Activity 4
Bell's palsy is the paralysis of facial muscles. It occurs because of damage or disease afflicted on the facial (VII) nerve. The patient's case seems severe, as there is drooping on the entire side of his face. Some of his symptoms include the inability to wrinkle his forehead, close his eye, or pucker his lips on the affected (left) side of his face. He may also experience drooling or difficulty swallowing.
Affected muscles include:
Orbicularis oculi
Action: closes eye
Occipitofrontalis (Frontal belly)
Action: Draws scalp anteriorly, raises eyebrows, and wrinkles skin of forehead horizontally as in look of surprise.
Orbicularis Oris
Action: Closes and protrudes lips, as in kissing; compresses lips against teeth; and shapes lips during speech.
Zygomaticus major
Action: Draws angle of mouth superiorly and laterally, as in smiling.
Levator labii superioris
Action: Raises upper lip.
References:
Tortora, G. J., & Derrickson, B. H. (2017). Principles of Anatomy & Physiology. Wiley.