Cranial nerves III (oculomotor), IV (trochlear), VI (abducens), XI (accessory), and XII (hypoglossal) are motor nerves only.
sensory nerve
There are 12 pairs of cranial nerves that are part of the PNS. These nerves are sensory, mixed and mostly motor.
The cranial nerves have various functions related to sensory, motor, or both. Some cranial nerves are primarily sensory, transmitting information from the senses like taste, smell, and vision to the brain. Others are mainly motor, controlling movements of the face, head, and neck muscles. Some cranial nerves have both sensory and motor functions, allowing for a combination of sensory input and motor control.
The only two cranial nerves that are completely sensory are the olfactory nerve (I) for smell and the optic nerve (II) for vision.
Cranial nerves VII, IX and X are called mixed nerves because they contain both motor and sensory nerves.
There are 12 pairs of cranial nerves, which make a total of 24 cranial nerves. These nerves emerge directly from the brain and are responsible for various sensory, motor, and autonomic functions in the head and neck.
Cranial nerves are primarily sensory. These nerves are directly between the brain and the brainstem and are responsible for smell, vision, eye movement, facial sensation, and the tongue movement.
The question is asking what three cranial nerves are purely sensory in their function. Some relevant terms here are olfactory, optic, and auditory or vestibucochlear or acoustic nerves. The only three cranial nerves that are pure sensory in function are cranial nerve #1 : the olfactory nerve (smell), cranial nerve #2 : the optic nerve (sight), and cranial nerve #8 : the auditory/vestibucochlear/acoustic nerve (hearing).
Somatic sensory nerve impulses from the head travel through the cranial nerves, such as the trigeminal nerve (V), facial nerve (VII), and glossopharyngeal nerve (IX). These nerves carry sensory information to the brainstem, specifically to the trigeminal nerve nuclei, which process and relay the information to higher brain regions for further processing and perception.
Olfactory
There are 12 pairs of cranial nerves, each with specific functions related to sensory, motor, or mixed functions in the head and neck regions.
The Optical nerver or the Second Cranial nerve controls and relays information absorbed through the rods and cones of the eye. Eye movements (eye muscles), however, are controlled by several other cranial nerves including the Oculomotor, Abducens, and Trochlear nerves.