Skip to content


Mechanisms of Penis Erection: Understanding Blood Flow Dynamics and Rigidity

by NPE Blog 01 Apr 2024 0 Comments

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:

  1. The brain sends a command to the penile cavernous bodies through nerves.
  2. As a result of this command, nitric oxide is released, and the smooth muscles of the cavernous bodies relax.
  3. 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.
  4. 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).
  5. 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.
  6. The inflow of blood through the arteries remains at a high level, so the penis quickly increases in size and becomes firm.
  7. 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).


Important Information

The contraction of the ischiocavernosus muscle (IC) compresses the legs of the penis, propelling blood from their roots to the distal parts.

The surrounding veins that drain the penis are also compressed by the ischiocavernosus action, limiting venous outflow. This increased volume of venous blood supports the stretching of the penis, helping to maintain an erection during sexual arousal and intercourse. In men, the ischiocavernosus muscle also acts together to stabilize the penis in a fully erect state. Thus, the erection of the penis upon arousal is primarily due to the contraction of the ischiocavernosus muscle (IC), which restricts the venous outflow of blood from the penis, along with the contraction of the venous outflow due to the compression of veins that are located around the cavernous bodies, by the tunica albuginea.

Both muscles are a kind of antagonists. It is nearly impossible to fully tense the BC and IC muscles simultaneously. We train the BC muscle a lot during penis enlargement exercises. For many, this muscle is overtrained, leading to an imbalance compared to the IC.

As noted above, years of masturbation significantly strengthen our orgasmic muscle and weaken our erecting one.

During sex, when the head of the penis is compressed from contact with the walls of the vagina, it creates a reflex that helps activate the ischiocavernosus muscle, thereby providing a firm erection of the penis.

As you may have noticed, this does not exist with masturbation. That is why prolonged masturbation can lead to a phenomenon known as PIED (porn-induced erectile dysfunction). When you jelq or stretch your penis, you are primarily pulling this muscle - the ischiocavernosus muscle.

When you stretch the muscle externally, a myotatic reflex is activated, pulling the muscle back. That's why it's noted that penis stretching during enlargement exercises strains and, in the long term, weakens this muscle.

From the information provided, conclusions can already be drawn on how to masturbate correctly and how one can start simple training of the IC muscle.

You can read the article "HOW TO MASTURBATE CORRECTLY" here.

Prev Post
Next Post

Leave a comment

Please note, comments need to be approved before they are published.

Someone recently bought a
[time] ago, from [location]

Thanks for subscribing!

This email has been registered!

Shop the look

Choose Options

Recently Viewed

Edit Option
Back In Stock Notification
Terms & Conditions


Harassment in any manner or form on the site, including via e-mail, chat, or by use of obscene or abusive language, is strictly forbidden. Impersonation of others, including a or other licensed employee, host, or representative, as well as other members or visitors on the site is prohibited. You may not upload to, distribute, or otherwise publish through the site any content which is libelous, defamatory, obscene, threatening, invasive of privacy or publicity rights, abusive, illegal, or otherwise objectionable which may constitute or encourage a criminal offense, violate the rights of any party or which may otherwise give rise to liability or violate any law. You may not upload commercial content on the site or use the site to solicit others to join or become members of any other commercial online service or other organization.


All brand names and products mentioned herein are either registered trademarks or trademarks of their respective owners and are hereby recognized as such.


We do not accept returns or exchanges, since according to the laws on the sale of virtual products, such as in this case, “instructions for enlarging the penis using physical exercises” are not subject to returns or exchanges.


In the event of a price reduction, does not refund the difference for an intellectual product previously purchased by the buyer.


You agree to indemnify, defend, and hold harmless, its officers, directors, employees, agents, licensors and suppliers (collectively the "Service Providers") from and against all losses, expenses, damages and costs, including reasonable attorneys' fees, resulting from any violation of these terms and conditions or any activity related to your account (including negligent or wrongful conduct) by you or any other person accessing the site using your Internet account.


These terms and conditions are applicable to you upon your accessing the site and/or completing the registration or shopping process. These terms and conditions, or any part of them, may be terminated by without notice at any time, for any reason. The provisions relating to Copyrights, Trademark, Disclaimer, Limitation of Liability, Indemnification and Miscellaneous, shall survive any termination.

NOTICE may deliver notice to you by means of e-mail, a general notice on the site, or by other reliable method to the address you have provided to

PARTICIPATION DISCLAIMER does not and cannot review all communications and materials posted to or created by users accessing the site, and are not in any manner responsible for the content of these communications and materials. You acknowledge that by providing you with the ability to view and distribute user-generated content on the site, is merely acting as a passive conduit for such distribution and is not undertaking any obligation or liability relating to any contents or activities on the site. However, reserves the right to block or remove communications or materials that it determines to be (a) abusive, defamatory, or obscene, (b) fraudulent, deceptive, or misleading, (c) in violation of a copyright, trademark or; other intellectual property right of another or (d) offensive or otherwise unacceptable to in its sole discretion.

LIMITATION OF LIABILITY shall not be liable for any special or consequential damages that result from the use of, or the inability to use, the materials on this site or the performance of the products, even if has been advised of the possibility of such damages. Applicable law may not allow the limitation of exclusion of liability or incidental or consequential damages, so the above limitation or exclusion may not apply to you.


We do not accept returns or exchanges, since according to the laws on the sale of virtual products, such as in this case, “instructions for enlarging the penis using physical exercises” are not subject to returns or exchanges.


These terms and conditions, together with an invoice regarding the products ordered by the Customer, are the complete and exclusive agreement between and Customer, and they supersede all prior or contemporaneous proposals, oral or written, understandings, representations, conditions, warranties, and all other communications between and Customer relating to the subject products. This agreement may not be explained or supplemented by any prior course of dealings or trade by custom or usage.


We guarantee that every online transaction you make will be 100% safe. Under the Fair Credit Billing Act, your bank cannot hold you liable for more than $50.00 for fraudulent charges. If your bank does hold you liable for $50.00, will cover the entire liability for you, up to the full $50.00. will only cover this liability if the unauthorized use of your credit card resulted through no fault of your own from purchases made while using our secure server. In the event of unauthorized use of your credit card, you must notify your credit card provider in accordance with its reporting rules and procedures.

PRIVACY respects and values your privacy. We will not under any circumstances sell or release your information to anyone except as outlined in our privacy policy. All of the information obtained from our website will be used for processing purposes only. The only e-mails you will receive from are:
  • Transactional: updates to status of orders and returns
  • Promotional: updates about discounts, new products, etc.
  • Informational: updates about
this is just a warning