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Hip, Hip, Hooray: Understanding Hip Osteoarthritis and Hip Replacements

Posted by Madison Oppenheim on Thu, Sep 15, 2016 @ 07:40 AM

Today's blog post is brought to you in part by the saying "you don't know what you have until it's gone."

Your hip is an essential joint that I'm sure you don't put much thought into during the day while you bend down to tie your shoe or get out of your chair for your three o'clock bathroom break. But neither of those activities would be possible without it. 

  

Do the Hula: Anatomy of The Hip

The hula hoop is a classic childhood activity seconded only by the limbo. When doing hula, you shake and shimmy until you drop the hoop and/or beat your competitor (I always made everything into a competition). Your hip enables you to shake your way to victory and beat Ashley, who is weak

Your hip is a ball-and-socket joint that gives you mobility in all directions: forward, backward, left, and right, as well as some rotation. It’s comprised of the pelvis and femoral head (upper part of femur). The femur articulates at a concave surface formed by the hip bones, called the acetabulum. 

IMG_5751.png

The proximal head of the femur and acetabulum's surface is covered by articular cartilage that decreases friction and protects the bones.
 

OsteNOarthritis!

As we get older, things start going south.

Osteoarthritis is something you’ve probably heard about, thrown around in conversations with your aunt, and unfortunately with age, it can be like a dark cloud, looming over your head and following you everywhere—even to your trip to the store for Q-tips. 

Osteoarthritis is sometimes referred to as "degenerative joint disease" because the cartilage on the surface of joints is worn away with wear-and-tear. This can cause pain and stiffness, and can make it difficult to complete daily tasks (e.g., the bathroom break mentioned above).

IMG_5749.png

It’s a degenerative type of arthritis that usually occurs in people over age 50, but it may pop up in younger people, too. The cartilage in the joint wears away over time and becomes frayed and rough, exposing bone surfaces beneath, which causes the pain. 

Other symptoms include tenderness, stiffness, and pain (obviously). 

There are many risk factors that can cause osteoarthritis besides age, including a family history of osteoarthritis, a hip joint injury, obesity, and developmental dysplasia of the hip (improper hip joint formation at birth).

Although there’s no cure for osteoarthritis, there are some possible treatments for the pain and to improve your mobility. 

Lifestyle changes are an option that can protect your hip joint and slow the osteoarthritis process down. These include minimizing activities that will make it worse (take the elevator instead of the stairs), switching from high-impact to low-impact activities (from running to swimming), and losing weight, which reduces stress on the joint. 

Physical therapy can help improve range of motion and flexibility, as well as strengthen muscles in the hip and leg. 

There are also assistive devices like canes, crutches, and walkers that can improve mobility and can make you feel more independent. Long-handled reachers can help you pick up low things so you don't have to bend over and experience pain. 

There are also a variety of medications to treat pain: acetaminophen (over-the-counter pain reliever you can grab at your local drugstore), nonsteroidal anti-inflammatory drugs, which relieve pain and reduce inflammation, and corticosteroids, which are powerful anti-inflammatory drugs that can be taken orally or injected into the joint. 

 

Hip Op: Surgical Treatments

Hip hop, jazz, EDM, take your pick. After your pain is relieved you’ll want to get up and dance! 

If your doctor recommends surgery to treat your hip osteoarthritis, there are a few options.

An osteotomy is where either the femoral head or the socket is cut and realigned—this takes pressure off of the hip joint.

There’s also hip resurfacing, where the damaged bone and cartilage in the acetabulum are removed and a metal shell is placed instead. The femoral head is capped with a smooth metal covering to reduce friction.

The last option is a total hip replacement. Both the damaged acetabulum and the femoral head are removed and replaced with either metal, plastic, or ceramic joint surfaces to restore the hip's function. So basically you can become bionic (if you choose metal, talk to your doctor about your options). 

 

IMG_5752.png

 



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Source: "Osteoarthritis of the Hip." OrthoInfo. Web. 21 Jul 2016. 

Topics: 3D skeletal system

Chew on This: A Look at the Temporomandibular Joint and TMD

Posted by Madison Oppenheim on Fri, Sep 09, 2016 @ 09:11 AM

Now, I love singing along to the newest Taylor Swift song alone in the car as much as the next gal, but this essential part of my drive to work wouldn't be possible without today's unsung hero: the temporomandibular joint (TMJ). 

The TMJ gets a bad rap because most people associate it with its disorder, which is so unfair. The TMJ and its accomplices are fundamental in allowing jaw movement. Sing along with Swift? TMJ. Open your mouth to let out a bone-crackingly good yawn? TMJ. Yell at characters in horror movies who are stupid enough to open the door? TMJ. 

 

The temporomandibular joint, circledThe TMJ and its partners-in-crime: the stylomandibular ligament and sphenomandibular ligament. 

 

From TMJ to TMD: A Requiem

If you suffer from the pain associated with temporomandibular disorder, or TMD, it may feel like Swift’s "Shake It Off" turns into R.E.M.'s "Everybody Hurts."

