Cranial Nerves and Nuclei Flashcards
Describe the olfactory pathway?
1) There are receptor cells in the olfactory epithelium
2) These pass up through the cribriform plate of the ethmoid
3) These synapse in the olfactory bulb (visible on inferior aspect of the brain)
4) The neurons pass along the olfactory tract
5) The olfactory cortex which processes the smell is plugged directly into the olfactory tract
note this is only nerve that does this the rest have to plug into the cortex first
What modality does the olfactory nerve have?
Special sensory
What nucleus does the motor fibres for the oculomotor nerve originate in?
The oculomotor nucleus
What nucleus do the preganglionic parasympathetic neurones from the oculomotor nerve originate in?
The Edinger Westphal nucleus
What originates in the Edinger-Westphal nucleus?
preganglionic parasympathetic neurones from the oculomotor nerve
What originates in the oculomotor nucleus ?
Motor fibres for the oculomotor nerve
Where is the oculomotor nucleus located?
In the rostral midbrain
Where are do the motor fibres for the trochlear nerve originate?
In the trochlear nucleus
The fibres of the trochlear nerve _______ so _____
exit posteriorly and cross sides so the right nerve supplies the left eye and vice versa
What originates in the trochlear nucleus?
Motor fibres for the trochlear nerve
Where do the motor fibres for the abducent nerve originate?
in the abducens nucleus
Where is the abducens nucleus located?
In the Pons below the 4th ventricle
What originates in the abducens nucleus?
Motor fibres for the abducent nerve
Where do motor fibres for the hypoglossal nerve originate?
In the hypoglossal nucleus
What originates in the hypoglossal nucleus?
Motor fibres for the hypoglossal nerve
Where does the spinal accessory nerve originate?
In the accessory nucleus
Where is the accessory nucleus?
In the cervical spinal cord
What originates from the accessory nucleus?
The motor fibres for the spinal accessory nerve
What nuclei contribute to the trigeminal nerve?
Mesencephalic nucleus
Pontine trigeminal nucleus
Spinal trigeminal nucleus
Trigeminal motor nucleus
What fibres does mesencephalic nucleus provide?
Sensory
proprioreception from chewing for the trigeminal nerve
What fibres does the pontine trigeminal nucleus provide?
sensory
discriminative touch, vibration for the trigeminal nerve
What fibres does the spinal trigeminal nucleus provide?
Pain and temperature
for the trigeminal nerve
(also small amount of somatosensation to the ear for vagus, glossopharyngeal and facial and vagus pain from dura)
What fibres does the trigeminal motor nucleus provide?
motor to the muscles of mastication, tensor tympani, mylohyoid, ant. belly of digastric, tensor veli palatini
What nuclei contribute to the facial nerve?
Facial motor nucleus
Salivatory nucleus
Solitary nucleus
Spinal trigeminal nucleus
What fibres does the facial motor nucleus provide?
Motor fibres for the muscles of facial expression
What fibres does the salivary nucleus provide?
Parasymaptehtic innervation to salivary glands for facial and glossopharyngeal
What fibres does the solitary nucleus provide?
special sensory taste and visceral information
for facial, glossopharyngeal and vagus
What nuclei contribute to the glossopharyngeal nerve?
Solitary nucleus
Nucleus ambiguus
Salivatory nucleus
Spinal trigeminal nucleus
What fibres does the nucleus ambiguus provide?
motor to the pharynx and larynx
for glossopharyngeal and vagus
What nuclei contribute to the vagus nerve?
Dorsal (motor) nucleus
Solitary nucleus
Spinal trigeminal nucleus
Nucleus ambiguus
What fibres does the dorsal (motor) nucleus provide?
Parasympathetic fibres for the vagus
The ___________ tract is part of the pyramidal tract that provides motor to the cranial nerves
corticobulbar
Describe what the reticular formation is
The reticular formation is a network of loosely aggregated cells with cell bodies, axons and dendrites intermingling in the central core of the brainstem. It is distinct from the long pathways (like the medial lemniscus, or the corticospinal tract) and the specific distinct cell groups (like cranial nerve nuclei).
Describe the functions of the reticular formation
Integrate cranial nerve reflexes.
Participate in conduction and modulation of pain.
Influence voluntary movement.
Regulate autonomic activity.
Integrate some basic functions, like respiration and sleep.
Activate the cerebral cortex: major component of the Ascending Reticular Activating System (a medial bilateral lesion of the brainstem reticular formation at or above the upper pons causes irreversible coma).
