Use a mirror to frown or wrinkle your forehead to observe the epicranius muscle . Observe the orbicularis oculi (closes the eye) and orbicularis oris (closes the mouth). 2. Muscles of the Neck
Locate this muscle on the front surface of the neck. Use a mirror to frown or wrinkle your
Observation: When turning the head, the left and right muscles act as . However, when they contract simultaneously, they act as synergists to pull the head forward or downward. 3. Muscles of the Trunk when they contract simultaneously
Place your hands on your temples and perform chewing movements. Feel the tension in the temporal muscle as it raises the lower jaw. Locate the masseter muscle near the jaw joints. Use a mirror to frown or wrinkle your