Touch your cheek or arm. You're able to feel this sensation because of Pacinian corpuscles (which are one of the main types of nerve endings in the skin). These receptors recognize deep pressure and pain.
But the foreskin has a different type of nerve receptor. The ridged band is a ring of highly innervated tissue just inside the tip of the foreskin. In this ridged band are Meissner's corpuscles, which recognize light touch and heat. In particular, they have the highest sensitivity (lowest threshold) when sensing vibrations lower than 50 Hertz.
To feel the difference between Pacinian corpuscles and Meissner's corpuscles:
Gently run your fingers over the back of your hand. Now, turn your hand over and gently run your fingers over the palm of your hand. Feel the difference?
This is because the palm of your hand has Meissner's corpuscles, just like the foreskin and frenulum. They are what make our fingers and palms so sensitive, as well as our lips, anus, and other opening of the body.
Penis Mechanoreception - How Your Penis Actually "Feels" the Vagina
Dr. von Neumann, who co-authored a manual on helping men get the most out of their Sexual Potential, writes: "[Meissner's corpuscles] are tactile sensors in the surface of the skin. They are what we use at the end of our fingers to detect very fine "touch" sensations. They are responsive to light touch and vibration. In the penis, they are located only in the foreskin and frenulum. These type of receptors allow the penis (through the foreskin) to "feel" its way in the vagina.
Men who are circumcised have, unfortunately, lost this ability of very fine penile sensation. The foreskin is the only region of the penis that has Meissner's Corpuscles apart from the frenulum and its bands. This is the tear-dropped formation just below the glans of the penis as it attaches to the shaft. [...] Unfortunately for men who have been circumcised and have lost their foreskin, they will be unable to appreciate the fine, tactile feel of the inside of a woman's vagina. There may be some leftover Meissner's Corpuscles in the frenulum if it wasn't damaged too badly during the circumcision."
This is why circumcised men will say that the most sensitive part of their penis is the small part of the frenulum that remains, if any. See diagram below:
Morris L. Sorrells, James L. Snyder, Mark D. Reiss, Christopher Eden*, Marilyn F. Milos†, Norma Wilcox and Robert S. Van Howe‡ Retired, *HIV/AIDS researcher, San Francisco, CA, †National Organization of Circumcision Information Resource Centers,
‡Department of Paediatrics and Human Development, Michigan State University College of Human Medicine, MI, USA
Accepted for publication 22 October 2006
To map the fine-touch pressure thresholds of the adult penis in circumcised and
uncircumcised men, and to compare the two populations.
SUBJECTS AND METHODS
Adult male volunteers with no history of penile pathology or diabetes were evaluated
with a Semmes-Weinstein monofilament touch-test to map the fine-touch pressure
thresholds of the penis. Circumcised and uncircumcised men were compared using
mixed models for repeated data, controlling for age, type of underwear worn, time since last ejaculation, ethnicity, country of birth, and level of education.
The glans of the uncircumcised men had significantly lower mean (SEM) pressure
thresholds than that of the circumcised men, at 0.161 (0.078) g (P=0.040) when controlled for age, location of measurement, type of underwear worn, and ethnicity. There were significant differences in pressure thresholds by location on the penis
(P<0.001). The most sensitive location on the circumcised penis was the circumcision scar on the ventral surface. Five locations on the uncircumcised penis that are routinely removed at circumcision had lower pressure thresholds than the ventral scar of the circumcised penis.
The glans of the circumcised penis is less sensitive to fine touch than the glans of the uncircumcised penis. The transitional region from the external to the internal prepuce is the most sensitive region of the uncircumcised penis and more sensitive than the most sensitive region of the circumcised penis. Circumcision ablates the most sensitive parts of the penis.
Fine-touch pressure thresholds in the adult penis:
The Ridged Band of the Human Prepuce:
Penis Mechanoreception - How Your Penis Actually "Feels" the Vagina:
Medical Studies on Circumcision: