The Real Anatomist

Ep. 6 Introduction to the human skeleton.

• Alison Craig, Dr David Robson. • Season 1 • Episode 6

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Skeleton

In this episode The Real Anatomist, Dr David Robson, introduces  the human skeleton in his inimitable way.

Discussing the development of our bones, the fascinating history of us, the developing human form, the Romans, the Greeks, referring back to the 1st Century when some of the parts of the skeleton were named. 

And absolutely fascinating facts...eg did you know 96k miles of arteries in the human body? 

There is some comparative anatomy. 

General conversation about the topic, including when a child is growing should they be protected against damaging these developing bones. 

If you have any questions or comments, do can get in touch with Dr David and we can answer personally or answer on next months podcast which will be released on 1st December. The 


 Thanks for listening.


Dr David Robson and Alison Craig

Dr David Robson is a practicing Anatomist who lives and works in Edinburgh.

Click here to contact Dr David Robson directly





SPEAKER_02:

You're listening to the Real Anatomist podcast with myself Alison Craig and Dr. David Robson M D M A who is The Real Anatomist. If you like the podcast, please subscribe and share. Thanks. Well welcome along to The Real Anatomist with myself Alison Craig in conversation with Dr. David Robson, MDMA, and uh a practicing anatomist living in Edinburgh, Scotland. Thank you to everybody that's been listening to the podcast and the feedback we've been having's been great, hasn't it?

SPEAKER_00:

It has. Yeah, so it has. It surely days.

SPEAKER_02:

Yeah, very early days. Last month we finished by giving a little taster of which I know is a massive part of this whole topic, which is of course the human skeleton. And so we are going to be covering that today. Not all of it, obviously, but making a start. And uh also I think I'd like to ask you about your mentor as well this month, Dr. Barlow. So um yeah, let's crack on. Too many questions, and I'm sure some more astounding facts. So thanks for listening to The Real Anatomist with myself, Alison Craig, and David. Okay, let's start with the skeleton. Let's start with the skeleton.

SPEAKER_00:

As you mentioned, the last time the human skull consists of 206 independent bones, 308 in a newborn baby. The human skeleton in itself is an inert frame. It's a series of independent levers of which the muscles can act on to put the body into different positions. It also acts as a protection mechanism for essential organs like the brain, which is encased within the skull, the spinal cord, which is encased within the neural canal of the vertebral column. The heart and lungs are protected within inside the thoracic cage, composed of the thoracic vertebrae, the ribs, laterally and the sternum anterior. Because it's an inner frame, it actually the long bones have a central canal which contains the mouth, which is where you get red blood cells. And the skeleton also acts as a reservoir for certain minerals, particularly calcium. To go through all of the skeleton itself is a big topic. So I'll do it in a way that hopefully you will understand. The skeleton itself is actually divided up into two parts an axial skeleton and an appendicular part. The axial skeleton consists of the skull, vertical column, ribs, sternum. The appendicular part of the skeleton consists of the bones of the limbs, the upper limb and the lower limb and the pelvis. So if we take the axial skeleton first and we look at the bones of the head in particular, there are 29 bones altogether on the head.

SPEAKER_02:

Does that include the neck or is this just the No, this is just the skull, this is just the head.

SPEAKER_00:

So that the and the skull itself consists of eight skulls which form the cranium or the calvarum, which is the top of the skull. Eight bones. Fourteen bones form the bones of the face. Then you have six ossicles. These are the very small bones found in the ear. And you have the mandible and the hyoid bone. The smallest bone in the human body is the stapes. It's two millimeters long.

SPEAKER_02:

Where's that? In the ear.

SPEAKER_00:

It's one of the three ossicles in the ear. And the three ossicles in the ear are the malleus, the incus, and the stepes. Hammer, anvil, and stirrup. To give them the name. And stirp, because when you look at them, the stepes represents that of a stirrup. The malleus is the hammer. And the incus is the anvil.

SPEAKER_02:

So it's a nice way for people to remember the.

SPEAKER_00:

A nice way to remember the three small bones within the ear.

SPEAKER_02:

Because last week, last month, we touched on the clavicle. And you said that was called the clavicle because turned on its side.

