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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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Topics: anatomy and physiology

Year-End Roundup: Five Coolest Medical Stories of 2015

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

VB_Stories2k15-banner.png

 

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.

Brain-to-Brain-Communication-BBI.png

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.

Melt-Away-Cataracts-Lanosterol.png

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.


My-Incredible-Body-Eyes-Extraocular-Muscles-Ocular-Nerve.png


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.

My-Incredible-Body-Nasal-Cavity-Sneezing-Nose-Tickle.png

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.

My-Incredible-Body-Middle-Ear-Hearing-Stapes.png

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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- Learn Muscle Anatomy: Of Dads and Rotator Cuff Injuries
- Anatomy and Physiology: 7 Facts about Cardiovascular Disease



Further Reading:

1. CDC.gov

2. National Heart, Lung, and Blood Institute

3. Heart.org

Topics: anatomy and physiology

Anatomy and Physiology: Five Things About The Integumentary System

Posted by Courtney Smith on Tue, Oct 20, 2015 @ 03:30 PM

For all we talk about taking care of our organs, we always seem to leave out one of the most important and obvious. The integumentary system—which is comprised of your hair, nails, and skin—protects everything inside you, acting as a barrier to keep your bones, organs, and muscles safe and sound. It’s one of the many things about our anatomy we take for granted.

The integumentary system is a pretty amazing structure. So amazing, in fact, that it deserves its own post. Let’s take a look at it.


Integumentary skin

 

1. The integumentary system is one big, busy organ

That’s right! The integumentary system is the body’s largest organ, absorbing nutrients (from the sun and other sources), regulating internal body temperature (which is why you’re miserable on hot days, but not as miserable as you could be), and eliminating waste (sweat, anyone?).

It also has a very high cell turnover rate—in one year, you’ll shed over 8 pounds of dead skin! In fact, what you see on your body is dead skin waiting to be sloughed off while everything else is beneath the surface.

 

 

2. The skin is made up of several different types of cells

Each type of cell contributes to the skin in different ways. The epidermis, the outermost layer of skin, is made up of melanocytes, keratinocytes, Merkel cells, and Langerhans cells. At least two of those should look vaguely familiar to you.

Melanin is pigment, which absorbs ultraviolet rays and determines skin color. The more melanin you have, the darker your skin is.

Keratin is a fibrous protein that protects skin and tissue, and it also is the key structural material in hair and nails.

 

 

3. Your skin is divided into layers

Integumentary epidermis dermis hypodermis skin keratinocytes melanocytes

You know this one, though. But did you know that the skin is categorized by three layers, which are then broken down into sublayers?

The three main layers of the integumentary system are the epidermis (outermost layer), dermis (middle layer), and hypodermis (innermost layer).

We’ve gone over the epidermis already, but what about the other two layers? The dermis is a thick layer composed mainly of connective tissue rich in collagen and elastin. The dermis stores water, regulates body temperature and the production of vitamin D, cushions the body, and supplies blood to the epidermis.

The hypodermis is the subcutaneous layer and is composed of mainly adipose (fatty) tissue and collagen-rich connective tissue. It separates muscle from skin, stores fat, and conserves body heat.

 

 

4. Your fingers are primed to detect touch

epidermal cells meissners corpuscles touch skin integumentary

There’s a reason you use your hands to feel around in the dark, and it’s not just for balance! Special receptors (free nerve endings) called Meissner’s corpuscles are divvied up around your skin, but are concentrated in places more sensitive to touch, such as your fingers.

 

5. A special muscle causes goosebumps

Integumentary arrector pili dermis hypodermis skin keratinocytes melanocytes

We’ve all experienced goosebumps before—usually when you’re cold or afraid (or, in my case, when you watch the last 20 minutes of Close Encounters of the Third Kind). But have you ever given thought as to what causes goosebumps? What is in your skin that makes it pucker in such a way? The answer is small muscles known as arrector pili.

The arrector pili muscles (one for each hair) extend from the dermis and attach to each hair follicle, just above the bulb. Hair is sensitive to touch, changes in temperature and air, as well as in reaction to an emotion (e.g., hearing beautiful music, seeing something amazing, the last 20 minutes of Close Encounters, etc.), and the arrector pili muscles contract in response to these physical and emotional changes. When the muscles contract, the hairs stand on end.

