The posterior neck muscles function as a class Blank______ lever system.Multiple choice question.312

To determine the correct type of lever system that the posterior neck muscles function as, we first need to understand the classifications of levers in mechanics.

Classifications of Levers

1. Class I Lever: The fulcrum is positioned between the effort and the load. An example is a seesaw.
2. Class II Lever: The load is positioned between the fulcrum and the effort. A common example would be a wheelbarrow.
3. Class III Lever: The effort is applied between the fulcrum and the load. Examples include the biceps in the arm lifting a weight.

Analysis of the Neck Muscles as Lever Systems

• In the case of the posterior neck muscles, they typically act to extend the head and neck, providing the effort to raise the head against the weight of the head (the load).
• The fulcrum in this instance is located at the atlanto-occipital joint, where the skull meets the spine.

Given this arrangement, we can conclude that the posterior neck muscles are functioning as a Class I lever because the fulcrum (atlanto-occipital joint) lies between the effort (force exerted by neck muscles) and the load (the weight of the head).

Final Answer

The posterior neck muscles function as a class I lever system.