8 Little Known Facts About the Temple

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The human body is an amazing thing. For each one of us, it’s the most intimate object we know. And yet most of us don’t know enough about it: its features, functions, quirks, and mysteries. Our series The Body explores human anatomy, part by part. Think of it as a mini digital encyclopedia with a dose of wow.

 

At the edges of the eyebrows, you’ll find the temple, the flat, tender side of the head where you often press your fingers to relieve a headache. In movies, one karate chop to this area can allegedly kill a person, but is this really true? What lies beneath that smooth surface of skin that’s so delicate? To learn more, Mental Floss spoke to Dr. Abbas Anwar, an otolaryngologist and head and neck surgeon at Southern California Head and Neck Medical Group in Santa Monica.

1. THE TEMPLE IS A JUNCTURE.

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It's technically where four skull bones—the frontal, parietal, temporal, and sphenoid—meet in the skull. This vulnerable juncture is called the pterion, which means "wing" in Greek but sounds like a kind of dinosaur.

2. IT REVEALS A DISTANT LINK TO REPTILES.

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The temporal bone itself is made up of five smaller parts, which fuse together before birth. One of these pieces, called the tympanic part, may be evolutionarily linked to the angular bone in the lower jaws of reptiles.

3. IT'S THE THINNEST PART OF THE SKULL …

profile of human skull
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While these skull bones are "relatively strong," though thin, Anwar tells Mental Floss, the point at which they meet is the weakest point because there's no solid bone beneath them. "As such, this area is at risk with direct horizontal blows."

4. … WHICH IS WHY MAORI WARRIORS CRAFTED A SPECIAL WEAPON TO CRUSH IT.

maori stone club
Australian Museum, Wikimedia Commons // CC BY-SA 3.0

When Maori warriors of the first nations tribes of New Zealand and Australia went into battle, one weapon they took with them was the patu onewa, a flat, heavy club carved from stones such as basalt, and sometimes jade, for the specific purpose of delivering a fatal, crushing blow to the temple.

5. THE TEMPLE COVERS A MAJOR ARTERY.

historical medical illustration of head and scalp arteries
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Running below these bones is a large artery known as the middle meningeal artery. It supplies blood to the outer covering of the brain, the meninges. "If hit hard enough, one of the four bones at this point can fracture inward and lacerate the middle meningeal artery," Anwar explains. This can cause an epidural hematoma, essentially "a collection of blood that builds up around the brain and compresses it."

Severe bleeding can cause "catastrophic consequences" if not recognized and treated promptly, including brain herniation (bulging brain tissue), hemiparesis (weakness of one side of the body), and death.

6. IS YOUR TEMPLE A SACRED SPACE?

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Etymologists don't entirely agree on the meaning of the word temple, which has multiple origins. It may derive from the Latin word for time, tempus, according to a Dartmouth Medical School anatomy course: "The connection may be that with the passage of time, grey hairs appear here early on. Or it may relate to the pulsations of the underlying superficial temporal artery, marking the time we have left here."

It could also possibly hail from the Greek word temenos, meaning "place cut off," which would explain the idea of a temple of worship as well as that juncture of bones at the side of the head. 

In Old English, tempel meant "any place regarded as occupied by divine presence," which might be code for the brain as the residence of consciousness or God.

More likely it's related to the Greek pterion, which as you'll recall means "wing." In Greek mythology, Hermes, messenger of the gods, wore a helmet with wings, which were positioned over the temples.  

7. IT'S PRONE TO SKIN CANCER THAT'S HARD TO REMOVE.

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Surgeon Gabriel Weston writes in The Guardian that skin cancers frequently turn up in this area from over exposure to the Sun, which makes for a challenging surgical procedure. "It is often not possible simply to sew up the hole in the skin after cutting a cancer out, since doing so can easily distort the contour of the eye," he writes.

To get around the problem, Weston uses a special technique called a Wolfe graft. After cutting away the cancerous lesion, "I measure out a circle of equal size in the skin above the collar-bone (where the skin is similar) and remove it." He grafts this skin patch to the patient's temple "with tiny silk sutures." 