 

The integumentary system has a low rate of permeability (a.k.a., it’s hard for things in the environment to penetrate it), which makes it the perfect protector for the rest of the body systems.

 

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- Anatomy and Physiology: Stroke Is No Joke: Always Act FAST
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- Anatomy and Physiology: 7 Facts about Cardiovascular Disease



Sources:

1. Care for conditions from acne to wrinkles 

2. Advances in treating eczema and dermatitis

3. Dermatology pictures, Hardin Library for the Health Sciences, University of Iowa

4. A video that shows the development of skin cancer

 

 

Topics: anatomy and physiology

Camp Neuro: The STEM Summer Camp Everyone's Talking About

Posted by Courtney Smith on Tue, Sep 22, 2015 @ 03:00 PM

At my high school, Anatomy & Physiology was one of the hardest courses to pass. It was also the hardest course to join because of the sheer number of students who wanted to take it. If there had been a summer program geared toward A&P, the waiting list to get in would have been endless. But, like the after-school astronomy club I tried (and failed) to start, nothing of the sort was offered.

But that was over 10 years ago. School programs are changing. The internet has opened a myriad of doors and has helped people to connect and be vocal about various shared interests. Thanks to the power of the web, a new program is working its way up the ranks.

Camp Neuro is a week-long STEM summer camp run by local medical students and has cropped up in 18 cities nationwide over the last two years. Their mission is to give high school students interested in medicine or psychology an introduction to those fields, with a focus on the care and maintenance of the brain.

When you think “summer camp,” you no doubt jump to the image of kids throwing themselves into lakes and roasting marshmallows over a fire. Not at Camp Neuro, where by 9 a.m. the campers are wrist-deep in a pig brain or learning how to tie surgical knots.

Camp Neuro students in a workshop with medical professionals.
In the middle of a workshop. (Camp Neuro, Dallas–Ft. Worth, TX, 2015)


My sister works in the field of pediatric neurology, and if she ever found out about this she’d flip. She would’ve killed for something like this when she was in school.

Each day is filled with workshops, interesting A&P lectures, exercise, and special guest speakers from different fields—all of which give the campers a taste of real-world medicine careers, ranging from physical therapy to neurosurgery. A typical day looks something like this:

A typical day at Camp Neuro
(campneuro.com/description.html)


We were able to talk with Sohail Kamrudin, a second-year medical student at the Texas College of Osteopathic Medicine, who was the Medical Student Director of Camp Neuro during its run in Dallas–Fort Worth this past July. He and his fellow team members used Visible Body’s brain model as a visual reference for the campers during lectures.

Cross-section of the human brain within the context of the skull

A cross-section of the brain (from Human Anatomy Atlas)

“Your app provided a great learning experience for our attendees,” Kamrudin said. “Seeing the brain from different angles really helped our campers understand it. We ended up building a brain from the brainstem up.”

Camp Neuro isn’t alone in its venture to invigorate enthusiasm for medicine and health. Its sister camp, Camp Cardiac, introduces the basics of cardiology to its campers through hands-on workshops and interaction with professionals. As of right now, there isn’t a Camp Respiratory or Camp Lymph, but who’s to say that won’t change, especially when you see testimonials like this:

“I LOVED my week at Camp Neuro. My only complaint is that it went by too quickly! :-) I learned so much, and made a lot of friends! I’m planning to apply to Camp Cardiac next summer!”
S.T. — Pasadena, CA

“My son said it was his best camp ever! I am blown away by how much they covered in only 1 week. He loved everything but his favorite part was the brain dissection. He also loved the counselors, as they were so positive and fun. Thank you so much for putting together such an amazing program for young people.”
P.L. — Silver Spring, MD

“Our son truly had an amazing time at Camp Neuro. The camp ended a couple of weeks ago and he’s still talking about experience. He is now seriously considering becoming a doctor. Thanks so much for everything!”
R.H. — New York, NY


So here’s to Camp Neuro and Camp Cardiac, paving the way for our future medical practitioners and educators, one pig dissection at a time.

Students of Camp Neuro, Dallas–Ft. Worth, TX, 2015
The medical professionals of the future. (Camp Neuro, Dallas–Ft. Worth, TX, 2015)

 

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Read further.

