Written Concepts for Test 1 Flashcards
If you have a upper motor neuron lesion on one side of the facial nerves what happens?
Only the contralateral lower part of the face will be affected because the uppr half is innervated by both sides of the brain
If you have a lower motor neuron lesion to one side of the facial nerves what happens?
Whole side of the face is paralyzed
What is the only sensory input that does not go through the thalamus?
Olfactory Nerve
What is the only cranial nerve to exit on the dorsal portion of the brainstem?
Trochlear
What cranial nerves are involved in the pupillary light reflex
2: sensory
3: motor
Which branch of the trigeminal is the only one with a motor component?
Mandibular
What cranial nerves are involved in the Corneal blink reflex
5: Sensory
7: Motor
Where is the cell body for the Light Touch sense of the trigeminal nerve?
Trigeminal Ganglion
Where is the cell body for fast nociception of the trigeminal nerve?
Trigeminal Ganglion
Where is the cell body and the first synapse for proprioception of the trigeminal nerve
mesenphalic nucleus of midbrain
Where is the destination of the information carried by the proprioception portion of the trigeminal nerve
reticular formation and cerebellum
What nerve is responsible for the lacrimal gland (tears in the eye) and most salivary glands?
Facial nerve via the PARASYMPATHETIC superior salivatory n
Contricting the eye is _____sympathetic whereas dialating the eye is ____sympathetic
constricting: parasympathetic
dilating: sympathetic
True or false: Trigeminal neuralgia involves sensory loss to portions of face innervated by trigeminal nerve
False, no sensory loss. It is sharp shooting pain
What is bells palsy
Diagnoses of exclusion: Virus swells the facial nerve and causes ischemia
What cranial nerves control the gag and swallowing reflex?
CN 9: Sensory
CN 10: Motor
Hypoglossal UMN lesion vs LMN lesion
UMN Lesion: Tongue deviates to opposite side of lesion due to inactivity of contralateral tongue muscles
LMNS lesion: Tongue deviates to same side as lesion due to inactivity of ipsilateral tongue muscles
Summary: Hypoglossal UMN is CONTRALATERAL, LMN is IPSILATERAL
What is Dysarthria
Poor control of speech muscles
Smaller motor neurons innervate ____ twitch fibers whereas larger motor neurons innervate ____ twitch fibers
Smaller - Slow Twitch
Larger- Fast Twitch
What is a presynaptic bouton
Swelling at the end of the axon of motor neurons, it lies over the “motor end plate”
What is rate coding?
Increased motor neuron firing frequency will lead to higher force summation of muscles
At lower frequencies, ____ twitch muscles fibers have higher force summation than _____ twitch muscle fibers
Slow twitch muscle fibers have higher force summation than fast twitch
(but not higher overall force)
What type of muscle fibers have the fastest time to peak force and fastest contraction time
Fast Twitch
______ motor neurons are recruited and fire before _____ motor neurons are recruited
Smaller are recruited before larger
Why? They have smaller membranes and are easier to depolarize (larger input resistance AKA ohms law, voltage = current x resistance)