Cranial Nerves Flashcards
What are the purely sensory cranial nerves?
Olfactory, optic, vestibulocochlear
What are the purely motor cranial nerves?
Oculomotor, trochlear, aducens, accessory spinal, hypoglossal
What are the cranial nerves with mixed modalities?
Trigeminal, facial, golssopharyngeal, vagus
Where do cranial nerves provide motor and sensory innervation?
The head (exception is vagus nerve)
Where do the cranial nerves exit the cranial vault?
All exit anteriorly, except CN IV which exits posteriorly and CN VIII which exits laterally
What is each sensory or motor component associated with?
A streak of grey matter in the brain/brainstem which serves on function
What are motor components associated with?
Motor nuclei = groups of efferent nerve cells that send their axons into the cranial nerve
What are sensory components associated with?
Sensory nuclei = groups of nerve cells upon the sensory neurons of the cranial nerves synapse
Where are the soma of sensory nerve cells found?
In ganglia outside of the CNS
What is the only sensory modality that doesn’t synapse in the thalamus prior to reaching the cotex?
Olfactory nerve
Where is the nuclei origin of motor cranial nerves?
Near the midline = all emerge close to midline which reflect location of their nucleus
What are some features of the oculomotor nerve?
Somatic motor and parasympathetic
Relates to Edinger-Westphal and oculomotor nucleus
What muscles does the oculomotor nerve supply with sympathetic fibres?
Sphincter pupillae and ciliary muscles
What are some features of the trochlear nerve?
Somatic motor
Crosses midline
Nucleus in lower midbrain
What are some features of the abducens nerve?
Somatic motor
Located in the caudal pons
What are some features of the hypoglossal nerve?
Somatic motor
Located in the medulla
Where does the spinal accessory nerve originate?
From the cervical spinal cord
What are the functions of the trigeminal nerve?
Somatosensation of face
Proprioception associated with chewing
Motor = muscles of mastication, tensor tympani, mylohyoid, anterior belly of digastric, tensor veli palatini