The pain is usually concentrated around your jaw and temporomandibular joints, but can also be in and around your ear, as well as your face. You may also have difficulty opening and closing your mouth or chewing.

The TMJ, in mandibular depression


TMD can be caused by a variety of things, including arthritis, dislocation, injury, tooth and jaw alignment, and teeth grinding.

If you have pain or tenderness in your jaw or can't close your jaw completely you should see your doc and get it checked out. 

 

TrEATment: Getting Back to the Butterfingers

I don't know about you, but whenever I hear about issues with my mouth, my first thought is "When can I eat again?" 

With TMD sometimes symptoms go away without treatment, but if not, there are plenty of ways to get you back to your gummy bears, pretzels, apples (since it’s important to touch upon nutrition), and Snickers bars. 

Medications like anti-inflammatories, pain relievers, tricyclic antidepressants, and muscle relaxants can improve your symptoms, and nondrug therapies are also beneficial. 

Mouth guards, physical therapy, and counseling are all options to inform you and help with symptoms. Your doctor may recommend certain procedures if the treatments above aren’t satisfactory, including corticosteroid injections and arthrocentesis (in which fluid is injected into the joint so it can remove debris/inflammation).

There are also a few surgical options available if more conservative approaches don't work. In TMJ arthroscopy, a small cannula is placed into the joint space and has fewer risks than open-joint surgery. With modified condylotomy, the surgery is performed on the mandible and not the joint itself, and is helpful for the treatment of pain. Finally, there’s also open-joint surgery, which may sound frightening, so make sure to speak with your doctor about all the pros and cons. 

 

Now next time "We Are Never Ever Getting Back Together" comes on the radio, you can thank your TMJ for letting you sing along.

 



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Sources:

 "TMJ." American Dental Association. Web. 21 Jul 2016.

"TMJ Disorders". Mayo Clinic. Web. 21 Jul 2016. 

Topics: learn muscle anatomy

In a Pinch: The Anatomy and Pathology of Cervical Radiculopathy

Posted by Madison Oppenheim on Mon, Aug 22, 2016 @ 08:34 AM


No matter how many thousands of dollars you spend on plastic surgery or hours you spend in the gym doing squats, you can't stop the march of time. Everyone is afraid of getting older and the pain that comes with it: arthritis, herniated discs, and pinched nerves, to name a few.

Cervical radiculopathy, commonly known as a pinched nerve, affects 84 out of every 100,000 people per year and occurs when a spinal nerve root in the neck is compressed. 

 

The Back Bone's Connected to the Neck Bone 

The "back bone" is actually a collection of 24 stacked vertebrae that protect your spinal cord from the daily disasters of life. The first 7 vertebrae comprise the cervical spine, a.k.a. your neck. Between each vertebra are intervertebral discs, which are flexible and composed of two parts: the annulus fibrosusthe flexible, tough outer ringand the nucleus pulposusthe soft, pulpy, and highly elastic center. These discs are essential in absorbing shock in everyday movements, like when your friend calls your name from down the hall behind you and your neck snaps around to see who it is, or when "your song" comes on the radio and you bop your head up and down in the car.

Cervical vertebrae and peripheral nerves                    

The spinal cord is like the body's message highwayrelaying information from the brain to the peripheral nerves throughout your body. When your brain tells you to scratch that bug bite on your foot, the message travels down the spinal cord to your arm, which completes the action. 

 

What Is Cervical Radiculopathy?

So we covered the cervical part - relating to your cervical spine, but where does the "radiculopathy" part come from? Radiculopathy is the disease of a nerve root, usually stemming from a pinched nerve. The pain caused by cervical radiculopathy is usually descibed as a burning or sharp pain that begins in the neck and travels down the arm. Other symptoms can include tingling or the feeling of "pins and needles" in the fingers or hand; weakness in the muscles of the arm, shoulder, or hand; and loss of sensation. 

Cervical radiculopathy -- a pinched nerve

A pinched nerve can occur from degenerative changes or an injury to a disc. As I mentioned above, no one is safe from the effects of aging, and as we get older our spine shrinks and can lose water content. This combination leads to a collapse of disc space, which creates bone spurs as the body tries to make up for the lost strength. Bone spurs can cause the foramensmall spaces between vertebrae for nerve roots to leave throughto narrow. These degenerative changes are also known as arthritis or spondylosis. 

We've probably all heard the phrase "Grandpa's got a herniated disc" at one time or another, but what does that even mean? A herniated disc occurs when the nucleus pulposus (the soft center) pushes against the annulus fibrosus (the tough outer ring). If the disc bulges out toward the spinal canal, it applies pressure against the nerve root, causing pain.

 

Relief and Treatment for Cervical Radiculopathy

The majority of patients with cervical radiculopathy get better over time and do not require treatment, although there are options available to relieve discomfort. One such option is a soft cervical collar: a padded ring that wraps around the neck and allows the muscles to relax and limits motion.