8. BRAIN FREEZE ISN'T IN YOUR BRAIN.

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Sometimes when you eat or drink something cold too quickly, you get brain freeze, which can feel like someone has taken knives to your temples. But the pain isn't actually in your brain at all, as brains have no pain receptors. While researchers haven't been able to determine a cause of what's technically called sphenopalatine ganglioneuralgia, or sometimes HICS ("headache attributed to ingestion or inhalation of a cold stimulus"), they theorize that the painful freeze you experience is likely caused by a quick cooling of the blood in the back of your throat at the juncture your internal carotid and anterior cerebral arteries, which can cause spasms or constrictions of the arterial branches.

7 Facts About Blood

Moussa81/iStock via Getty Images
Moussa81/iStock via Getty Images

Everyone knows that when you get cut, you bleed—a result of the constant movement of blood through our bodies. But do you know all of the functions the circulatory system actually performs? Here are some surprising facts about human blood—and a few cringe-worthy theories that preceded the modern scientific understanding of this vital fluid.

1. Doctors still use bloodletting and leeches to treat diseases.

Ancient peoples knew the circulatory system was important to overall health. That may be one reason for bloodletting, the practice of cutting people to “cure” everything from cancer to infections to mental illness. For the better part of two millennia, it persisted as one of the most common medical procedures.

Hippocrates believed that illness was caused by an imbalance of four “humors”—blood, phlegm, black bile, and yellow bile. For centuries, doctors believed balance could be restored by removing excess blood, often by bloodletting or leeches. It didn’t always go so well. George Washington, for example, died soon after his physician treated a sore throat with bloodletting and a series of other agonizing procedures.

By the mid-19th century, bloodletting was on its way out, but it hasn’t completely disappeared. Bloodletting is an effective treatment for some rare conditions like hemochromatosis, a hereditary condition causing your body to absorb too much iron.

Leeches have also made a comeback in medicine. We now know that leech saliva contains substances with anti-inflammatory, antibiotic, and anesthetic properties. It also contains hirudin, an enzyme that prevents clotting. It lets more oxygenated blood into the wound, reducing swelling and helping to rebuild tiny blood vessels so that it can heal faster. That’s why leeches are still sometimes used in treating certain circulatory diseases, arthritis, and skin grafting, and helps reattach fingers and toes. (Contrary to popular belief, even the blood-sucking variety of leech is not all that interested in human blood.)

2. Scientists didn't understand how blood circulation worked until the 17th century.

William Harvey, an English physician, is generally credited with discovering and demonstrating the mechanics of circulation, though his work developed out of the cumulative body of research on the subject over centuries.

The prevailing theory in Harvey’s time was that the lungs, not the heart, moved blood through the body. In part by dissecting living animals and studying their still-beating hearts, Harvey was able to describe how the heart pumped blood through the body and how blood returned to the heart. He also showed how valves in veins helped control the flow of blood through the body. Harvey was ridiculed by many of his contemporaries, but his theories were ultimately vindicated.

3. Blood types were discovered in the early 20th century.

Austrian physician Karl Landsteiner discovered different blood groups in 1901, after he noticed that blood mixed from people with different types would clot. His subsequent research classified types A, B and O. (Later research identified an additional type, AB). Blood types are differentiated by the kinds of antigens—molecules that provoke an immune system reaction—that attach to red blood cells.

People with Type A blood have only A antigens attached to their red cells but have B antigens in their plasma. In those with Type B blood, the location of the antigens is reversed. Type O blood has neither A nor B antigens on red cells, but both are present in the plasma. And finally, Type AB has both A and B antigens on red cells but neither in plasma. But wait, there’s more! When a third antigen, called the Rh factor, is present, the blood type is classified as positive. When Rh factor is absent, the blood type is negative.

Scientists still don’t understand why humans have different blood types, but knowing yours is important: Some people have life-threatening reactions if they receive a blood type during a transfusion that doesn’t “mix” with their own. Before researchers developed reliable ways to detect blood types, that tended to turn out badly for people receiving an incompatible human (or animal!) blood transfusion.

4. Blood makes up about 8 percent of our total body weight.

Adult bodies contain about 5 liters (5.3 quarts) of blood. An exception is pregnant women, whose bodies can produce about 50 percent more blood to nourish a fetus.)

Plasma, the liquid portion of blood, accounts for about 3 liters. It carries red and white blood cells and platelets, which deliver oxygen to our cells, fight disease, and repair damaged vessels. These cells are joined by electrolytes, antibodies, vitamins, proteins, and other nutrients required to maintain all the other cells in the body.

