A reflex is an automatic response to a stimulus, an action that occurs without conscious thought. Many of us are familiar with the knee jerk reflex, in which the knee straightens as a result of the quadriceps muscle contracting in response to the tendon of our kneecap being tapped with a reflex hammer.
Here are six reflexes that you probably aren’t aware of, but are vital to your urinary and sexual health:
- Guarding Reflex. The sphincter muscles guard the entrance to the urinary bladder. The voluntary sphincter muscle—the one that you have control of and are capable of contracting at will—is largely composed of the deep pelvic floor muscles (PFMs). The deep PFMs are your friends, helping you store urine while the bladder fills up. Even when you are not actively squeezing the PFMs, they have a baseline tone, working to provide resistance that keeps you from leaking urine as the bladder becomes fuller. They only relax completely when you urinate. The guarding reflex is the increase in the contraction strength of these “guarding” PFMs as the bladder gets fuller and fuller, with stronger PFM tone as the volume of urine in the urinary bladder increases.
- Cough Reflex. This reflex increases the contraction of the PFMs when you cough—above and beyond their resting tone—preventing you from leaking urine. This is nature’s way of protecting you from leaking urine when there is a sudden increase in your abdominal pressure, as occurs with a cough. This protects against cough-related stress urinary incontinence.
- Pelvic Floor Muscle-Bladder Reflex (PFM-BR). The PFM-BR is a unique reflex that you are capable of engaging voluntarily, resulting in the relaxation of a muscle as opposed to its contraction. Anyone who has ever experienced an urgent desire to urinate or move their bowels will find it of great practical use. When the reflex is deployed, it will result in relaxation of both the urinary bladder and rectum and a quieting of the urgency. It works when you feel the sudden and urgent desire to urinate—pulse the pelvic floor muscles (PFMs) five times—brief but intense contractions. When the PFMs are so deployed, the bladder muscle reflexively relaxes and the feeling of intense urgency disappears. Likewise, when the PFMs are deployed, the rectum relaxes and the feeling of intense bowel urgency should diminish. This reflex is a keeper when you are stuck in traffic and have no access to a toilet!
- BulboCavernosus Reflex (BCR). The BCR is a contraction of the bulbocavernosus and its mates, the ischiocavernosus (IC) muscles when the glans (head) of the penis in a male or the clitoris in a female is squeezed. This reflex is important for maintaining erectile rigidity, since with each contraction of the BC and IC muscles there is a surge of blood flow to the penis/clitoris, maintaining the high blood pressures within the erectile chambers necessary for engorgement of these organs. Sexual stimulation can be thought of as a chain of linked BCRs.
- Double reflex. Did you ever experience an urgent desire to urinate and find relief by squeezing the head of the penis? If so, you have discovered the linkage of two reflexes—the BCR coupled with the PF-MBR. Here’s what happens: A strong urge to urinate occurs and is managed by squeezing the head of the penis, which makes the urgency dissipate. What’s actually happening is that the squeeze of the penis triggers a PFM contraction via the BCR. In turn, the PFM contraction relaxes the bladder muscle via the PFM-BR and makes the urgency either improve or disappear. Reflex magic!
- Cremasteric reflex. The cremaster muscle surrounds the spermatic cord (the cord-like structure that contains the testicular blood supply, nerves, etc.). The cremasteric reflex occurs when the inner thigh is stroked and the testicle pulls up towards the groin via a contraction of the cremaster muscle. This is a brisk reflex in boys and tends to become less active with aging. It is a natural protective reflex that helps us avoid testicular injury when danger approaches, like a turtle pulling its head into its protective shell.
The reflexes described above are vital to your sexual and urinary health. Being aware of them, and knowing how to tap into them can be used to your advantage!