Physical therapy is another option that can help relieve pain and improve range of motion while also strengthening neck muscles.

There are also many medications including nonsteroidal anti-inflammatory drugs, oral corticosteroids, steroid injections, and narcotics that can improve symptoms. 

If the nonsurgical teatment is not successful, surgery is also an option your doctor may recommend. 

 

Although there is nothing we can do to prevent getting old and wrinkly and eating mushy food, you can prevent cervical radiculopathy from recurring by maintaining proper posture, continuing regular exercise, being mindful of unnecessary forces on your spine (stop spending your days scrolling through Facebook), and keeping a healthy weight.



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Topics: anatomy and physiology

Do The Twist: A Look at a Torn Meniscus

Posted by Courtney Smith on Fri, May 13, 2016 @ 11:05 AM

I’m sort of glad I never played a lot of sports as a kid, mostly because I don’t have enough fingers to count all the friends I had who hobbled around on crutches or wore arm casts because of their sports injuries. The weirdest one was when my friend Ashley tore her meniscus. She came crutching into homeroom with her knee in a brace and gladly demonstrated what happened when she put any weight on it: her knee immediately buckled, nearly sending her to the floor. I vaguely remember there being a smattering of grudgingly impressed applause.

A meniscus tear is one of the most common knee injuries, particularly for those who play sports or do things that involve a lot of sudden stops and turns. Ashley played tennis, so I suppose it was only a matter of time before something tore.

Meniscus in context


We’re going to take a look at the meniscus, how and why it can be injured, and what can be done to treat and prevent injury.


The Meniscus: Fibrocartilage or Ticking Time Bomb?

Your knees bear the brunt of a lot of things, whether you realize it or not. Think of all you use your knees for: walking, running, using your foot to scratch an itch on your leg, helping you lift something heavy … even just simply bearing your own body weight. Your knees don’t handle all of this alone; there are a bunch of ligaments and fibrocartilage that help dissipate pressure and reduce friction.

The meniscus is one of these fibrocartilage heroes. Flat and curved, almost like a pad, the meniscus covers each tibial condyle. The medial section of the meniscus attaches to the anterior intercondyloid fossa of the tibia, while the lateral covers a large part of the auricular surface—it’s twisted on itself so that its free margin rests on somewhat of a sloping shelf of the front of the lateral process of the intercondyloid eminence. Which is a bit of a mouthful. Basically, it’s a hat for the tibia, as you can see here:

Medial meniscus

 

Do the Twist: A Torn Meniscus

Like I said above, tearing the meniscus is relatively common. It’s not just sports that can cause it to tear, either. Sometimes it’s just plain old age and degeneration—we’re not perfect machines, after all. Our parts are subjected to the same wear and tear as anything.

The most common cause of meniscal tears is due to twisting while loading the knee, such as during a tennis match or other sport. If the meniscus has weakened and grown thin due to old age, sometimes even just standing up can cause it to tear!

Symptoms of a torn meniscus include pain, swelling, catching or locking of the knee (because there’s cartilage flapping around), or like what Ashley had experienced in that her knee “gave way.”

Meniscal tears are categorized by type and location. Vertical tears are along the longitudinal axis, while horizontal tears are along the transverse axis. A common location for a meniscal tear is the posterior horn, pictured here:

Medial meniscus with a posterior horn tear

 

Up and Running: Diagnosis and Treatment for a Torn Meniscus

Despite the symptoms listed above, there are a few ways to know for sure if the meniscus has been torn. One way is to have an ultrasound, which a doctor will use to check out your knee while it’s in motion. If cartilage is flapping around in there and getting caught in the moving parts of the knee, the ultrasound will be able to show that. Another is to have a magnetic resonance image, or MRI, which uses radio waves and a magnetic field to produce surprisingly detailed images of soft and hard tissue—even a hard place to visualize like the inside of the knee.

If an ultrasound or MRI can’t produce a concrete result, an arthroscopy may be needed. In an arthroscopy, a small incision is made near the knee and an arthroscope (a camera and light source) is inserted into it to take a look around. The camera will produce an actual real-time image of what’s going on within the knee.

Depending on the severity of the tear, your doctor will prescribe one of several treatments.

If the tear isn’t too awful, you’ll most likely be told to rest your knee (you may even get crutches out of the deal) and to apply ice to reduce any swelling. Over-the-counter painkillers, like ibuprofen, can help both with pain and inflammation.

Physical therapy can be helpful in strengthening the muscles of the knee and the leg for better stability. Surgery can be successful in severe cases, either in repairing the meniscus or trimming it altogether.

 

So, be kind to your knees. Treat them like you would someone on a date: have fun with them, but don’t go too fast or else you risk ruining the night.



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Test/Treatment Source: "Torn Meniscus." Mayo Clinic. Tests and Diagnosis. Web. 13 May 2016.