- Anatomy and Physiology: 5 Things about the Integumentary System
- Anatomy and Physiology: The Limbic System
- Anatomy and Physiology: 5 Cool Facts about the Middle and Inner Ear

Topics: teach kids anatomy

Learn Muscle Anatomy: Of Dads and Rotator Cuff Injuries

Posted by Courtney Smith on Wed, Jul 29, 2015 @ 11:04 AM

If my dad tells me about the hockey game that led to him tearing his rotator cuff one more time, I’m going to tear the rest of his arm off and beat him with it. I’d rather he’d relive his glory days a little less and focus more on being seen by a doctor for his rotator cuff issues. But because he never got adequate help with his rotator cuff tear when he was younger, I’m doomed to a lifetime of watching His Stubborness wince every time he scratches the back of his head.

Dads. Am I right?

What is the rotator cuff, though, and why does an injury to it have such an impact? Read on! If you’re my dad, read on and then please go see your doctor.

Rotator-cuff-supraspinatus-subscapularis-teres-minor-infraspinatus


The rotator cuff is a group of muscles and tendons that surround the shoulder joint. These muscles keep the top of the upper arm in the shoulder socket by forming a "cuff" that not only holds the arm in place but helps it move in various directions.

The rotator cuff muscles hold the ball at the top of the humerus firmly in the glenoid fossa. The rotator cuff muscles are the supraspinatus, subscapularis, infraspinatus, and teres minor.

 

 

Origin

Insertion

Action

Subscapularis

Subscapular fossa

Lesser tubercle
of the humerus

Medial rotation of the head of the humerus; prevents anterior displacement of the humerus

Supraspinatus

All of the supraspinatus fossa

Greater tubercle
of the humerus

Assists the deltoid in abducting the arm; stabilizes the glenohumeral joint

Infraspinatus

Infraspinatus fossa on the posterior surface of the scapula

Greater tubercle
of the humerus

Laterally rotates the upper limb; stabilizes the glenohumeral joint

Teres minor

Lateral border of the scapula

Greater tuberosity
of the humerus

Lateral (external) rotation of the humerus; helps protect and stabilize the shoulder joint

 

Rotator Cuff Injury

When my dad was in high school, he played on our hometown hockey team and ended up… in a fight? In a dogpile? A ninja battle? I don’t know, I feel like the story’s changed over the years. Regardless, he tore his rotator cuff while tending goal and, thanks to our family’s particular strain of stubbornness, never got it properly checked out. It’s been plaguing him ever since.

Rotator-cuff-tear-supraspinatus


Tears are typically categorized in two ways: if they have partial thickness or full thickness, and if the tears are traumatic or degenerative. Gradual degeneration, like repetitive overheard motion of the shoulder (think of baseball pitchers), or sudden traumatic events (my dad at hockey) can tear one of the muscle tendons of the rotator cuff. It’s usually a torn supraspinatus that ends up causing the bulk of the issues.

Rotator cuff tears usually occur at the insertion point on the head of the humerus so that the tendon will no longer fully attach to the bone. Want to see it in all its gruesome action? You’re in luck! We’ve got a super short animation about it:

 

 

Symptoms of a rotator cuff injury include pain, decreased range of motion in the shoulder, and muscle weakness.

Treating a rotator cuff injury can range from easy (physical therapy being the most common) to invasive (surgery). I’ve been hounding my dad to have surgery on his shoulder for years, but he hasn’t budged yet. I’m not sure what he’s waiting for.

There are several types of surgery to treat the rotator cuff, including open tendon repair – in which a surgeon reattaches the tendon to the bone – and shoulder replacement – in which a surgeon installs the ball part of the artificial joint onto the shoulder blade and the socket part onto the arm bone (but this is reserved for only the most massive rotator cuff injuries coughdadcough).

Minor rotator cuff injuries will heal on their own with plenty of ice, rest, and daily shoulder exercises. If you do end up suffering a more involved injury, do literally the opposite of my dad and have it evaluated by a doctor. It may be one less story to tell at family gatherings, but you’ll be saving yourself a lifetime of pain.

 


 

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Topics: learn muscle anatomy