Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them]
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Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] |
[On the Mechanical Engineering Aspects of the Ear]
Since the cartilage of the ear
[cartilago auricularis], when
completely free of the skin that covers it, expresses the shape of the ear
itself with its lobe
[lobulus auricularis]
1
removed, it would be beside the
point here to draw an ear, which is known to everybody.
What the chief purpose of the ear is in taking in the convolutions and
spirals of the air, and what names the parts of the ear are given, must be
pursued in the account of the construction of the organ of hearing in the
seventh book. Here the cartilage of the ear comes momentarily under
consideration. It resembles the shape of the ear and is formed so that when
clothed in skin it will make the body of the ear like a fan and likewise
suitably hold it up and keep it erect. This cartilage
[c. elastica] is soft and thin,
becoming softer as it goes from the bone of the head
[os temporale] toward the end of the
ear and approaches its rounded part
[helix], having less need to support
anything. In the same way, no part of this cartilage is extended in the lobe of
the ear, as there is no need for this suspended part to be held erect or
supported. Near the temporal bone this cartilage feels harder and, so as to
adhere with a firmer root, thicker. It originates from the small circle of the
foramen
[meatus acusticus externus] (a in
fig. 2, ch. 12) of the auditory meatus carved in the temporal bone, whose
circumference is roughened so as to put forth the cartilage more readily. For
what reason Nature made the ear from such cartilage and did not implant in it a
harder, osseous cartilage or actual bone, I explained in the second Chapter of
the present book when I stated that Nature fashioned the blend of the cartilage
with such foresight that it would provide expedient support, like bone, and at
the same time be so soft that it would not be broken by the impact of things
striking it but by gently yielding would relieve the ear, and in this way make
the outermost parts more resistant to injuries than if they had been bony.
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Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] |
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