Topics: learn muscle anatomy

The Virtual Reality Learning Center: Exploring Anatomy in a Flipped Classroom

Posted by Sofía Pellón on Thu, Apr 14, 2016 @ 08:41 AM

When I think back to dissection day in high school biology class, I remember these aspects the most: the overpowering smell of formaldehyde, getting too absorbed in the dissection process to be grossed out, and the fact that it was a one-time thing. I know we had plenty of other lab days in biology class, but the dissection lab is the one I remember best, because it was much more engrossing than usual.  

My surprisingly exciting lab day memory came back to me when I had the opportunity to interview Dr. Robert Hasel, whose top priority is keeping graduate students engaged and engrossed. A passion for technology fueled the debut in August of a virtual dissection lab at Western University of Health Sciences in Pomona, CA. As Associate Dean for Simulation, Immersion, and Digital Learning for the college of Dental Medicine, Dr. Hasel's ultimate goal is to give students an immersive experience with virtual dissection while they gain gross anatomy knowledge that lasts. 

The Virtual Reality Learning Center (VRLC) offers Western U’s health science students access to virtual dissection tools including an Anatomage dissection table, a zSpace table, and eight iPads equipped with Visible Body's Human Anatomy Atlas. Students in all of Western U’s health sciences colleges have access to the VRLC, which include:

  • osteopathic medicine
  • allied health
  • pharmacy
  • nursing
  • veterinary medicine
  • dentistry
  • optometry
  • podiatry
  • biomedical sciences 

 

Hasel_Class.jpg

 

Students in the VRLC hard at work on an activity

 

During a four-hour lab session, students rotate between learning stations in teams of two or four, practicing their anatomy knowledge through specific activities. At the Atlas iPad station, for example, students have to complete an activity in 15 minutes. In pairs, and armed with a preset identification list of anatomical structures, students explore an anatomy view. The goal is to identify the names of the anatomical structures and note an important feature of each one. Sometimes the students have a race to see which team can complete a quiz by correctly identifying the most structures in the shortest amount of time. 

Helping students and instructors adapt to the virtual lab has been a key element of the lab’s success. Here's are Dr. Hasel's tools of the trade:

  • A group of student facilitators who have taken a Masters program at Western U and completed the anatomy course, who help bridge the gap between faculty and students
  • Teacher and student manuals created by Dr. Hasel, to make sure nobody gets lost
  • An agenda and assignments for each learning station, to walk students through the process

With guidance and a little bit of an adjustment period, he says, students go from reluctant to energized. 

The concept of “hands-on” dissection is evolving, and Dr. Hasel emphasizes several reasons why virtual dissection is a valuable supplement—and a truly special teaching tool. Only about 5% of health science students have access to cadavers, he says, and those who do only get to spend a few hours per year in the cadaver lab. Of the 8-10 students in each group, "you have just one or two actually doing the dissection. And the tissue looks like beef jerky; it's not similar to human tissue that's alive. You can't tell one thing from another.” If students make a mistake in the dissection, they've ruined the cadaver, Dr. Hasel says, but with virtual dissection, if students make a mistake, they just refresh their screen. 

Dr. Hasel has been passionate about 3D imaging for many years. One of the great advantages he sees is that 3D models resonate with students in a way that 2D images don’t. In Dr. Hasel's words, learning in 3D "is how we learn in this world and how people form images in their brain."  

 

Hasel_Atlas1.png

Identifying an artery with Human Anatomy Atlas

 

In explaining the appeal of the virtual lab experience, he says, "This is not a PowerPoint in a lecture hall. Students are excited to get in there and get going. Engagement is the biggest difference. They have to interact with the learning activity they're assigned to at that station... It's an extreme contrast because it's not a passive environment. It's a four-hour lab and we have to kick them out." 

What really makes 3D learning technology useful, Dr. Hasel tells us, is building a skin of curriculum around the technology. It can take some adjustment for students and instructors to get used to switching both to a flipped classroom and to learning anatomy with 3D imaging. Compared to a lecture environment, it's a big change, but one that enables the knowledge to stick: "You’re taking responsibility for your own learning...for 26 years you're spoon-fed information, you're tested on it, then it goes away. The result with our lab is that students learn a lot more and can apply their knowledge to an everyday situation."  

 


 

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Topics: in the classroom

Into The Carpal Tunnel: Anatomy & Pathology of Carpal Tunnel Syndrome

Posted by Courtney Smith on Thu, Feb 18, 2016 @ 11:00 AM

It's what strikes fear into the heart of every frequent typist (like myself): carpal tunnel syndrome. I just shuddered as I typed that. It's usually referred to as "carpal tunnel," but the thing is that everyone has a carpal tunnel. Well, everyone has two: one in each hand.  But not everyone is affected by carpal tunnel syndrome (or CTS). About 3% of women and 2% of men will be diagnosed with CTS during their lifetime, with women at 3x the risk than men. That's over 9 million people in the United States alone.

But what is it exactly? Why is it such a common ailment? Why do more women have CTS than men? Why do some people have issues with their carpal tunnel while others don't? All very good questions. And my beleaguered wrists and fingers will do the answering.