SPEAKER_00:

It presents a woman key. It's derived from the Latin clavis, which means key.

SPEAKER_02:

Who developed the names?

SPEAKER_00:

The names of the of the human skeleton is debatable. We don't really fully understand who give the names to the bones. We know that a physician called Rufus of Ephesus.

SPEAKER_02:

Easy for you to see.

SPEAKER_00:

Yeah. In the first century, he gave the names to certain bones.

SPEAKER_02:

Did you say the first century?

SPEAKER_00:

Yes.

SPEAKER_02:

Yeah. I like to just clarify that because sometimes I think that I must have been.

SPEAKER_00:

And a chap that we've already mentioned in the previous podcast called Claudius Galen. He described and named the sacrum and the coccycks.

SPEAKER_02:

When was he around?

SPEAKER_00:

First century.

SPEAKER_02:

He was the first century. Remarkable.

SPEAKER_00:

So But a lot of names for the bones of the skeleton are derived from Latin.

SPEAKER_01:

Right.

SPEAKER_00:

Ancient Greek. And the names really haven't changed at all. If you go to the next part of the axis column, which is the vertebral. The vertebral columns consists of 33 bones. 24 are movable. That's nine are fused.

SPEAKER_02:

And Suleman like myself, is that your back, your spine?

SPEAKER_00:

Yeah, it's just spine, vertebral column. So you have seven cervical, twelfth thoracic, five lumbar, five circular, which is fused to form one triangular-shaped bone, and four coccyle, which forms the rudimentary tail bone. The true vertebral column are the movable ones. Okay. Alright? And that's 24. The uppermost one is called the atlas. And the atlas is unusual. It's actually named after the mythological Titan, an atlas, who held the world above his shoulders. And that's where it gets its name from.

SPEAKER_01:

Okay.

SPEAKER_00:

The other thing that makes it unusual is that the atlas has no body. It's just doing a bone.

SPEAKER_01:

Right.

SPEAKER_00:

But it has no body. The body for the atlas is the upper projection of the second cervical vertebrae called the axis. And the upper projection is called the odonti process. That is the body for the atlas.

SPEAKER_02:

So when they're talking about the atlas being the thing that's supporting the head being the support, it's actually so in the skeleton and anatomy, the atlas is supporting the skull.

SPEAKER_00:

And the only movement permitted between the atlas and the the occipacondyles of the skull is nodding. You can only nod. It's the only movement that takes place. The movement between the atlas and the axis is rotation. The atlas rotates around your dontite process.

SPEAKER_02:

It's really interesting how these words ping up in your brain. When you say atlas, you realize that's been called that for centuries and centuries.

SPEAKER_00:

But then when they find out way back to Greek mythological times.

SPEAKER_02:

And then when they find out that the world wasn't flat, it was round. And that becomes the ball, it becomes the sphere.

SPEAKER_00:

Now you can understand why it's called the atlas, because it's actually supporting the skull. Seven true ribs attached to the sternum. Three false and two floaters.

SPEAKER_02:

Yeah, what's that? I mean that is that a design fault or what's the point?

SPEAKER_00:

No, no, it's it's just how the body is designed. The seven true ribs attached to the sternum. The three false ones attached to the cartilage directly above each one. And the f the floaters attached to the muscles of the abdominal wall.

SPEAKER_02:

Right.

SPEAKER_00:

And they're called the floaters.

SPEAKER_02:

But they are attached. Are they attached to the bones?

SPEAKER_00:

Yeah, but they're not attached to the bone, they're called floaters. So they don't they don't have a uh an attachment to cartilage.

SPEAKER_02:

Last week last month, we talked about these bones in the back of the neck, and you said that the human skeleton has seven cervical vertebrae. And I told several people, I asked them the question, I said, you know, a giraffe's neck. I said, you know, I explained. Do you know just a couple of friends because I found I found it absolutely astounding. Said to a few friends, right, we've got seven cervical vertebrates. I probably didn't call them that, I was trying to, but and I said, How many do you think a giraffe's got? And everybody said 120 or 82 or you know, a ludicrously high number because but just remind us of the seven seven, yeah.

SPEAKER_00:

There were seven cervicular vertebrates in a giraffe.

