I’m barnstorming the semifinal install and check of all courseware modules, mixing new ones, reprocessed old ones, and unprocessed old ones. As I run through each lesson, I’m reminded again of the remarkable engineering in our anatomy. Time for a break.
Here’s a piece of engineering in the palate and pharynx.
For orientation, this picture compares cat and human and bird, showing the uniqueness of the human pharynx. The human pharynx is a resonant cavity that extends behind the nasal passages and the mouth, with a closed end at the top.
The animation is looking forward from the back of the pharynx, with the POV basically where the vertical word ‘pharynx’ stands in the first picture. The tensor veli palatini does what it says on the tin. It tenses the soft palate, pulling both sides outward to create more stiffness. The tensor muscles pull UPWARD, with tendon pulleys passing through the two hooks to change the pull to OUTWARD.
Those hooks are an extension of the pterygoid (wingy) bone which forms part of the base of the brain. Here’s the wingy bone seen from the top, with the hooks clearly visible at the back:
The hooks and the muscle and the palate itself all had to exist before their function was possible. Without the hooks, those muscles would just clamp the palate upward.
Millions of years later we reinvented the direction-changing pulley as seen in the Sholes typewriter, or more familiarly in a curtain pull cord.
Polistra's Mill 