Question

Know and describe the cranial nerves (I - XII) with respect to to their distribution in terms of their

i) general sensory,
ii) special sensory,
iii) motor (somatic or brachial) and
iv) parasympathetic (visceral motor) functions?

Answer 1

The twelve cranial nerves have different functions, including special sensory, general sensory, motor, and parasympathetic responses. Olfactory (I), optic (II), and vestibulocochlear (VIII) are purely sensory; oculomotor (III), trochlear (IV), abducens (VI), spinal accessory (XI), and hypoglossal (XII) are primarily motor; while trigeminal (V), facial (VII), glossopharyngeal (IX), and vagus (X) are mixed nerves with both sensory and motor components.

Step-by-step explanation:

Cranial Nerves Overview

The twelve cranial nerves are essential for the sensory and motor functions of the head and neck, with the vagus nerve additionally serving the thoracic and upper abdominal cavities. Cranial nerves I (olfactory), II (optic), and VIII (vestibulocochlear) specialize in special sensory functions like smell, vision, equilibrium, and hearing. Cranial nerves III (oculomotor), IV (trochlear), and VI (abducens) are primarily motor, controlling eye movements. Cranial nerves V (trigeminal), VII (facial), IX (glossopharyngeal), and X (vagus) are mixed nerves, involving both sensory and motor components. Lastly, XI (spinal accessory) and XII (hypoglossal) are strictly motor nerves.

Sensory cranial nerves contribute to general and special senses, while motor cranial nerves facilitate muscle movements. Four cranial nerves also have parasympathetic responsibilities, controlling bodily functions such as pupillary response and saliva secretion. Spinal nerves, on the other hand, are mixed; organizing into plexuses and managing various bodily sensations and movements.