SPEAKER_02:

So is that the same in all animals? I mean no. Right.

SPEAKER_00:

No. Some animals have more, some have less.

SPEAKER_02:

Because the comparative anatomy is a fascinating part of the subject as well.

SPEAKER_00:

Yeah, because you bring it in to help to understand human anatomy, particularly where the organs are not concerned or the muscles are concerned. But yeah, and in the giraffe, there's definitely only seven. But they're much bigger than ours. But only seven.

SPEAKER_02:

And uh you started off by saying that we have two hundred and six bones.

SPEAKER_00:

Um that's what we end up with. Yeah. That's the normal arrangement. But I'll just finish off doing the appendicular skeleton first, and that means we've done the axial skeleton and then I'll talk about. The appendicular skeleton consists of the pelvic girdle. Oh, going back to the axial skeleton, you also have the shoulder girdle, and that comprises the clavicle. Latin clavus, meaning turn it up and a key or the scapula, or the shoulder blade. And then you have the femur in the thigh, the lower leg consists of the tibia and the fibula, and then you end up with the foot. The number of bones in the foot is 26, the number of bones in the hand, which we didn't mention for the appendicular scan, is 27. There's one more in the hand than there is in the foot. Put all of those numbers together, you'll get 206 bones.

SPEAKER_02:

And if our this is again potentially a dark question, but if our twos were longer.

SPEAKER_00:

Some people do have long tools.

SPEAKER_02:

Could we use them the way that we use our hands or fingers? No.

unknown:

No.

SPEAKER_00:

But if you watch it an orangutan, they have long digits. And the anatomy of the hand is the same as the foot, or the foot is the same as the hand. The only difference is we can oppose with a thumb and little finger, but we can't oppose the great toe and a little toe. But you can in an anthropoid ape. And the old world monkeys you can. And an orangutan can, but we can't. The number of bones that a child has or a baby has is 308, which These are separate bones, these are called epiphyses because the head of the femur is separate, the gratitude can't have the femur is separate. So during development, they start to migrate together in the fuse. And that's how the number is reduced from 308 to 206.

SPEAKER_02:

And at what age do these bones are they set the way as an adult?

SPEAKER_00:

As an adult, by the time you're 25, all the bones are fully set.

SPEAKER_02:

What struck me about that was the amount of physical exercise that kids have naturally, they're all running around, you know, and certainly climbing trees and leaping around. Um and of course they get broken bones and and whatnot. But some of the more extreme training, for instance, a child might go through if it's perhaps going to be identified as a potential you know, rugby player or a football player or a gymnast, are are they not damaging their development and the the the coming together of these bones by training and playing away?

SPEAKER_00:

And yes, but if you had to take a long bone, you have the shaft which is the diaphysis. And at each end you have the grown ends of the bone, and that's the epiphyses, and it's the grown ends that are responsible for the length of the bone by telling the bone is fully developed. And that's the epiphyses. And they're separate during development, and then they fuse with the shaft. So yeah, if you're doing an intense sport training, there's always the possibility that you can damage the bones by fractures and that.

SPEAKER_01:

Oh yes.

SPEAKER_00:

And the strongest bone in the human body is the femur.

SPEAKER_02:

Which is the thigh bone.

SPEAKER_00:

And its other name is the os femoris. That's its other name. The interesting thing about the tibia and the fibula and the lower leg is the tibia is known as the flute because it represents the wind instrument. And if you look at the fibula, that is derived from the Latin word for brooch because it represents a Roman brooch. Because of its shape. Because it's this the fibula is not just a straight bone, it actually slightly spirals around. So yeah, you get different names for different bones if you go back to it in history.

SPEAKER_02:

Yeah, so these names were given, it just shows you how incredibly sophisticated the Romans were. Oh the Romans were, so were the Greeks.

SPEAKER_00:

Flutes and brooches. But they were, you see, because it the tibia represents this flute, this musical instrument, because it's hollow. And it's and the shaft of the long bone is just hollow, and in there you have the bone marrow. And in the bone marrow, that's where your red blood cells are being produced.