 

What is the carpal tunnel?

The carpal tunnel is an actual tunnel created by the tendons, tissues, and bones in your wrists and hands. Think of the bones of your arm, wrist, and hand as a road. The flexor retinaculum and the palmar carpal ligament work like an overpass, and the flexor tendons of your hand and the median nerve pass under it like a car.

Flexor-digitorum-superficialis-carpal-tunnel-median-nerve.png

The flexors -- the flexor digitorum superficialis, the flexor pollicis longus, the flexor carpi radialis, and the flexor digitorum profundus (highlighted in blue) -- are muscles that originate in your forearm, but insert into the finger bones as tendons (which means technically you don't have muscles in your fingers). These tendons are what allow your fingers to flex, hold things, type, and do pretty much any task you can dream of. Also, when you bend your wrist, you are working the flexors in your forearms, as well as the tendons.

Poke the palm of your hand. That you felt anything at all is all thanks to the median nerve. The median nerve is part of the brachial plexus, which is a network of nerves in the shoulder and upper limb. It supplies sensation to the palm, the side of the thumb, and the index, ring, and middle fingers, as well to the flexor tendons. It also gives function to the muscles at the base of the thumb.

 

Carpal Tunnel Syndrome Symptoms

I can hear you asking, "If the body has this nice little system going with the muscles, tendons, and the median nerve… why in the world does that system break down?"

The thing is, no one is really sure what leads to carpal tunnel syndrome. CTS is caused by the tissues and tendons around the median nerve (with nerve branches, highlighted in blue) swelling and pressing on the nerve. This reduces oxygen flow to the nerve, which means the signals to the nerve slow. In some cases, it's not the tendons that swell but the nerve itself.

The compression of the median nerve results in pain, numbness, parathesia ("pins and needles"), and a feeling of coldness in the wrist and hand -- with the exception of the little finger. The median nerve does not provide sensation to the little finger and therefore it remains unaffected.

 Carpal-Tunnel-Median-Nerve-Flexor-Digitorum-Wrist.png


Why is CTS so common?

CTS is associated with repetitive actions that directly affect the wrist/hand area, such as frequent typing or computer use, but manual labor is actually the occupation with the highest CTS risk. Musicians, welders, sheet metal workers, cooks/chefs, laborers in the freight and/or moving industry, and office workers are at the highest risk for CTS. Think of how much you use your hands and fingers during the day to complete certain tasks. I, myself, am well on my way.

 

Can you prevent carpal tunnel syndrome?

So, how do you prevent it? If you catch it in the early stages, CTS is reversible. There are two key strategies to stopping the onset of CTS: rest and ergonomics.

  1. Rest periods are important, especially for you heavy typists out there. Resting your fingers for short periods of time (3 minutes or so) will be enough time for the tissues to relax. Shaking your hands out to loosen things up is always a good idea too.
  2. Ergonomics is also very important. Ergonomics is the efficient interaction between you and your workspace. For example, when you use a computer, do you have a wrist rest for your keyboard or mouse? Wrist rests are not only for comfort but they help keep your wrists and hands parallel to the device you're using, easing the strain on the muscles. How about your chair? Does it have arm rests? Is the back positioned to encourage good posture? The same goes for those who use tools or manual equipment. Make sure what you use does not put unnatural stress on your wrists. If you use, say, a wrench, make sure that when you hold it for use your wrists are in the same, comfortable position they'd be in if your arms were hanging at your side.

CTS is easy enough to prevent, but if you've been experiencing CTS symptoms for a while you may be a bit out of luck as far as reversing it. But adopt some good habits and you'll prevent the symptoms from worsening.

There you have it: carpal tunnel syndrome, demystified. Now it's time to give my fingers a break.

 


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Carpal Tunnel Syndrome: New York Times.

Topics: learn muscle anatomy, anatomy and physiology

Anatomy and Physiology: The Pharynx and Epiglottis

Posted by Courtney Smith on Fri, Feb 12, 2016 @ 08:30 AM

Once upon a time, I almost died.

I was two years old and at my grandmother’s house, where my cousins were having a blast trying to find the plastic Easter eggs my grandmother had hid. You see, inside the eggs were quarters, dimes, and nickels. And, if you were lucky, you would stumble upon big plastic eggs, which had dollar bills inside them. But, being two, I wasn't really able to participate. That didn't stop me, though. I stumbled around on my stubby legs and happened upon a plastic egg, inside which were a quarter and a nickel.

Naturally, I scooped out the change and shoved them in my mouth.

The next few minutes were kind of chaotic, what with me choking and turning blue, slipping slowly into unconsciousness, while my grandmother screamed at the 9-1-1 operator to make the ambulance drive faster and my mother tried to perform the Heimlich on my little body to no avail. They realized with horror that the ambulance wasn’t going to make it in time. My dad—thinking fast, or not at all—pried my mouth open and stuck his fingers down my throat. Pretty far, according to my mother. He managed to drag the coins up out of my throat and out of my mouth, which was incredibly lucky, as he had a much better chance of pushing them down even further and sealing my fate. The paramedics arrived some minutes later and declared me A-OK. That day left me with a cool story to tell 24 years later and my parents with a healthy fear of coin currency.

