Week 8 – Cancelled Excursion, and the Motor System

This week the course was scheduled to have an excursion, but this was cancelled last minute! I was looking forward to it, so this is a shame, hopefully the future ones are completed as planned!

The lecture of this week was about the motor system, which of course is responsible for the movements created and maintained by muscles all over our bodies. Trough nerve connections, which connect from the brain along the spine, the brain can send signals for whichever action, and the muscles send signals back to the brain, which allows for the conscious feedback and motion which we’re all familiar with. I’m interested in what effects the accuracy of this, which varies from person to person as well as what causes diseases associated with motion loss or weakening.

When a muscle receives a signal, triggered by action potential, it contracts and tightens. The amount it tightens can vary, and functions trough muscle fiber. Trough combinatorics, or having multiple muscles for the same area, specific precise movements are possible! Most notably, our hands having 18 intrinsic muscles is what makes them so adaptable and precise! Or another example is our face, which has a whopping 43 muscles, and is thus capable of such a wide range of emotions and actions. The tightening of specific facial muscles is strongly and instinctly related to emotion. In fact, there is a feedback loop, the act of learning which muscles are associated with which emotion, and consciously straining that muscle evokes the emotion it is linked to!

Some of the facial muscles are showcased above!