SPEAKER_02:

So if you were a father of a 14-year-old boy, let's just this is a random, probably using this as an example because my son played a lot of rugby when he was that kind of age. Um that crashing they do into each other and you know, tackling and all that, and footballs, you know, it's all quite rough and tumble, obviously. It's been discouraging uh, you know, your child's it's difficult.

SPEAKER_00:

Yeah. It's very difficult to stop children from playing a sport. But it's it's changing because football, they're now trying to restrict the heading of the ball because there's a direct link now between that and dementia. Yeah. The same with the same the same with sport. Contact. Contact sport, particularly in rugby, especially the scrum because the heads are getting banged together.

SPEAKER_01:

Yeah.

SPEAKER_00:

So you have to be careful.

SPEAKER_01:

Yeah.

SPEAKER_00:

And then of course you have the more serious side of it all, particularly in rugby, where some players unfortunately end up with a broken neck.

unknown:

Yeah.

SPEAKER_01:

You can become paralyzed from the neck down.

SPEAKER_00:

Yeah. Yeah. And like in some, there's an instance last week where Fram, the cyclist, he was in a horrendous accident and had to have emergency surgery because he fractured one of his lumbar vertebrae. That requires surgery. If if you're young and you're doing your sport and you're very careful, you're okay. It's the amount of sport that you do during your life. Unfortunately, you think, oh, it's all great, but unfortunately it comes back to haunt you when you get older. I was gonna ask. Because people tend to develop arthritis because of the damage to the joints.

SPEAKER_02:

Okay, and so that's what arthritis is, isn't it?

SPEAKER_00:

Well it's arthritis is considered as wear and tear. Yeah. If you take, and again it's a controversial subject because of arthritis, but if you take the bones of the human skeleton, you just take one, take one bone, just take the feminine. The bones are covered in a protective membrane, covered by perosterum. And the best way to describe this is to think of getting a piece of cling filament and wrapping your salmage or your cucumber up in cling filament, it's protecting the food. It's the same principle for the perostum, protecting the bone. So if you get a compound fraction and the bone shoots through the skin, it's a compound fracture, it'll tear the peroster. And that perosterum is important because it's helping to protect the bones. And all bones in the skeleton are called in periosterum. So what happens is when I say wear and test it's because we're overshooting my hands or my knees, whatever arteries that we're doing, over a long period of time it's going to rub away.

SPEAKER_02:

Anyway, no matter what you do.

SPEAKER_00:

Yeah, it doesn't matter basically. What happens then is that because that periostum has been rubbed away, the surface of bones will come into contact. And it's that friction, that rubbing, that starts for osteoarthritis. And you can see that if you look at skeletons that have been dug up in archaeological sites. Of osteoarthritis, particularly. And the swelling, but not the bones.

SPEAKER_02:

And is there anything people can do to help that or to prevent it to try to do that?

SPEAKER_00:

You can't, not really like you know the overseer will just have a good sense of diet, have your your greens, your vegetables, you know, drink your water and that. But it depends on the type of job that you're doing.

SPEAKER_02:

Yeah, of course, yeah.

SPEAKER_00:

It's like it's like it's like writers, artists that are constantly writing all the time. The hands are in a particular position like that for writing. See the way I've got the fingers? Yeah, turning like that. But what can happen is the person slowly over a long period of time, the little finger in the ring finger will start to curl in. And that's called a Dupatron's contraction. It's where the fibre sheath curving the tendons tightens up and the tendons become involved, and you get a Dupatron's contraction. It's a simple operation, you make an incision and you release it. Named after a French surgeon called Baron Georges Dropatron. First amongst surgeons, last amongst men. He had a terrible reputation. But when he died, he left his money to endow a chair of pathological anatomy and pathology.

SPEAKER_02:

So he came good in the end. He came good in the end. Literally in the end when he died.

SPEAKER_00:

So yeah, so the skeleton is fascinating.

SPEAKER_02:

It is, I mean, it's a lot to sort of take in. So what I'm going to do, if you're not going to be able to do that.