Why did I tell you this story? Because this is a great example of the pharyngeal reflex, or gag reflex, which your body employs to prevent unwanted things (such as coins) from entering the lungs. The digestive system and upper respiratory system share many of the same structures, so to make sure everything goes where it’s supposed to, the body has certain vanguards in place. Let’s take a look at them!

 

Oral Cavity

The oral cavity, oropharynx, nasopharynx, and laryngopharynx

We’re all pretty familiar with this structure. The oral cavity is the inside of the mouth, an oval-shaped cavity located anteriorly to the pharynx at the start of the alimentary canal. The front of the cavity is bound by the inner surface of the lips and cheeks to the gingiva (gums) and teeth. The cavity floor is defined mostly by the tongue and the roof is formed by the hard and soft palates.

Food is masticated (chewed) in this cavity by the teeth and tongue, mixed with saliva containing enzymes to help break down carbohydrates. The mass created by this process is called a bolus, which is then swallowed.

The oral cavity is also an airway for the respiratory system.

 

Pharynx

The pharynx is a large musculomembranous tube that functions in both the respiratory system and the digestive system. It is made up of three sections:
 

1. Nasopharynx

Nasopharynx in context

This portion of the pharynx begins at the back of the nasal cavity, situated behind the nose and above the soft palate. Unlike the other two portions of the pharynx, the nasopharynx remains open all the time. On each lateral wall is the pharyngeal opening of the Eustachian (auditory) tube. The nasopharynx functions as an airway in the respiratory system. Also contained within the nasopharynx are the adenoids, or pharyngeal tonsils.

 

2. Oropharynx

Oropharynx in context

The oropharynx is the middle portion of the pharynx, working with both the respiratory and digestive systems. It opens anteriorly in the mouth and extends from the soft palate to the hyoid. In each lateral wall is a palatine tonsil; also in this region are the sublingual tonsils, which are under the tongue. The oropharynx functions as an airway and as part of the alimentary canal.

 

3. Laryngopharynx

Laryngopharynx in context

This is where my near-death experience could have gone either way. The laryngopharynx is the posteriormost inferior region of the pharynx, reaching from the hyoid to the lower border of the cricoid cartilage; it’s the place where the respiratory and digestive systems diverge.

The rear of the laryngopharynx becomes the esophagus and continues into the digestive tract, while the front of the laryngopharynx merges with the entrance of the larynx. The epiglottis, a structure in the laryngeal skeleton, helps direct food toward the esophagus, preventing food and liquids (and coins) from entering the trachea.

 

Epiglottis

Larynx-superior-larynx-laryngeal.png

I have a love/hate relationship with the epiglottis. On the one hand, I think its function in the respiratory system is fascinating, and I have it to thank for trying to keep the coins from entering my lungs; on the other, I loathe it for all the extra work it made me do in my college linguistics course. If I hear the words “glottal stop” ever again, I will not be responsible for my actions.

The epiglottis is a leaf-shaped cartilaginous structure that is part of the laryngeal skeleton. It’s usually directed upward toward the pharynx, like an open door through which air passes to the trachea. During swallowing, muscles pull it down to close the entry to the larynx—closing the door, so to speak—to prevent food, liquid, and saliva (and coins) from entering the trachea.

Now apply that principle to the stoppage of air. The epiglottis is pulled down to stop air from entering the trachea. For example, you tend to create glottal stops in words that end in t+vowel+n. The word “button” sounds like “butt-n” when spoken—you don’t tend to vocalize the vowel. The vocal cords close sharply, the epiglottis comes down, and no air is passed.

Also, if you’ve ever swallowed the wrong way, you’ve experienced that quick panic and awful seizing in your chest. This is the pharyngeal reflex, or gag reflex, acting to expel whatever you swallowed before it can enter the lungs. Sometimes the reflex is very sensitive, and even accidentally pushing your toothbrush too far can set it off! Your body very much doesn’t want you to asphyxiate; I wish two-year-old me had received that memo.

 

 

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Year-End Roundup: Five Coolest Medical Stories of 2015

Posted by Courtney Smith on Tue, Dec 29, 2015 @ 02:31 PM

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Well, it’s that time again! Throughout the year, we keep an eye out for the most amazing, bizarre, and unbelievable breakthroughs of the health science community. Here are five of our favorite medical stories of 2015.

 

Brain-to-Brain Communication

In 2013, writer-director Guillermo del Toro brought Pacific Rim to the big screen. The film centered around the idea that two people would connect to each other’s brain and work together to pilot enormous, mechanized robots. Everyone laughed a little at the thought: that kind of “neural link” was not just impossible but dumb. How could two minds link to do anything?

