When the muscles on the posterior side of the head pull on the skull and oppose the tendency of the head to tip anteriorly,one has an example of a _____ lever.
A)first-class
B)second-class
C)third-class

Question

Quizplus · Accepted Answer

This is an example of a first-class lever, where the fulcrum (in this case, the atlanto-occipital joint) is located between the effort (muscles on the posterior side of the head) and the load (the tendency of the head to tip anteriorly).

When the Muscles on the Posterior Side of the Head