SPEAKER_00:

But it is because if if if if we mentioned the hands, the 27 bones of the hand, divided up into three parts, you have the wrist. And the wrist consists of two bracelets of bones, of which there are eight. Then you have the five metacarpal bones, and then you have the digits made up of the phalanges. Fourteen in total, two for the thumb and three for each finger. Five metacarpals, eight carpis bones. In the foot, it's seven tarsus bones. Five metatarsals, but fourteen phalanges. It's a lot to take in. It's a lot to take in, and then the bones of the carpets have all got the owner and betiscular names. They're collectively known as car carpus. And then you've got different shapes of bones. You have the long bones, which are particularly relevant for the limbs, like the humus in the upper arm. Latin name for that is humerus. Just later on they stuck an H on, that's why it's called the humus.

SPEAKER_02:

Somebody was having a joke.

SPEAKER_00:

And then you have the radius and the ulna, the two for one bones. And then you come down to the wrist and you have the eight carpet bones. And the eight the names of the eight carpet bones are you have the trapezium, the trapezoid, the capitate, the hamate, the pysiform, the scaphoid, and the loneid, and the tricretal. They're the eight bones that make up the carpal bones of the wrist.

SPEAKER_02:

That's just the wrist, yeah.

SPEAKER_00:

That's just the wrist. And then the foot, the seven tosser bones is the tailus, the calcaneum, and the navicular, the major lateral cuneiforms, and the cuboid. And that's the seven.

SPEAKER_02:

There's a lot to learn. And I always like to reiterate this every podcast that you never refer to notes. Everything you talk about is in the mind. Yeah, it's in the mind somewhere. Makes it sound like you're making it up, but it's off the top of your head. It's all off the top of your head. Yeah, which is which is remarkable.

SPEAKER_00:

And then so and then you show that long bones, the bones of the wrist, or short bones. Right. Because in a confined space. So they're there for strength. Flap bones consist of the scapula for muscular touchings, flat bones for the skull, particularly for the calvaum of the cranium. You have irregular shape bones. These are bones pertaining to the vertebral column, because they are regular shaped. And the second, because it's a triangular red shape bone. Then you have funny little bones, other names for bones, called pneumatic bones. In the skull, and they're actually the two tables of the skull bones. And the substance in between is the diploe. And one of through them is veins, which we'll discuss later on in the podcast. But as the bones are developing in that that actually changes. And you end up with sinuses in the bones. Like the Maxov sinus on the face, or the frontal sinus of the brow. And the mastoid sinus. Yeah, these are air sinuses. They contain air.

SPEAKER_02:

And are we born with them?

SPEAKER_00:

Oh yeah, yeah. But they're there, they just develop. And the bones that are related to them are known as pneumatic bones. And then you have other bones, extra little bones, called Wormion bones. W-O-M-I-A-N, named after Olaf Wormian, the anatomist who first described them in the 1600s. And these are tiny little bones in relationship to the sutures. If you look at the skull, it has sutures, particularly the lamboid suture at the back between the parietal bones and the occipital bone. You'll have these little bones, and they're called warmion bones. Wormion bones, and then you have another little set of bones, which aren't really in the series of the main skeleton. And these these ones are called epiteric bones. These are like scale-leg bones, tiny little scale-leg bones, which are always associated with the anterolateral sinus. Of the skull. It's not sinus fontanelle. And on the school you have the anterior frontanelle between the two frontal bones and the front. It's very soft, yeah, it's triangular shape, and the last one to close is the anterior frontanelle, closes by the age of two. And they're important, particularly the anterior fontanelle. Because if you needed to get it an antibiotic in fast into a newborn baby, you could actually put it in through the anti frontanelle straight into the superior venous satural sinus. Yeah, yeah, you can get in quick.

SPEAKER_02:

Yeah.

SPEAKER_00:

So they're different classes of bones as opposed to the main bones that we've just described.

SPEAKER_02:

But they're all categorized as bones. Oh yes, okay from the top to the tube, literally. Yeah.

SPEAKER_00:

The way they say that the scale-like bones is because the vision we developed from the fish.

SPEAKER_02:

Yes. So what is the resemblance between a scale-like bone and a fish?

SPEAKER_00:

Well, if you look at the fish, fish all have scales. Yes. They're very fine, different shapes. It's the same principle for these epiteric bones on this on the human skull. So they're tiny. They're not always there, they're they're rare, but occasionally you will you'll come across them.

