Lecture 10: Cranial Nerves Flashcards
What are the 12 cranial nerves?
on on on they travelled and found voldemort guarding very ancient horcruxes
- Olfactory
- Optic
- Occulomotor
- Trochlear
- Trigeminal
- Abducens
- Facial
- Vestibulocochlear
- Glossopharyngeal
- Vaugs
- Accessory
- Hypoglossal
What is the mneumonic for the function of each cranial nerve?
Some Say Marry Money But My Brother Says Big Brains Matter Most
S = Sensory M = Motor B = Both
Write some notes on the olfactory nerve:
Doesnt have specific nucleus in the brain that it projects to.
Has projects to the olfactory and limbic system. Hence smells can trigger memories and emotions.
Also projects to hypothalamus where no conscious sense of smell influences taste and satiety.
What is the main relay nucleus of the optic nerve?
lateral geniculate nucleus
What are the cranial nerves of eye movement?
Cranial nerves 3,4,6
What happens if one of the cranial nerves involved in eye movement is damaged?
Then those muscles are no longer innovated and resultingly the eye moves in line with the direction of the functional cranial nerves i.e no longer neutral
Where are the nuclei of the occulomotor, trochlear and abducens cranial nerves?
Occulomotor = Occulomotor nucleus (at sup. colliculus lvl) Trochlear = Trochlear nerve (@midbrain level with inf. colliculus) Abducens = Abducens nuclei (@pontomedullary junction in the pons)
Describe the trigeminal nerve:
Motor and sensory nerve.
Projects to the trigeminal ganglion and splits into three nerves;
Opthalmic nerve (V1) (Sensory) Maxillary nerve (V2) (Sensory) Mandibular nerve (V3) (Sensory and Motor)
What are the nuclei of the trigeminal nerve?
Mesocephalic nucleus; Located in midbrain, rostral pons. Functions as a proprioceptive pathway to regulate bite strength in response to proprioceptive info. Communicates to the trigeminal motor nucleus.
Principle sensory nucleus- mid pons, lateral to motor nucleus. ; proprioception, fine touch, vibration.
Spinal trigeminal sensory nucleus: Lateral tegmentum of medulla. Unusual in that it receives input from 7,9 and 10 cranial nerves as well regarding pain, temp and crude touch.
What are the nuclei of the facial nerve?
Facial motor nucleus
Solitary nucleus (sensory)
Sup. salivatory nucleus (ANS)
What are the nuclei of the vestibulocochlear nuceli?
Cochlear nuclei
Vestibular nuclei
Both sensory
What are the nuclei of the glossopharyngeal nuclei?
Inf. salivatory nucleus (PSN)
Solitary nucleus (Taste-sensory) Dorsal motor nucleus and nucleus ambiguens (Motor)
Trigeminal sensory nucleus (Pain, temp)
What are the nuclei of the vagus nerve?
Nucleus ambiguens (as well as CN8) (Motor)
Dorsal nucleus of Vagus (ANS)
Solitary nucleus (Contains gustatory nucleus, all a sensory nucleus)
Spinal trigeminal nuclei (all general sensory info passes through this)
What cranial nerve nuclei recieves all general sensation?
Spinal trigeminal nuclei
What are the nuclei of the accessory nerve?
Accessory nuclei (located in spinal cord) (motor)
What are the nuclei of the hypoglossal nerve?
Hypoglossal nuclei (in midbrain) (motor)
Describe the pathway of the optic nervee:
The optic nerve travels through the eye entering the optic chiasm and continuing through the optic tract to the lateral geniculate body. This sends optic projection fibers to the primary visual cortex
What muscles does the occulomotor nerve control?
Levator palpebrae superioris Superior rectus Medial Rectus Inferior rectus Inferior oblique
What muscles does the trochlear nerve control?
Superior oblique
What muscles does the abduces control?
Lateral recuts
What is the function of the trigeminal nerve?
Mixed:
Sensory: Sensation from face, mouth and tongue (ant. 2/3)
Motor: Muscles of mastication
What is the function of the facial nerve?
Mixed
Motor: Muscles of facial expression
PNS: Salivation, tear film
Sensory: Taste, Post 2/3 of tongue.
Function of the vistubocochlear nerve?
Hearing, Balance, Spatial orientation
Function of the glossopharyngeal nerve?`
Taste
Salivation
Arterial pressure, blood oxygen and CO2 (Carotid body and sinus)
Sensation of palate, tongue, middle ear
Muscles of larynx.
What is the function of the vagus nerve?
Taste (back of throat)
Muscles of larynx and pharynx
Sensation: Outer ear, larynx
Sensation of Viscera and PNS
Function of accessory nerve?
Muscles: Trapezius and sternocleidomastoid
Function of hypoglossal nerve?
Muscles of the tongue
How do the cranial nerves act in the corneal (blink) reflex?
Afferent: Trigeminal
Efferent: Facial nerve
How do cranial nerves act in the pupillary light reflex?
Afferent: Optic nerve
Efferent: Occulomotor nerve
How do cranial nerves act in the gag reflex?
Afferent: Glossoharyngeal nerve
Efferent: Vagus nerve
A 45-year-old man is referred to the neurology clinic by his
primary care physician with right facial pain. He states that it is
a sharp shooting pain radiating over his right cheek. It is
exacerbated by chewing, brushing his teeth, and shaving. The
pain is intense and disrupts his activities of daily living. He is
otherwise healthy and there is no history of neurological
problems.
Trigeminal neuralgia
Ms. Z, a 30-year-old pregnant female, recreational badminton
player, who spontaneously woke up with the inability to
voluntarily move the right side of her face, including the inability
to close her right eye, and slight drooping at the corner of her
mouth. She tried to explain to her husband what was
happening, but lacked the motor control to enunciate words.
Facial nerve, bells palsy
