Andrew Siegel MD 2/16/2023
This is another encore entry, worthy of a second toss into cyberspace. This bookends last week’s blog, “Rocking but Rusty,” with Valentine’s Day sandwiched in between.
Erections are often taken for granted, thought of as a simple act of nature. Achieving a rigid erection is a complicated event that demands that numerous body systems work in tandem in a coordinated fashion. The symphony orchestra is used as a metaphor to help explain this complexity.
Image above created on DALL-E Open AI
Achieving an erection is a “symphony” that results from the interplay of four “orchestral sections”: nerves, blood vessels, erectile smooth muscle, and erectile skeletal muscle (pelvic floor muscles). The “conductor” of the orchestra is the brain (the main sex organ). Although each “musician” within the orchestral sections has a unique role, all work together harmoniously to create a beautiful “symphony.” If any individual musician or orchestral section is off key, the disharmony can cause the “symphony” to be flawed, resulting in a sub-par performance.
SECTIONS OF THE ORCHESTRA
Nerves: Think of the nerves as the string instruments (violin, viola, cello and double bass) vibrating in sync.
The penis has a rich supply of nerves that connect with the spinal cord and brain. Without these nerves and connections, the penis would not be able to experience sensation, cut off from the rest of the body and incapable of responding to touch or erotic stimulation. The paired cavernous nerves that convey the message to the penis to fill with blood are anatomically intimate with the prostate gland.
How things work when nerves are functioning well:
• When the penis is stimulated by touch, nerves relay information to spinal cord centers, which then relay the message to the penile arteries to increase blood flow, resulting in the penis becoming engorged with blood.
• Touch to the penis is also conveyed directly to the brain, enhancing the reflex spinal cord response.
• Erotic stimulation (visual cues, sounds, smells, touch, thoughts, memories, etc.) further stimulates the penis from excitatory nerve pathways that descend from the brain.
• With touch stimulation of the head of the penis, a reflex contraction of the pelvic floor muscles occurs, which causes more blood to flow into the penis, leading to a fully rigid erection.
Blood vessels: Think of the blood vessels as the percussion instruments (piano, xylophone, cymbals, drums, etc.) pulsing rhythmically.
Inflation of the penis is all about blood inflow and trapping. When there are issues with the influx or trapping of blood, it becomes challenging to obtain and/or maintain an erection.
How things work when the blood vessels are functioning well:
• With touch or erotic stimulation, the cavernous nerves convey the message to the penile arteries to relax, which increases penile blood flow.
Erectile smooth muscle: Think of the erectile smooth muscle as the woodwind instruments (piccolos, flutes, oboes, clarinets and bassoons).
The erectile smooth muscle within the sinuses of the erectile chambers governs the inflation/deflation status of the penis. When the smooth muscle is contracted (squeezed), the penis cannot inflate with blood, but when the muscle relaxes, blood gushes into the sinuses and inflates the penis.
As we age, smooth muscle in all arteries of the body stiffens, causing high blood pressure (essential hypertension); paralleling this, there is an age-related stiffness of the erectile smooth muscle, which can cause difficulty obtaining and/or maintaining an erection.
How things work when the erectile smooth muscle is functioning well:
• With touch or erotic stimulation, the smooth muscle within the sinuses of the erectile chambers relaxes, under control of the cavernous nerves, which allows blood to flow into and fill the sinuses.
• As the sinuses approach complete filling, veins that drain them are pinched, trapping blood within the sinuses.
• This smooth muscle relaxation results in penile blood pressure becoming equal with the systolic blood pressure (normally 120 millimeters) and an engorged penis, plump but not rigid.
Erectile skeletal muscles (pelvic floor muscles): Think of the erectile skeletal muscles as the brass instruments (trumpets, French horns, trombones, and tubas), which are capable of the loudest sounds in the orchestra. These instruments are particularly important to the most booming, powerful and exciting portions of the music, corresponding to the role of the pelvic floor muscles that maintain rigidity and drive ejaculation and climax.
