Pink Flamingos and Cochleas

I was planning to do a piece on the workings of the ear, how we hear.

The ear is fascinating.  A complex mix of cartilage and bone tunnels, moving membranes, tiny tiny bones (although still the only bones that are full size when we are born), our own amplification system, liquid filled coils, sensitive hairs and electrical impulses.  It allows us to hone in on particular noises, it can help us identify the direction the sound is coming from.  Without it our interactions with the world would be different.

And then…

Yesterday I ran a team building day.  We started with an ice breaker, an exercise in listening.  Each person had to greet another person, introduce themselves and say what they had recently watched on TV, their partner would reciprocate and then they would both move on to find different partners.  Simple enough.

Someone in the room had a secret message.  This person would introduce themselves and then say

‘The pink flamingos fly south over the artic.’

A fairly distinctive message for a number of reasons.  Once this message was passed on (it couldn’t be repeated) the person would resort to the conversations about TV programs with their next partner.

We did this for about 5 minutes.  At the end, I asked the person with the secret message to identify themselves. They all knew there was a secret message and they had to pass it on so you would have hoped they were waiting for it.   There were two of them!  What was the message?

‘The crows fly up through the clouds.’

In light of this experience (which I am sure is not unique to our team) I would like to revise my explanation of how hearing works.

Sound waves travel through the air and are channeled into the ear canal by the external auricle.  The sound waved travel down the ear canal and cause the tympanic membrane (ear drum) to vibrate.  This in turn causes movement in the three auditory ossicles, the malleus, the incus and the stapes in the middle ear.  The base of the stapes is in contact with the oval window of the cochlea.  The movement of the stapes causes the oval window of the cochlea to move and this, in turn, causes the fluids inside the cochlea to move.  This movement is detected by hair cells inside the various compartments of the cochlea.  These cells generate signals which are taken by the auditory nerve to the brain.

These signals enter the brain at which point it makes up the message that it thinks you should be hearing and directs this to the parts of your brain that should have been paying attention.

Does that sound about right?

Akimbo

Akimbo – it’s not a phrase you often come across.  I was introduced to it in Peter Pan.  It’s used to describe the way the characters stands – arms akimbo.  It describes the action of standing with your hands on your hips with the elbows splayed outwards.

 

I was provided with a nice illustration of the pose a few weekends ago (it may well have been because the people involved were wishing they had never grown up, like Peter Pan!)

 

I was watching  a Scottish Touch Competition.  As training for the Under 18 Scottish touch rugby team they are taken to these competitions to play against adult teams.  You can maybe imagine the emotion of these middle aged players when they come face to face with the national youth team on the field.

This was the view I was provided with half way through the game.

You can see three players with arms akimbo and a fourth player with their hands on their knees.

Why are they standing like this?

They are knackered!

But why do we adopt this position when we are tired?

This is the body taking control and making it easier for us to breathe.  But how does this work?

It comes down to the action of breathing and kinetic chains.

We have a number of muscles that connect our arms to our body.  These are usually used for moving our arms around.  The pectoralis major and minor, the serratus anterior and the latissimus dorsi all connect our arms to parts of our thoracic cavity.  The end of the muscle connected to the ribs is usually held in place while the muscle contracts to move our upper limbs about. Our arms are free to move around, they are the end of an open chain.

When the body needs more air it makes us close that kinetic chain.  You put your hands on your knees, your hips or behind your head.  You close the chain by fixing your arms.

Now when those muscles contract the arms can’t move and so the other end of the muscle moves.  It pulls on the ribs and it aids with the expansion of the rib cage so that you can get more air into your body and recover.  These muscles are known as the accessory muscles of respiration.

Arms akimbo might be part of the power pose, you’re getting in more oxygen so that you can make you move but in a physical situation like this  it sends a message to your opponents that you are tired.

The things we do to our bodies

When you study anatomy you develop this tendency to people watch.  Whether its looking at people who walk past the coffee shop and seeing how many people in high heels can actually straighten their legs or whether it is looking at artistic performers or movement specialists in wonder.

No where is this more prominent than in sport.  The things that sports people put their bodies through, or are able to do with their bodies can be just amazing.