SPEAKER_02:

They're not always there. No.

SPEAKER_00:

No, because the the anterior lateral fontanelle at the front isn't always present. The anterior one is and the posterior one is. But again, with the posterior fontanelle, sometimes that can be missing as well.

SPEAKER_02:

So at the at this point in our evolution, these little bones are they don't have a purpose then, or they're just fading out from our development.

SPEAKER_00:

But if if you have them at the anterior lateral fontanelle, instead of that being soft, you have this little scale like bone filling in the gap.

SPEAKER_02:

Which must be, as an anatomist, a fascinating thing to see.

SPEAKER_00:

It is.

SPEAKER_02:

So I mean, if you say something a bit further back down the food chain, which I think I've used that expression about some of the boyfriends I had when I was younger, that could actually be the case.

SPEAKER_00:

Well, that's a different story.

SPEAKER_01:

Wow.

SPEAKER_00:

So that's giving an introduction to the human skeleton.

SPEAKER_02:

Yeah.

SPEAKER_00:

The normative arrangement is in the adult skeleton of 206 bonds. But nature decides sometimes to put a span on the works.

SPEAKER_01:

Right.

SPEAKER_00:

And maybe it. Or two may be fused. Or nature may give you an extra rib in the neck, called a cervical rib.

SPEAKER_02:

In the neck.

SPEAKER_00:

In the neck, yeah. Yeah, but it takes a torsion from the transverse process of the seventh cervical vertebra, which has the longest spine of the cervical vertebra and is known as the vertebrae prominence. And that can be a cervical rib, and it can be unilateral or bilateral, meaning it can be on one side or on both sides.

SPEAKER_02:

So as a you know work person walking around that knows nothing about the anatomy, let's just say me, because that would be the case. But if I have a sore back or a sore neck, you know, and I go to you know the doctor and say I've got a sore back or a sore neck, they're not going to take into account any of these potential anomalies.

SPEAKER_00:

No, no, you're only sure when if an x-ray is taken.

unknown:

Right.

SPEAKER_00:

You know, if you've got if a person goes to vegetables rib, then they can cause a nerve of vascular problem with the upper arm. Right. Because it depends on the development of it. And then nature throws another span in the works and we will have about twelve ribs. From time to time, nature will chuck another rib in and it'll be known as a lumbar rib.

SPEAKER_02:

Right.

SPEAKER_00:

And that arises from the first lumbar vertebrae.

SPEAKER_02:

Gosh. And could you tell that if you put your hands on a patient that they've got that extra rib?

SPEAKER_00:

Yeah, but it's very rare that one.

SPEAKER_02:

Very rare.

SPEAKER_00:

That one's very rare.

SPEAKER_02:

Have you come across it?

SPEAKER_00:

Once.

SPEAKER_02:

Once. Yeah.

SPEAKER_00:

Yeah, so a long time ago, and it was much smaller. But it was a lumbar rib. It came from the transverse processor value one. So you see, you just never know. The plan is everything there. We should have 206 bones, 650 muscles, 96,000 miles of arteries in the in the human body. How many? 96,000 miles. That'll go around the world three times. Yeah, stress. Okay, that'll just just little examples. But then from time to time nature will just change the plant slightly. Nice shaft, nice and smooth, and then from time to time it'll produce a spur. A suprachondylar spur. Always on the inside. And attached to that, that'd be a tiny little ligament going down to the medial epicondyle. The suprachondyle ligament of Struthers. Struthers was a famous surgeon and anatomist who first described it. And sometimes if that's burned, I'll reinforce this in later podcasts. But if this happened, then sometimes the median nerve can come down with a bicular and actually pass through the little space between the ligament and the shaft of the humus, which is unusual. But can be common in animals.

SPEAKER_02:

Particularly the monkeys. Monkeys.

SPEAKER_00:

Yeah.

SPEAKER_02:

We're not that far away, are we?

SPEAKER_00:

And as I've said before, this is what makes the whole subject interest.

SPEAKER_02:

You're listening to the Real Anatomist Podcast with myself, Alison Craig, and Dr. David Robson, M D MA, who is the Real Anatomist. If you like the podcast, please subscribe and share. Thanks.