The Ossicles
Anterior View of the Ossicles
After sketching all the individual bones, here are all three of them together in situ, but what do they do ? These three small bones (the hammer. The Anvil & Stirrup) carry sound waves from the ear drum to the Cochlea and its a nice bit of mechanics.
First of all, sound waves hit the tympanic membrane (AKA as the Ear Drum) , the vibrations are then carried through the Malleus, Incus and finally the stapes which then takes these vibrations to the inner ear. They effectively act as a lever and give a mechanical advantage, by not just the lever effect, but also my reducing the area of force. If the sound waves went direct from the ear drum to the inner ear, they would be a lot weaker – Its a nice bit of design.
There are also muscles attached to the ossicles which can control the extent of movement which is believed to protect the inner ear from loud noises. Interestingly in Bats, these muscles are highly developed and seem to be crucial in their sonar and echolocation senses.
So there you have it ladies and gentlemen, the Ossicles. As for the drawing itself, I’m not too happy with it. Not just because I used my old pad after the luxury of using the heavier a5 pad, but because after mentioning last week about looking at other areas when it comes to shading, I started all guns in on the Malleus with a 6B which didn’t really give us much room for shading darker areas afterwards. Thankfully the HB came to the rescue on the Tymponic cavity, but my original intention was to have that darker and the ossicles lighter.
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Categories: Human Anatomy Tags: 6B, Anatomy, Bones, Ear, HB, Head, Incus, Malleus, Middle Ear, Ossicles, Skull, Stapes, tympanic membrane
Ossicles – Stapes
The Stapes
Onto the smallest bones of the human body the Ossicles and for this post the Stapes (AKA Stirrup bone) which amongst other things is another fine case of what I mentioned in my post about curves. It is also something I imagine wouldn’t be out of place in a Yves Tanguy painting.
To give you an idea of how small this bone is, there is an excellent image in the wikimedia commons
The size did present some problems when drawing it, noticeably most of the images I could find were … well , small and what large diagrams I could find, didn’t really give any indication of texture or detail. It also seems that not all stapes are born equal , which you can see if you do a quick google search on the term.
Most confusingly, which I could not find an explanation for; some pictures seem to show a horn on the head as in mine and others don’t. It was also hard to find close up detail of the neck and head section.
My drawing is a hybrid of the photographs and diagrams I came across , I think this has had an effect on my shading in terms of representing light as I had no real reference.
Rest of the Ossicles coming soon….
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Categories: Human Anatomy Tags: Anatomy, Bones, Ear, Head, Middle Ear, Ossicles, Skull, Stapes, Yves Tanguy