The distinctive kicking style of Tayla Harris is nothing short of the full splits performed whilst sprinting, no break in stride.  Whilst recent pictures on social media have prompted some repulsive comments very few have risen to the challenge of recreating the photo of the kick.

On a recent trip to America I filmed this baseball player.  Just look at the position he gets into, effortlessly.

The problem, of course, is if you push yourself to the limits at some point you are going to find them and things are going to go wrong.

The various tests for knee ligaments are something that I have performed a few times.  The cruciate ligaments hold the knee joint in place.  The Anterior Cruciate ligament (ACL) stops the femur from moving too far backwards in the joint and the Posterior Cruciate ligament does the opposite.

You test the ACL with the anterior drawer test.  The knee is bent at right angles, the foot stabilised and, with the hands behind the joint to check the hamstrings are relaxed you gently see if the tibia will move forward in the joint.  There should be some movement but not much.

It’s the same problem as a lot of these tests.  They are usually demonstrated on someone who has in tact ligaments.  Its very similar to the cranial nerve tests which are usually demonstrate with someone who has functioning cranial nerves.  How do you know what the normal range of movement is?

This week a sports injury from 2014 almost ‘broke’ the internet.

In the 2014 rugby game where South Africa took on Wales, Jean de Villiers suffered a horrific knee injury.  I’m not going to post a video of the injury because it is shocking.  If you want to see it you can find it on the internet but it is not for the faint hearted.

It was thought he would never walk again.  He had numerous operations and he made it back to playing rugby.

This week he was demonstrating on instagram that his knee was a bit loose.

That is too much movement!  And yet he is walking around on it – the body finds a way.

In the week that we also lost Niki Lauda, and realise the things his body went through and he put it through during his recovery, it’s amazing to look at what some people are prepared to put their bodies through to pursue their dreams and equally amazing what the body is capable of.

Ears and Airplanes

I’ve just returned from a trip to the USA.  I was at an anatomy conference talking about my involvement with Anatomy Nights.

If you aren’t aware of it then go over to Anatomynights.com and consider coming along to our next event.

Anyway one of the first things I thought I would explain from this trip is why your ears pop when you go up and down in an airplane.  We have all experienced it, that muffling deafness and discomfort in your ears as you take off or land.  Your mother may have told you to yawn, your father may have told you to suck a sweet, your brother may have told you to hold your nose and mouth and blow.  They are all telling you to do the same thing – open your Eustachian tube.

We aren’t meant to use eponyms anymore in anatomy so to give it its proper name it is the pharyngotympanic tube, but if we did that I wouldn’t be able to tell you about the Italian Bartolomeo Eustachi who discovered the tube along with all the bones of the inner ear.  His greatest work, Anatomical Engravings, was finished in 1552 but not published, due to religious restrictions on anatomists until 1714, when it became a best seller, a century after he died!

Anyway, the tube connects the back of the throat with the middle ear, as seen in the diagram.  The pressure either side of the ear drum is usually the same but when we ascend rapidly the pressure inside the ear becomes greater than the cabin pressure and the ear drum is forced outwards.  As we descend the opposite happens with the pressure in the cabin becoming greater than that in the inner ear and the ear drum is pushed inwards.  This affects its ability to move when sound waves hit it and so your hearing become muffled and it might be painful.

The Eustachian is normally closed so to equalise the pressure either side of the ear drum we need to open the tube to allow air in or out.  This action is achieved by swallowing, hence the advice to suck on a sweet, or by yawning which moves the jaw allowing the tube to open.  Holding your nose and blowing forces air up the tube, achieving the same result by a slight less natural route.

Did you know that the back of your throat was connected to your ears?  Does it help explain why some people get ear infections when they have a cold or flu?  Anatomy can explain it all.

Love, Lust and naming structures

With Valentine’s Day approaching this post had to be something to do with Love, or lovematters of the heart.  Whilst there is a large window of opportunity for education around the sexual organs – you only have to listen to the popular pod cast “My Dad wrote a porno” to realise there are big holes in some people’s anatomical knowledge of that region, I thought I would go with something a little more romantic (maybe I’ll cover the other angle on Patreon).

