Hello friends! As I discussed in my last blog post, I have decided to take a look at the physics that goes on inside our very own bodies! This post will focus on the physics behind the movement of our bodies, mainly involving the muscular system.
The muscular system works in close conjunction with the nervous system, which I looked at last time. Neurons transmit their impulses to the muscular system in order for the body to move in the way the brain intended it to. Muscles are made up of myofibrils, which are the smallest muscle fiber. Muscles are attached to the bone by tendons, and this attachment is what enables the muscles to move the bones of the body.
When muscles contract, they create a force on the bone they are attached to, doing work in order to the control and move the bone the way the neurotransmission intended it to. Just like all objects in motion, the human body follows Newton's 2nd Law: the human body's rate of change of momentum is proportional to whatever force is applied to it: in this case, the muscles applying force on the bones.
Since most body movement happens in the joints, which function as hinges and levers, much of the body's movement is angular movement. Torque is a property of anatomical movement often times investigated. Torque is often observed in the upper and lower parts of the arm surrounding the elbow, since it is such a common rotational joint:
Joints act as machines which help the body to perform work more efficiently. Could you imagine walking around with absolutely no joints? A lot of motion would become incredibly difficult! Our joints act as levers by establishing a fulcrum point (again using the elbow as an example). The elbow itself is the fulcrum, and when a load is placed in the hand, the work done by the bicep is made significantly less than if done without the use of such a fulcrum point. Joints not only help with burdens placed by external loads... We can't forget what a heavy burden good ol' gravity can be on our bodies!
Basically, without physics, humans would be completely bed ridden with no motion at all... which would make for quite the boring day. Even the human body has immense connections to physics!
Until next time, Fizzix Community, until next time.