Quiz 2 Flashcards
Cranial Nerves receive impulses from the cortex from the __________ tract
Corticobulbar
For the cranial nerves I-IV are at the _____ level of the brainstem
Midbrain
For the cranial nerves, V-VIII are at the _______ level of the brainstem
Pons
For cranial nerves, IX-XII are at the level of the ________
Medulla
Are cranial nerves UMN’s or LMNs?
LMNs
Cranial nerves innervate muscles of which structures?
jaw, face, pharynx, larynx, soft palate, tongue and neck
The cranial nerves of speech production are….
Trigeminal, facial, glossopharyngeal, vagus, spinal accessory, and hypoglossal
When would you test the olfactory nerve?
If a frontal lobe tumor is suspected
What are some conditions that might cause a damaged olfactory nerve?
Closed head injuries, nasal obstruction, viral infections, Parkinson’s, MS, Alzheimer’s
How do you test the olfactory nerve?
Ask if patient can smell vanilla or cinnamon in each nostril
How to test visual field
Card at patient’s bedside
What three nerves control eye movement and pupil diameter?
III- Oculomotor
IV- Trochlear
VI- Abducens
How to test these oculomotor, trochlear, and abducens
Hold up a finger in front of your partner. Tell them to keep their head still and follow your finger up and down, right and left. Do their eyes follow your finger?
What does the Trigeminal Nerve (V) control
Facial muscles and muscles of mastication
How to test the trigeminal nerve
Palpate the masseter muscle as the patient bites down hard.
Open mouth and resist examiner’s attempt to close the mouth.
Jaw jerk reflex
What are the three branches of the trigeminal nerve?
Opthalmic, Mandibular, Maxillary
What does the mandibular branch of the trigeminal nerve do?
Innervates muscles of the jaw and velum for elevation and lowering
What function is the Abducens (VI) nerve responsible for?
Eye movement
How to examine the facial nerve generally?
Examine facial symmetry. Check taste.
How to examine the motor portion of the facial nerve?
Have the patient wrinkle their forehead Puff out cheeks Close eyes tight Show their teeth Purse their lips or blow a kiss (orbicularis iris)
How to examine the sensory portion of the facial nerve?
Dip a cotton tip in sweet, salty, sour, or bitter. Apply to one side then the other side of the extended tongue.
The portion of the facial nerve that serves the muscles of the lower face receives unilateral innervation from the ______ side of the brain
contralateral
The portion of the facial nerve that serves the muscles of the upper face receives bilateral innervation from the _________
right and left corticobulbar tracts
Upper motor neuron lesions such as stroke cause _____________
Contralateral facial weakness, sparing the forehead
Lower motor neuron lesions such as facial nerve injury cause ___________
Weakness involving the whole ipsilateral face
What are the roles of the glossopharyngeal nerve?
Innervates the stylopharyngeus muscle which assists in the elevation of the pharynx and larynx.
Plays a role in resonance and phonation by shaping the pharynx
Contributes to the gag reflex, an important component of swallowing.
What are some of the structures served by the Vagus nerve (CN X)?
Heart, velum, larynx, intestines
What are three branches of CN X that have special importance to speech production?
Pharyngeal nerve branch,
Exterior superior laryngeal nerve branch
Recurrent nerve branch
Which CNs are tested together?
CN IX and X
How are they tested?
Symmetrical palate elevation while saying “ah”
Does the patient gag when the posterior pharynx is brushed?
What is the main function of the spinal accessory nerve?
Help turn, tilt, and thrust the head forward
What muscles does the spinal accessory nerve innervate?
Trapezius, sternocleidomastoid- related to posture for speech and feeding
How do you test the spinal accessory?
To test the strength of the muscles used in head movement, put your hands on the sides of the patient’s head. Tell the patient to move his or her head from side to side. Apply only light pressure when the head is moved.
What does the hypoglossal nerve innervate?
Intrinsic muscles of the tongue and most extrinsic muscles
Supplies muscles of the tongue and muscles surrounding the hyoid bone.
How do you test the hypoglossal nerve?
Have patient stick out tongue and move it from side to side.
Strength can be tested by having the patient push the tongue against a tongue blade.
DDK
Note any atrophy or fasiculations of the tongue while it is resting on the floor of the mouth
Ask patient to stick out tongue and note whether it curves to one side or not
Ask patient to move tongue from side to side and push it forcefully against the inside cheeks
Tongue fasiculations and atrophy are indicative of…
LMN lesions
Unilateral tongue weakness can cause the tongue to deviate toward the _____ side
Weak
Abnormal articulation can be the result of lesions in…
Muscles of articulation, neuromuscular junction, peripheral or central portions of cranial nerves V, VII, IX, and XII
What are the two branches of the auditory nerve
Vestibular, cochlear
Vestibular branch carries impulses for….
balance
Cochlear branch carries impulses for…
hearing
The Glossopharyngeal nerve innervates the ______ muscle which assists in the elevation of the pharynx and larynx
Stylopharyngeus
The major role of the spinal accessory nerve (XI) is to….
help turn, tilt, and thrust the head forward, posture for speech and feeding
Name two muscles that the spinal accessory nerve innervates
Sternocleidomastoid, trapezius
How to test the spinal accessory nerve
Put your hands on the sides of the patient’s head. Tell the patient to move their head from side to side. Apply only light pressure when the head is moved.