The obvious post would have been about the depiction of the heart and how you would struggle to find anything approaching a traditional heart shape, unless you were dissecting a horse. So, I decided to go with something different!

Let’s have a look at adductors and abductors and see if we can find something romantic there.

Ad

Adductors move things towards the midline of the body (they add to the body).  The adductors of the hip bring the thighs towards the midline.  They bring the two legs together.  They used to be known as one muscle group rather than the three we known them as now. Von Hildebrandt referred to this muscle group as custos virginitalis for obvious reasons.

 

AbAbducens come from the Latin Ab, away and Ducere, to lead.  Abductors move things away from the midline of the body.  The abducent nerve gets its name because it supplies the lateral rectus muscle of the eye, which turns the eyeball outwards.  It was once known as musculus amatorius because of its contribution to proving the sidelong glances of lovers

The naming of anatomical structures is a mixing pot of people egos and preconceptions that always provides a story that adds to the richness of the subject.

 

Anatomical terms. Their origin and derivation. Field and Harrison 1947

Greeks Gods and pet peevs

I recently returned from a weekend away standing around on cold concrete in wellies.  I woke on the Monday with the inability to walk – I was diagnosed with tendonitis in the greatest tendon of all – The Achilles tendon (or the calcaneal tendon as we aren’t meant to name structures after people anymore).

So what does this tendon do and why is it named so.

In short, this tendon attaches the two muscles that make up the bulk of your calf to your foot, giving you the ability to walk.  The two muscles in your leg are the Gastrocnemius; named from the Greek muscmeaning the belly of the leg, and the Soleus; named not from the Latin for sole as the muscle does not attach to the sole of the foot but named after the latin Pleuronectes solea, a sort of flat fish that the muscle resembles in shape.  These two muscles give your calf the shape that it is and both insert into the calcaneal tendon which attaches to the calcaneus, which most of you will know as your heel bone.  It is arguably connected to the plantar fascia which runs into the sole of the foot but traditionally these have been viewed as two different structures.

leg

Its possible to develop these muscles in the gym although the simple test as to their strength is somewhat easier to do – can you go up onto tip toe?  You ought to be able to do it on each foot independently.  On Monday I couldn’t get off of the ground on one side.

 

So- Why Achilles?  Your opinion of Achilles will vary depending on whether your source of information is the original Iliad  poem by Homer, the many myths that have achdeveloped afterwards or Hollywood blockbusters.  The most common myth is that he was invincible, made so by his mother dipping him into the river Styx when he was a baby.  She held onto him by his ankle and hence this part of his body was vulnerable.  It was literally his Achilles heel, the term we now use for a weakness that makes someone vulnerable.  Achilles died during the Trojan wars when Paris, one of the Trojan princes shot him in the heel with an arrow. (We need to gloss over the fact that many statues and paintings depict multiple arrows in Achilles at the time of his death and also the fact that Paris started the whole Trojan war when he took Helen of Troy away from her husband, the King of Sparta, after being promised her hand in marriage by Aphrodite after he judged the Godess the winner of a beauty competition between the Greek gods. Greek myths are never simple)

Tendonitis  is inflammation of the tendon- anything ‘itis’ means inflamed.  In this case the Achilles tendon which affected my ability to go up onto my tip toes and also my ability to bend my foot pact 90 degrees, which affects walking.  A week of rest and anti inflammatories and it’s all back to normal.

So – what’s the pet peev?

You see people stretching their calf muscles all the time.  There are two different stretches for the two different muscles.  Pet peev number one – you need to do both of them to stretch out your calf.

sol

The soleus stretch is the one people often miss out.  Both legs are bent but you are stretching the back leg and that is the one the weight should be over.  You bring the knee forward until you can feel a stretch in the back of the ankle and you hold it there.  The heel needs to be down on the ground.  The leg is bent because the two muscles differ as to where they insert.  The soleus inserts into the leg below the knee joint and so you can stretch it with the knee bent.

gastroThe more common stretch that you see people doing is the gastroc stretch.  This is the one where the back leg is straight.  This is because the gastrocnemius actually inserts onto the femur above the knee joint.  If you bend the leg then you release one end of the muscle.

