Question

1 List all of the cranial nerves that only have a purely sensory function & state the specific function of each cranial nerve that you list.

2. Where are the basal nuclei located? What is their general function?

Answer 1

Answer) The cranial nerves are a set of twelve nerves that originate in the brain.

• I. Olfactory nerve
• II. Optic nerve
• III. Oculomotor nerve
• IV. Trochlear nerve
• V. Trigeminal nerve
• VI. Abducens nerve
• VII. Facial nerve
• VIII. Vestibulocochlear nerve
• IX. Glossopharyngeal nerve
• X. Vagus nerve
• XI. Accessory nerve
• XII. Hypoglossal nerve

TYPES -

1. Sensory nerves are involved with your senses, such as smell, hearing, and touch. They contain purely afferent fibres which only brings the signal to brain.
2. Motor nerves control the movement and function of muscles or glands. They contain only efferent fibers and bring the action signal from brain to muscles.
3. Mixed nerves contain both afferent and efferent fibres.

LIST OF ALL SENSORY CRANIAL NERVE -

Cranial nerves I, II, and VIII are considered purely afferent nerves since they conduct sensory information from the olfactory region, the retina of the eye, and the inner ear structures, respectively.

I. Olfactory nerve

The olfactory nerve transmits sensory information to the  brain regarding smells that we encounter.

III. Oculomotor nerve

The oculomotor nerve has two different motor functions: muscle function and pupil response.

• Muscle function. The oculomotor nerve provides motor function to four of the six muscles around the eyes. These muscles help the eyes move and focus on objects.
• Pupil response. It also helps to control the size of the pupil as it responds to light.

VIII. Vestibulocochlear nerve

The vestibulocochlear nerve has sensory functions involving hearing and balance.

ANSWER 2) The basal ganglia are surrounded by a white mass of the cerebral hemisphere, and the individual nuclei that enter into their composition build the walls of the lateral cerebral chambers.

The basal ganglia include:

• corpus striatum
• claustrum
• the amygdala
• substantia nigra
• subthalamic sails

The most prominent functions of the basal ganglia include:

• Acts by modifying ongoing neural activity in motor projections
• Delivers an inhibitory role in motor control
• Inhibits muscle tone (balance of excitatory and inbound input signals according to PMN terminating on skeletal muscle)
• Monitor and adjust slow and continuous contractions (equilibrium, body position, etc.)
• Regulates attention and individual cognitive processes
• Participates in motor planning and learning
• Assisting the cerebral cortex in making subconscious, learned movements