Well, apparently we all should’ve enjoyed that laugh, because in 2015 a study out of the University of Washington succeeded in performing the first direct brain-to-brain interfacing between two people. Five sets of participants played real games (one being very similar to Twenty Questions) and control games—in dark labs miles apart, wearing ear plugs.

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While this demonstration of a “neural link” is believed to be the first of its kind, more tests and studies are sure to follow. Sometime soon, science fiction may become science fact. Now it’s just a matter of playing the waiting game for giant robot suits.

Read the full study in the peer-reviewed journal PLOS ONE.

 

The New Way of Taking Ibuprofen: A Patch

Bottles of Ibuprofen lining the shelves of the pain reliever aisle of your local pharmacy may soon be a thing of the past with this year’s invention of an ibuprofen patch by researchers at the University of Warwick, led by research chemist David Haddleton.

Currently there are pain-relieving patches available commercially, but this patch is the first to deliver ibuprofen through the skin.

Ibuprofen taken orally can pose a risk to one’s stomach lining, and may cause ulcers or stomach bleeding. This patch circumvents those risks, enabling the drug to be delivered at a steady rate through the skin over a 12-hour period.

Read the full press release here.

 

The First Successful Penis Transplant

Yep, that’s right!

Coming hot on the heels of the first successful uterus transplant in 2013, a surgical team in South Africa led by Andre van der Merwe, head of Stellenbosch University’s Division of Urology, attached the penis of a deceased donor to a 21-year old patient who lost his penis during a ceremonial circumcision. The surgery lasted nine hours.

This is the first successful donor transplant. In 2008, a Chinese man had a donor penis successfully transplanted following an automobile accident, but 10 days later asked for it to be removed due to psychological trauma.

Months after the surgery, not only has the transplanted penis been functioning normally, but it even resulted in a pregnancy!

Read the full story of the surgery here.

 

Eye Drops That Melt Away Cataracts

Cataracts, a buildup of protein in the lens that prevents light from reaching the eye, are the leading cause of blindness in the world (and the leading cause of vision loss in the United States). Cataract surgery can be painful and invasive but is the only way of removing them to restore vision. Until now.

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A team of ophthalmologists and scientists at the University of California (UC), led by molecular biologist Ling Zhao, has developed a new drug that—when applied to the eyes in the form of liquid drops—dissolves cataracts.

After discovering that children with a genetically inherited form of cataracts shared a mutation that stopped the production of a steroid called lanosterol, but their parents produced lanosterol and had no cataracts, the team postulated that lanosterol might be the key to either reduce or even prevent cataracts. They tested their lanosterol-laden solution on a model of a human lens, as well as a series of rabbits and dogs that had cataracts, and the results were fantastic: the solution significantly reduced (or even removed altogether) the animals’ cataracts, as well as that of the human lens model.

Next step? Adapting the solution for human use.

Read the full study in the peer-reviewed journal Nature.

 

Scientists Breach the Blood-Brain Barrier for the First Time

The body has tons of defenses against toxins and the like, but none more powerful than the blood-brain barrier, which prevents pathogens from reaching the central nervous system. But a team at the Sunnybrook Health Sciences Center in Toronto has found a way to temporarily breach the barrier for the first time.

Patient Bonny Hall had been managing her brain tumor for years, but the tumor had begun to grow and, without a targeted, aggressive treatment, would continue to do so. 

The treatment used gas-filled bubbles to punch temporary holes in the blood-brain barrier via an injection into Hall’s bloodstream. This was followed by application of focused ultrasound waves, which caused the bubbles to expand and contract at a rate of about 200,000 times a second and punch temporary holes in the endothelial cell layer of the blood-brain barrier. This allowed the team to deliver chemotherapy drugs to reach the tumor.

An additional 10 patients are scheduled to receive the treatment in the hopes it will manage their brain tumors.

“Breaching this barrier opens up a new frontier in treating brain disorders,” Neal Kassell, chairman of the Focused Ultrasound Foundation, said in a press release. “We are encouraged by the momentum building for the use of focused ultrasound to non-invasively deliver therapies for a number of brain disorders.”

Read the full press release here.

 


And that brings 2015 to a close.

Here's to 2016 and the new and interesting stories it will bring!


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Topics: 2015

5 Facts to Know about the Senses

Posted by Sofía Pellón on Wed, Dec 16, 2015 @ 04:14 PM

Your senses are a big part of your life! They tell you what’s happening right from when you wake up in the morning: you open your eyes and see if it’s sunny or cloudy out, hear an alarm clock or somebody waking you up, and maybe smell breakfast cooking!

We’re talking about sight, smell, and hearing in My Incredible Body, and we’re here to give you a preview.

1. Your eyes are really good at seeing, but they can’t do it alone – they need to work with your brain to make it happen. The way your eyes communicate with your brain is through the optic nerve. The optic nerve sends signals from your eyes to your brain, and those signals turn into a message that allows you to see everything from the blog post you’re reading right now to your favorite movie.


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2. Even if you never wear contact lenses to correct your vision, you always have a lens in each of your eyes. The lens is a curved membrane that helps put the images you see into focus.