5. A healthy red blood cell lasts for roughly 120 days.

Red blood cells contain an important protein called hemoglobin that delivers oxygen to all the other cells in our bodies. It also carries carbon dioxide from those cells back to the lungs.

Red blood cells are produced in bone marrow, but not everyone produces healthy ones. People with sickle cell anemia, a hereditary condition, develop malformed red blood cells that get stuck in blood vessels. These blood cells last about 10 to 20 days, which leads to a chronic shortage of red blood cells, often causing to pain, infection, and organ damage.

6. Blood might play a role in treating Alzheimer's disease.

In 2014, research led by Stanford University scientists found that injecting the plasma of young mice into older mice improved memory and learning. Their findings follow years of experiments in which scientists surgically joined the circulatory systems of old and young mice to test whether young blood could reverse signs of aging. Those results showed rejuvenating effects of a particular blood protein on the organs of older mice.

The Stanford team’s findings that young blood had positive effects on mouse memory and learning sparked intense interest in whether it could eventually lead to new treatments for Alzheimer’s disease and other age-related conditions.

7. The sight of blood can make people faint.

For 3 to 4 percent of people, squeamishness associated with blood, injury, or invasive medical procedures like injections rises to the level of a true phobia called blood injury injection phobia (BII). And most sufferers share a common reaction: fainting.

Most phobias cause an increase in heart rate and blood pressure, and often muscle tension, shakes, and sweating: part of the body’s sympathetic nervous system’s “fight or flight” response. But sufferers of BII experience an added symptom. After initially increasing, their blood pressure and heart rate will abruptly drop.

This reaction is caused by the vagus nerve, which works to keep a steady heart rate, among other things. But the vagus nerve sometimes overdoes it, pushing blood pressure and heart rate too low. (You may have experienced this phenomenon if you’ve ever felt faint while hungry, dehydrated, startled, or standing up too fast.) For people with BII, the vasovagal response can happen at the mere sight or suggestion of blood, needles, or bodily injury, making even a routine medical or dental checkup cause for dread and embarrassment.

What Purpose Does the Belly Button Serve?

misuma/iStock via Getty Images
misuma/iStock via Getty Images

While your eyelashes are protecting your eyes, your lungs are letting you breathe, and virtually every other part of your body—inside and out—is performing its own relatively well-known task, your belly button is just sitting there collecting lint. And while it’s true that your navel served its most important purpose before you were born, it’s not totally useless now.

According to ZME Science, back when you were a fetus, your belly button was more of a belly portal: Your umbilical cord extended from it and connected you to the placenta on your mother’s uterine wall. That way, the placenta could channel nutrients and oxygen to you through the cord, and you could send back waste.

Your umbilical cord was cut when you were born, creating a tiny bulge that left behind some scar tissue after it healed. That scar tissue is your belly button, navel, or umbilicus. Though you may have heard that the shape of your belly button is a direct result of the scissor skills of the doctor who delivered you, that’s not true. Dr. Dan Polk, a neonatologist in the Chicago area, told the Chicago Tribune that a belly button's shape “has to do with how much baby skin leads onto the umbilical cord from the baby’s body. Less skin makes an innie; more skin makes an outie.” About 90 percent of people have innies.

Regardless of how your belly button looks, you probably don’t use it on a daily basis. However, if you’ve studied anatomy, medicine, or a related field, you might recognize it as the central point by which the abdomen is divided into the following quadrants: right upper, left upper, right lower, and left lower. Another way of classifying that area is into nine regions—including the hypochondriac, lumbar, iliac, epigastric, and hypogastric regions—with the umbilical region at the very center.

Abdominopelvic regions diagram
Blausen Medical, Wikimedia Commons // CC BY 3.0

Your belly button can also serve as the opening for laparoscopic surgery, which can save you from having a scar elsewhere on your abdomen.

The navel is a great central landmark outside of medicine, too. If you’ve taken yoga or Pilates classes, you may have heard it referred to as the center of balance or center of gravity. Because it sits right on top of your abdominal muscles, your belly button is an easy marker for your instructor to mention when they want you to access your core, which helps you balance.

And, of course, belly buttons are notorious for storing quite a bit of lint, which always seems to be blue (you can learn more about that here).

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

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