What is the primary sensory function of the trigeminal nerve (CN V)?

The primary sensory function of the trigeminal nerve (CN V) is to provide sensation to the skin of the face and mucous membranes. This nerve is divided into three major branches: the ophthalmic, maxillary, and mandibular nerves, each responsible for transmitting sensory information from specific regions of the face.

The trigeminal nerve detects sensations such as touch, pain, temperature, and proprioception, allowing individuals to perceive and respond to various stimuli on the face and oral cavity. This function is crucial for activities such as eating, speaking, and protecting the face from harmful stimuli.

The other options refer to functions that are associated with different cranial nerves. For example, control of tongue motion is primarily the function of the hypoglossal nerve (CN XII), while providing auditory information is handled by the vestibulocochlear nerve (CN VIII). Regulating heart activity relates to the vagus nerve (CN X), which oversees parasympathetic control of heart rate. These distinctions highlight the specific and unique role of the trigeminal nerve in sensory function.