Fun fact: The colored part of your eye is called the iris, and it’s named after the Greek goddess of the rainbow!

3. The inside of your nose is called the nasal cavity, and there are special nerves hanging from the roof of it that detect the smells when you breathe in. Those nerves send a signal into your brain to translate what you’re sensing into a smell.

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4. Ever wondered how the ear drum got its name? It really does work like a drum. It’s a membrane that vibrates when sound hits it, just like the surface of a drum vibrates when you hit it with a drumstick. That vibration creates sound waves that travel through your ear so you are able to hear.

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5. Your outer ear isn’t just for looks – it also has a job to do! Its funnel-like shape allows it to collect sound waves and send them inside the ear to your brain.

Fun fact: Earwax has a purpose, too! It’s a protective barrier to keep dirt from getting inside your body.




All of the images and most of the text come from My Incredible Body: Amazing Anatomy Just for KidsWinner of a Parents’ Choice Silver Honor Award. 

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Topics: teach kids anatomy

Topics: teach kids anatomy

Anatomy and Physiology: The Pitfalls of LDL Cholesterol

Posted by Courtney Smith on Fri, Nov 13, 2015 @ 12:10 PM

As I get older, I try to be conscientious of what I eat, but the problem is that I'm always craving mac & cheese and there's nothing I can do about it. Resisting the urge to shove a block of sharp cheddar down my gullet with a macaroni chaser is, as they say in "Star Trek," futile. No matter how much I fight it, I eventually cave. My doctor isn't impressed. "Stop eating things so high in cholesterol," she pleads, and I nod seriously and say, "I hear what you're saying, but let's be realistic."

And so it goes.

More and more, we're warned about foods that are high in "bad" cholesterol and the dangers of having high cholesterol, but what does it all mean? Read on to find out!

 

Cholesterol: What Is It and Why Do We Have It?

Cholesterol is a waxy substance that helps maintain the structure of all of your cells and performs certain tasks, like producing hormones and vitamin D, as well as helping you to digest your food.

Red blood cells flowing through an artery

On its own, cholesterol isn't inherently "bad." In fact, your body—particularly your liver—produces all the cholesterol it needs!

So, where does it all go wrong? Why do so many people have high cholesterol levels? Well, look no further than the foods you eat. Meat, butter, shellfish, cheese, and pastries all can be very high in cholesterol, which is a bummer because everyone knows that lobster mac & cheese is the best kind of mac & cheese on the planet. Obviously eating these things in moderation is fine, but too much of a good thing can be bad for you (except ice cream*).

 

The Good, the Bad, and the Ugly:
Two Types of Cholesterol

Like a Hollywood classic for which I'll probably be sued for naming, "good," "bad," and "ugly" characteristics can be applied to cholesterol.

Two types of proteins carry cholesterol through your bloodstream: low-density lipoproteins and high-density lipoproteins, and too much of one or not enough of the other isn't a good thing. It's important to try and maintain a healthy balance between them.

Cholesterol traveling with blood cells and other substances through an artery

HDL cholesterol is the "good" cholesterol, as it carries cholesterol from other parts of your body back to the liver, which then removes the cholesterol from your body.

LDL cholesterol is "bad" because a high level of it can lead to a buildup of it in your arteries.

A buildup of LDL cholesterol is "ugly" because it can lead to a bunch of issues. Actually, why don't we talk about those right now?

 

The Good, the Bad, and the Ugly 2:
Electric Heart Disease Boogaloo

Ah, coronary heart disease: the one threat that gets me on my feet and forces me to stay somewhat active. As we discussed previously, CHD is no joke.

What does heart disease have to do with cholesterol? A lot, actually. See, when there's a buildup of LDL in your artery walls, it narrows the amount of space through which blood travels. Add a buildup of other things, like calcium and fat, and you get plaque. When plaque accumulates in the arteries, it's known as atherosclerosis. When less blood flows, your organs don't get the amount of oxygen and nutrients they need. This can lead to stroke, heart attack, or even death.

An artery narrowed by plaque buildup, showing atherosclerosis

In CHD, the arterial walls of the heart become hard with plaque buildup and grow narrow, limiting oxygen to the heart. When there's a limited or lack of oxygen flow, tissues will die and heart attack can occur.

According to the Center for Disease Control, a whopping 73.5 million adults in the United States have a high LDL cholesterol level, which puts them at double the risk of heart disease than someone whose levels are normal. A high LDL cholesterol level usually doesn't come with symptoms, so many people have no idea if their blood cholesterol level is too high. Exercising, eating well, and not smoking will lower your risk of heart disease.


While it may be impossible for me to give up mac & cheese completely, I can certainly curb my intake. It won't be easy, but it's important. My very life may depend on it.

* I’ve been told that this is just wishful thinking on my part.

 

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Further Reading:

1. CDC.gov

2. National Heart, Lung, and Blood Institute

3. Heart.org

Topics: anatomy and physiology