The pelvic floor muscles are the “rigidity” muscles, necessary for transforming the plump penis into a rock-hard penis. These muscles surround and compress the deep, internal roots of the penis, causing backflow of pressurized blood into the penis, responsible for obtaining and maintaining full rigidity. When the penis is erect, it is the pelvic floor muscles that are responsible for the ability to lift one’s penis up and down as the muscles are contracted and relaxed. These muscles are also responsible for ejaculation—compressing the urethra rhythmically to cause the expulsion of semen.
An erection—in mechanical (hydraulic) terms—is when the penile blood inflow is maximized while outflow is minimized, resulting in an inflated and rigid penis. The pressure in the penis at the time of a fully rigid erection is greater than 200 millimeters, the only organ in the male body where high blood pressure is both acceptable and necessary for healthy function. If the systemic blood pressure was this high, it would be considered a “hypertensive crisis.” As an aside, this explains why blood pressure pills are the most common medications associated with erectile dysfunction.
How things work when the pelvic floor muscles are functioning well:
• With touch stimulation of the head of the penis, there is a reflex contraction of the pelvic floor muscles; every time the head of the penis is stimulated, the pelvic floor muscles reflexively contract.
• The pelvic floor muscles surround the roots of the penis and as they compress and squeeze the penile roots with each contraction, blood within the roots is forced back into the external penis. This pushes more blood into the penis and causes increased clamping of venous outflow, a tourniquet-like effect resulting in penile high blood pressure and full-fledged rigidity—a brass-hard penis.
Brain: Think of the brain as the conductor of the orchestra—the maestro—who has the vital role of unifying and coordinating the individual performers, setting the tempo, executing meter, “listening” critically and shaping the sound of the ensemble accordingly. The conductor is the key player and if he is having an off day and does not bring his “A” game, there will be disharmony in the orchestra and the symphony will be flat and unimpressive.
Psychological and emotional factors have a significant impact on erectile function. Mood, stress, anxiety, fears, interpersonal and relationship issues, etc.—acting via the mind-body connection and mediated via the release of neurochemicals—can influence erectile function for better or worse. Stress, for example, induces the adrenal glands to release a surge of adrenaline. Adrenaline constricts blood vessels, which has a negative effect on erections, the basis for the common occurrence of adrenaline-fueled performance anxiety.
In summary, an erection is a highly complex “symphony,” orchestrated by the main sex organ—the brain—and executed at the level of the penis via the individual performances of the “orchestral members” that comprise the orchestral sections—the nerves, blood vessels, erectile smooth muscle, and the erectile skeletal muscles. All orchestral members play a vital role in the creation of a magical synergy, resulting in a spirited, powerful, passionate performance that climaxes in a tension-releasing “symphonic finale.”
Wishing you the best of health,
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Dr. Andrew Siegel is a physician and urological surgeon who is board-certified in urology as well as in female pelvic medicine and reconstructive surgery. He is an Assistant Clinical Professor of Surgery at the Rutgers-New Jersey Medical School and is a Castle Connolly Top Doctor New York Metro Area, Inside Jersey Top Doctor and Inside Jersey Top Doctor for Women’s Health. His mission is to “bridge the gap” between the public and the medical community. He is a urologist at New Jersey Urology, one of the largest urology practices in the United States. He is the co-founder of PelvicRx and Private Gym. His latest book is Prostate Cancer 20/20: A Practical Guide to Understanding Management Options for Patients and Their Families.
Video trailer for Prostate Cancer 20/20
Preview of Prostate Cancer 20/20
Andrew Siegel MD Amazon author page
PROSTATE CANCER 20/20 is now available at Audible, iTunes and Amazon as an audiobook read by the author (just over 6 hours).
Dr. Siegel’s other books:
THE KEGEL FIX: Recharging Female Pelvic, Sexual, and Urinary Health
MALE PELVIC FITNESS: Optimizing Sexual and Urinary Health
PROMISCUOUS EATING— Understanding and Ending Our Self-Destructive Relationship with Food
Our Greatest Wealth Is Health 