes this requires surgery to repair the leak and frequently results in scar tissue that causes shortening and curvature of the penis called Peyronie’s Disease. If you are having rough sex and hear a snap and your erection goes away quickly, your penis swells and becomes black and blue, go to the nearest urologist or emergency room as soon as possible to avoid further damage.

The corpora fill with blood during an erection and can expand up to five times their original size. Initially, the penile arteries pump blood into the penis, and emissary veins drain the blood out of the penis. However, as the corporal cylinders expand with arterial blood pressure, they pinch off the veins that exit the corpora and trap the arterial blood in the erect penis. Men who are not able to keep a full erection frequently use constricting rings to keep the venous blood from leaking out. When the pressure inside the shaft rises higher than the blood pressure in the rest of the body, arterial blood flow to the penis decreases. Finally, the penis becomes rigid enough for penetration and rises into the erect position. The penis needs such high blood pressure because it is the only organ in the body with skin but no skeletal muscle, and the only organ in the body that moves entirely based on blood flow.

The third cylinder of the penis is at the bottom or ventral aspect of the penis and is called the corpus spongiosum. The urethra, the tube that you urinate through, runs through the middle of the corpus spongiosum. The head of the penis, also known as the glans, is connected to the corpus spongiosum. The blood flows in the spongy tissues around the urethra and travels to the glans. The tip of the penis where a man urinates and ejaculates thru is called the meatus. When a man has a penile implant, the implant sits in the corpora cavernosa and does not extend into the glans. For that reason, men with penile implants can have difficulty with penetration because the head of the penis is floppy.

Circulation To The Penis: The Long And Winding Road …
When the heart pumps, the first place the blood goes is back to the heart through the coronary arteries. Then the blood goes to the brain, and then the arms, the liver, the kidneys, the intestines, then the blood splits into left and right iliac arteries and then divides again into the leg and the pelvis. In the pelvis, the blood goes to the tailbone, buttock muscle, the bladder, the prostate, and finally, the blood goes through the internal pudendal artery to the penis. The penis and the toes are the two last places in the body to get blood. The penile arteries are 1 mm in size. The coronary arteries to the heart are 3 to 4 mm, which is why men develop erectile dysfunction 5 to 10 years before they develop heart disease, but also why erectile dysfunction is an early warning sign for problems with your heart.

Everything You Need To Know About Male Penile Anatomy

Blood gets pumped under pressure through the deep cavernosal artery, which is the middle branch of the penile artery. This artery runs in the middle of the corpora cavernosa and gives rise to countless tiny side branches, which lead into chambers that fill up with blood. When I open the penis during surgery, it has the appearance of a delicate sponge. The chambers are lined with the endothelium, a specialized layer of cells that keeps the blood from clotting in the penis during an erection. Just on the other side of the endothelium is a layer of smooth muscle. When this muscle relaxes, it allows the chambers to fill up with blood increasing the pressure in the corpora. As this occurs, the small veins that return the blood to the body get pinched off, and the penis becomes rigid. Some men have a venous leak, which means that despite how high the pressures get in the penis, the veins will drain blood out of the penis continuously so that a rigid erection necessary for penetration is not possible. In this case, a penile constricting ring helps keep blood in the penis to maintain a rigid erection. Also, GAINSWave therapy can help increase the arterial vascular pressure in the corporal bodies of the penis, which can restrict venous outflow.

As a man reaches orgasm, the body produces adrenaline, which constricts the arteries and vascular spaces in the penis. Vascular constriction leads to rapid detumescence, or blood leaving the penis. When a man ejaculates, the sperm combines with semen from the prostate and the seminal vesicles. A typical ejaculation in a young man contains 350 million sperm and makes up 10% of the ejaculate. The remaining 90% is semen, which is made by the prostate and the seminal vesicles. The yellow color of semen comes from the seminal vesicles and contains amino acids, citrate, potassium, phosphorus, enzymes, proteins, Vitamin C, and Fructose. The white and watery secretions are from the prostate. Prostate secretions transform the semen from a liquid into a gel that will not fall out of the vagina, and then 20 minutes later, the prostate secretions cause the semen to become more liquid so that the sperm can more easily swim to the egg.

During ejaculation, the muscles at the base of the penis rhythmically contract. Since these muscles, called the bulbospongiosus and ischiocavernosus, surround the urethral tube, the ejaculate spurts out thru the urethral meatus. The contractions of these muscles are what men feel as pleasure during orgasm. When these muscles are squeezing during orgasm, the pressure in the corpora and corpora spongiosum goes even higher, giving men a throbbing sensation in their penis.

By doing Kegel exercises to strengthen the pelvic floor, men can improve the strength and intensity of orgasm. is a company that has an online platform to teach men how to strengthen these muscles.


If you are looking to learn more about your sexual health and wellness in the Columbus Ohio Metro area, contact us today at Elite Body and Laser to learn more at 614-334-4944.