Mechanisms of Penis Erection: Understanding Blood Flow Dynamics and Rigidity
A normal erection is characterized by the rigidity (hardness) of the penis and an increase in its size. This requires blood filling of the penile cavernous bodies—the more blood they receive, the firmer and larger the penis becomes. It is well known that blood enters any organ through arteries and exits through veins. The penis is no exception. At rest, the inflow of blood through the arteries is equal to the outflow of blood through the veins, but for an erection to occur, the inflow of blood must be significantly greater than the outflow. Let's examine the mechanism of penile erection:
- The brain sends a command to the penile cavernous bodies through nerves.
- As a result of this command, nitric oxide is released, and the smooth muscles of the cavernous bodies relax.
- Consequently, the walls of the cavernous bodies become more elastic, and they receive more blood through the arteries—the penis begins to increase in size. This process is called tumescence.
- At this stage, a lot of blood enters the penis, but part of it flows back through the veins, so the rigidity (hardness) of the penis is insufficient. If at this moment an ultrasound of the penile arteries is performed with the determination of blood flow speed, the speed will be 35 – 40 cm/sec (at rest 8 – 10 cm/sec).
- The penis gradually increases in diameter, and the veins located around the cavernous bodies are compressed between the cavernous bodies and the tunica albuginea, meaning the outflow of blood through them is significantly reduced.
- The inflow of blood through the arteries remains at a high level, so the penis quickly increases in size and becomes firm.
- The penile cavernous bodies are maximally filled with blood; they can no longer stretch, so the inflow of blood decreases, and the outflow practically stops. This is the stage of rigid erection, and intercourse can be fully performed!
However, often during sexual activity, blood gradually "leaves" the penis—resulting in an unstable erection that can disappear at the "most crucial moment"! This is referred to as arteriogenic erectile dysfunction.
There are several medical articles indicating that often the cause of erectile dysfunction is:
- Chronic masturbation (wow! There is a way out to avoid its adverse effects if done correctly - more on this can be read here)
- Penis stretching
- Vacuum pump
What kind of trouble is this, and how can it be avoided? According to modern understanding, erectile dysfunction is mainly associated with the condition of a man's pelvic floor muscles. Let's take a closer look at these muscles.
Typically, the front part of the male pelvic floor consists of two very important muscles:
- BC - bulbospongiosus - the bulbocavernosus muscle, also known as the orgasmic muscle (it is contracted during the direct Kegel exercise)
- IC - ischiocavernosus - the ischiocavernosus muscle, also known as the erectile muscle
- The bulbospongiosus muscle, m. bulbospongiosus, surrounds the bulb and the posterior part of the spongy body—starting from the perineal central tendon and attaching to the dorsal surface of the cavernous bodies and the fascia of the penis itself; as a result of the muscle's contraction, the outflow of venous blood from the cavernous bodies during erection is hindered, sperm is expelled from the urethra during orgasm, and the last drops of urine are squeezed out during urination;
- The ischiocavernosus muscle, m. ischiocavernosus, is a paired muscle—starting from behind the root of the cavernous body and the sacrotuberous ligament; its tendon weaves into the tunica albuginea of the cavernous body; upon contraction, the muscle presses the root of the cavernous body against the bone, straightens the penis, and clamps its dorsal veins.
Locating the ICM on an erect penis for training
Anatomy details:
"The male penis consists of 20-25% tendons of striated muscles, which are more abundant in the tunica albuginea. The tunica albuginea of the penis root consists of 8-10, and in the body - of 4-6 dense layers of tendinous bundles, the thickness of which decreases by 1.5 times in the distal direction. The tendinous bundles, transitioning from layer to layer, from the dorsal side of the male penis to the urethral surface, with dense loops, encircling and permeating all the cavernous tissue, form a single tendinous skeleton of the organ, more pronounced in men of the muscular somatotype, and less so in the thoracic type. The tendinous bundles of all sections of the male penis consist of collagen (64.5±0.9%) and elastic (8.2±0.3%) fibers, fibroblasts (4.2±0.2%), and the matrix (23.1±0.9%)."
On an erect penis, the ICM can be easily detected when it contracts at the base of the penis near the pubis and along the sides of the hidden part of the penis in the perineum (the two legs of the muscle run along both sides of the hidden part of the penis all the way to the anus).