AEMCA Practice Exam

What function does cranial nerve 7 serve?

1. Regulates balance and hearing

2. Activates muscles of the face for expressions

3. Controls blood pressure and swallowing

4. Stimulates gastric motility

The correct answer is: Activates muscles of the face for expressions

Cranial nerve 7, also known as the facial nerve, is primarily responsible for the activation of muscles involved in facial expressions. This nerve controls various facial movements such as smiling, frowning, and other expressions. Additionally, it has some sensory functions, including taste sensations from the anterior two-thirds of the tongue, and it also innervates some glands such as the salivary and lacrimal glands. Understanding the roles of cranial nerves is crucial for comprehending the nervous system's organization and function. The other options listed show distinct functions associated with different cranial nerves or systems. For instance, balance and hearing are primarily associated with cranial nerve 8 (the vestibulocochlear nerve). Blood pressure regulation and swallowing involve multiple nerves, notably cranial nerves 9 and 10 (the glossopharyngeal and vagus nerves, respectively), while gastric motility is controlled by the autonomic nervous system and mainly involves cranial nerve 10 as well. Therefore, activating facial muscles is the accurate and defining role of cranial nerve 7.