Both stretches should be performed because if you just do the gastroc stretch it may not be stretching the soleus at all – it depends which of your muscles is the tighter.  When you bend the leg for the soleus stretch you take the gastrocnemius out of the picture because you have release one end of the muscle by bending the knee. It should be impossible to feel a stretch in the gastrocnemius with a bent leg.

Pet peev number two – The thing is both of these stretches are for muscles that go down the back of your leg, straight down the back of your ankle and arguably into the sole of your foot. To do the stretches properly :- The Foot Must Be Facing Forwards!

Try it yourself, get up and do a gastrocnemius stretch with your foot facing forwards and then turn your foot outwards.  The stretch completely goes.  Do not go jogging around the park or do your hours exercise class and then stretch off with your foot to the side and think you have stretched out your muscles, because you haven’t!

If you want your calf muscle to help you be invincible then you need to take care of them. Make sure you put your back foot forwards!

Why drinking can make you act like a muppet.

drink

I was going to post this article before Christmas but that seemed a bit too much like ‘being a kill joy’ so having over consumed during the festive period you can now read all about what it did to your body.

 

Drinking is something most people do during the Festive period.  Scientists argue as to why we drink – there is even the suggestion that it is the foundation stone of human civilisation.  To have pubs you have to have agriculture and cooperative working between several group of people and some form of economy.  There is some talk of reward centres in the brain but given the often bad effects of excessive drink, we do not seem to learn as a society and we regularly go out and over indulge.

We should all know that alcohol comes in units, but what is a unit?  In the UK it is 8g (about 10ml) of pure alcohol.  This is the amount of alcohol that your liver can detoxify in 1 hour (yep, alcohol is a toxin and your liver is your own detox unit – you do not need to live on blueberry smoothies for a month).  This equates to one 25ml measure of spirit, a third of a pint of beer and around half of a glass of wine.  If you drink any more than this then you are going to start to feel the effects of alcohol.

Alcohol can be absorbed through any of your mucus membranes (which has led to some very strange fraternity rituals in USA) so its absorption starts as soon as it enters your champagnemouth. Fizzy things gets absorbed quicker which explains why Champagne and Prosecco can go straight to your head.  It continues to be absorbed through your stomach but most will be absorbed in your small intestine.  Once in your blood stream you can start to feel the effects.

What are those effects?

The first one is you begin to feel relaxed.

This is because alcohol binds to GABA receptors.  GABA (Gamma Amino Butyric Acid) is a neurotransmitter in your brain.  Its exact role is complicated but it increases the amount of dopamine and serotonin in your system.  By binding to the same receptors, alcohol has the same effect; you feel relaxed and maybe sleepy.

Once in your brain, alcohol can also start to effect the feedback with your prefrontal cortex, the part of your brain that deals with analysing future consequences.  Your inhibitions disappear and you are more likely to partake in activities that you wouldn’t consider if you were sober.  Continue to drink and it can start to effect your cerebellum.  This ‘little brain’ at the back of your head is responsible for coordination.  You start to stumble around and you have to adopt a shuffling wide legged stance to enable you to walk.

The second effect is your need to pee.

Often put down to the volume that you are drinking, this is not the case.  How much you need to pee is controlled by a chemical called vasopressin.  This is an antidiuretic and works with your kidneys (another detox organ) to regulate the production of urine.  Alcohol switches off the production of vasopressin and therefore you need to pee all the time.

The last effect is the hangover.

No one is 100% sure what causes the hangover.  There was some belief that it was an imbalance of electrolytes but studies have shown similar levels in those with and without hangovers.  There is some belief that it is some residue in the drink and the higher quality the drink you consume the better you will feel afterwards.  There is some belief that certain combinations of drink can produce more of a hangover than others i.e.’don’t mix grain and vine’.  Its probably due to dehydration.  you just need to rehydrate.  You can’t sweat it out by going for a run, raw eggs have no effect, although, as a resident of Scotland I do have to say I have seen Irn Bru perform wonders.

The fact is that alcohol is a toxin and you need to be aware of that when you introduce it into your body.  1 in 3 men, and 1 in 6 women will develop a health issue that is related to drink.

You need to decide if you want to drink it or not.  Cheers.

cheers