Your body is a highly complicated machine with numerous unseen components behind it. Of all the most fascinating groups of muscles in your body, sphincters are probably the most fascinating ones. Sphincters are very small round muscles that function as valves that open and close to govern the passage of food, fluid, blood, and even trash. The mundane process of living would be almost impossible without them.
How many sphincters are in the human body, then? This has puzzled scientists, doctors, and even the public at large because the answer is less obvious than one or two. There are tens of sphincters in the body, some of which individuals are familiar with, and some they are not. This article will list their number, where they are found, and why they are so vital to living.
What Is a Sphincter?
A sphincter is a ring-shaped muscle encircling an opening or a passage in the body. It closes the passage when it tightens and opens when it relaxes. One may liken it to a body valve or a door.
Sphincters are either voluntary or involuntary. Voluntary sphincters you control consciously. Such as when you decide to retain urine or stool from exiting. Involuntary sphincters work automatically without your awareness. Such as muscles that block stomach acid from moving up into your throat.
How Many Sphincters Are in the Human Body?
There are more than sixty sphincters in the human body. Some scientists count slightly lower or slightly higher based on categorization, but they all agree that the body possesses dozens of them. They can be found in a variety of systems. Like the digestive system, urinary system, circulatory system, and reproductive system.
The largest sphincters that are most commonly known are the ones in the digestive system. It includes the lower esophageal sphincter, the pyloric sphincter, and the anal sphincter. Blood vessels, eyes, and even small body structures all have sphincters as well.
Break the largest sphincters down by system.
Digestive System Sphincters
The digestive system contains the largest sphincters. They regulate food and waste passing through your body.
Upper Esophageal Sphincter
It is present at the uppermost region of the esophagus and controls swallowing and also prevents further air from entering into the digestive system.
Lower Esophageal Sphincter
It is present at the end of the esophagus and prevents acid in the stomach from flowing back into the esophagus and protects you from acid reflux.
Pyloric Sphincter
Sphincter is between the stomach and small intestine. It controls excess food entry into the small intestine for digestion.
Sphincter of Oddi
At the junction site of the small intestine and bile duct, it controls the entrance of bile and pancreatic juice into the intestine.
Ileocecal Sphincter
At the junction site of small intestine and large intestine, it controls one-way movement of food and against backflow.
Internal Anal Sphincter
An involuntary muscle which keeps stool inside the body.
External Anal Sphincter
A voluntary muscle which places you under voluntary control for bowel movement.
These are the most widespread digestive sphincters, though there are minute ones in glands and ducts too.
Urinary System Sphincters
Sphincters serve a vital purpose in urinating.
Internal Urethral Sphincter
An involuntary muscle that serves to not let urine leak from the bladder.
External Urethral Sphincter
A voluntary muscle that gives you voluntary control over when to urinate.
These two sphincters assist your urinary system to work properly.
Sphincters of the Circulatory System
Your blood vessels also have sphincters, only smaller and less well known.
Precapillary Sphincters
Small muscles regulate blood into capillaries so the tissue can absorb an adequate amount of oxygen and nutrients.
Cardiac Sphincters
Even though not always separated into a category, the heart does have valve-like sphincters that open to allow blood through.
The blood wouldn’t reach the different parts of the body if not for these small sphincters.
Sphincters of the Reproductive System
The reproductive process also relies on sphincters.
Sphincter at Neck of Bladder in Male
Prevents the semen from returning backward to the bladder during the time to ejaculate.
Female Vaginal and Uterine Sphincters
Helps during childbirth, and menstrual regulation.
These muscles, although less spoken of, are extremely vital to reproductive well-being.
Other Sphincters within the Body
There are small ones, and of course, the famous ones.
Pupil Sphincter (Iris Sphincter)
Regulates the diameter of your pupil, when light enters.
Laryngeal Sphincters
Assist in voice control and protection of the airway during swallowing.
Bile Duct Sphincters
Regulate the entry of bile into the intestine.
There are over 60 sphincters in the body if small sphincters are included.
Why are Sphincters Important?
Sphincters are important because:
- They assist in digestion: They transport food in one direction.
- Continence: Prevents unwanted leakage of urine or stool from happening.
- Blood circulation: They control blood flow to various tissues.
- Protection: They guard against harmful backflow such as gastric acid reflux.
- Reproduction: They aid in childbirth, ejaculation, and menstruation.
- Vision and communication: Eye and throat sphincters enable vision and voice.
If one did not have sphincters, one would not survive.
Common Sphincter Issues
As sphincters are muscles, they may relax or lose function. Some of the common issues are:
- Acid Reflux (GERD) due to weakening of lower esophageal sphincter.
- Urinary Incontinence when urine sphincters are unable to hold urine.
- Fecal Incontinence when anus sphincters are unable to hold the bowel movements.
- Pupil Disorders when eye sphincters fail, they create vision disorders.
- Spasms or Strictures sphincters tend to spasm too forcefully and plug flow.
Therapy, drug, or surgery cure these diseases based on severity.
How to Keep Sphincters Healthy
You can strengthen and guard sphincters with some modifications in lifestyle.
- Have a healthy diet with a lot of fiber to prevent constipation.
- Exercise regularly for muscle strength maintenance.
- Take adequate fluid intake to aid smooth passage and digestion.
- Avoid smoking and other alcohol, both for weakening sphincters.
- Aim to be of normal weight to minimize stress on urinary and digestive sphincters.
- Practice pelvic floor exercises such as Kegels to build up urinary and anal sphincters.
- Visit a doctor in case of leakage, pain, or other discomfort experienced.
Cost of Sphincter-Related Treatment
Sphincter treatment by a doctor is uncertain.
- Medication to manage incontinence or reflux: $20 to $100 monthly.
- Physical therapy of pelvic floor: $50 to $150 per visit.
- Surgical sphincter repair: $3,000 to $10,000 depending on severity and location.
- Diagnostic tests such as endoscopy or urodynamic studies: $500 to $2,000.
Treatments are usually covered by insurance. But it varies depending on the plan.
FAQs
Are there many sphincters in the body?
There are more than 60 in all.
What is the largest sphincter?
The anal sphincters are biggest and strongest.
Are sphincters voluntary?
Some are the external anal sphincter, but others are automatic.
Do sphincters get weaker with age?
Yes, by disease and age they can weaken.
Do exercises strengthen sphincters?
Yes, Kegel exercises and core training make them not weak.
Sphincters are tiny. But they are some of the most important muscles in the human body. Sphincters are technically the body’s natural doors. It regulates the flow of food, fluid, blood, and waste. There are more than 60 sphincters within the body, each performing a unique function so that life can continue effortlessly.
From swallowing your meals to holding back your stool, from protecting your windpipe to guiding your eyes, sphincters work unobtrusively on your behalf second after second of the day. When they go wrong, grave disease ensues, but the comforting fact is that most of them are preventable or treatable by good habits and physician’s attention.
So the next time you think of the amazing things your body can do, remember to spare a thought to consider and thank the humble sphincters holding everything together in lovely harmony.