What is the neuromuscular junction?
Point at which axons of the PMN make synaptic connections with muscle cells; .
What is an action potential?
A neural impulse, a brief electrical charge that travels down an axon
Generated by the movement of positively charged atoms in and out of channels in the axon’s membrane
What is a threshold?
The level of stimulation required to trigger a neural impulse
What is a synapse?
Junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron.
A tiny gap at this junction is called a synaptic gap or cleft.
What are neurotransmitters?
Chemical messengers that transverse the synaptic gap between neurons.
When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether it will generate a neural impulse.
What are the components of the cortical level of motor speech function?
Primary motor cortex, premotor cortex, supplementary motor area, Broca’s area
What are the components of the direct motor system (pyramidal system)
Corticobulbar tract, corticospinal tract
What are the components of the indirect motor system (extrapyramidal system)
Subcortical level- basal nuclei
Descending pathways
What kind of movement does the Direct Motor System (pyramidal system) control?
Muscle tone
Conscious fine, skilled movements
In the face and distal limbs
Operates at a conscious level
What do descending motor pathways do in general?
Deliver impulses from the brain to the spinal cord.
What do indirect (extrapyramidal) pathways control?
Subconscious motor programs (arm swing)
Help maintain appropriate level of skeletal muscle tone
What is the general path that the corticobulbar tract takes?
Descend through the sub cortex and brainstem to connect with cranial nerves that control the oral mechanism.
Courses through the internal capsule, then the cerebral peduncles, then mixes up with other fibers in the pons, then on the ventral surface of the medulla in the medullary pyramids.
The path of the corticospinal tract
Arise from various sensory motor areas of the brain
System descends and enters the diencephelon where its fibers are concentrated in a small area called the internal capsule
Fibers enter the brainstem and descend through the peduncles of the midbrain, pons, and pyramids of the medulla
At the lower margins of the medulla, the fibers decussate to the opposite side
Damage to the corticospinal tract can cause
Loss of muscle strength, reduced dexterity of the hands and fingers
What kinds of muscles does the corticospinal tract regulate?
Muscles that maintain balance and posture, muscles controlling coarse movements of the proximal portions of the limbs, muscles that control head neck, and eye movement.
What is the rubrospinal tract responsible for?
Large muscle movement as well as fine motor control
Terminates primarily in the cervical spinal cord
Facilitates flexion in the upper extremities
Upper limb, but not lower limb control
What is the pathway of the reticulospinal system and what kinds of muscles/movements does it control?
The reticulospinal system is an extrapyramidal motor tract that descends from the reticular formation in two tracts to act on the motor neurons supplying the trunk and proximal limb muscles. Mainly involved in locomotion and postural control.
List deficits that involve too little movement
Rigidity (resistance to movement, stiffness/tightness, slowness)
Bradykinesia (reduced speed of muscle activation; delays and false starts, slowness)
Reduced range of motion (hypokinesia)
Tremor (static or resting)
Breaking and Freezing problems (starting and stopping; e.g. stopping at the foot of the stairs)
To what other major structures do the basal ganglia have fibers connected to?
Cerebral cortex
Thalamus and hypothalamus
Descending fibers to the spinal cord
What is chorea?
An involuntary movement disorder, one of a group of neurological disorders called dyskinesias
What is athetosis
Symptom characterized by slow, involuntary, convoluted, writhing movements of the fingers, hands, toes, and feet and in some cases arms, legs, neck, and tongue
List some upper motor neuron symptoms
Spastic hemiplegia Increased muscle tone \+ Babinski sign Hyperreflexias Loss of abdominal reflexes
List some clinical signs of a pyramidal syndrome
Spasticity, involuntary movement is absent, Positive Babinski sign, increased muscle stretch reflex
List some clinical signs of an extrapyramidal indirect motor system syndrome
Rigidity, involuntary movement is present, absent babinski sign, decreased stretch reflex
Cerebellar control circuit lesions can result in what kind of dysarthria?
Ataxic
Ataxic dysarthria is characterized by….
Incoordination, hypotonicity
What are confirmatory signs of cerebellar control circuit lesions?
Slow voluntary movements Jerkiness of movements Wide based gait Intention or terminal tremor Essential tremor
What is the PNS also known as
The final common pathway
What does the final common pathway refer to?
Cranial nerves that attach to the brainstem and spinal nerves that attach to the spinal cord
The final common pathway implies that the…
PNS serves as the last route of the nervous system
What is the role of the lower motor neuron system in speech?
To carry out the commands delivered by UMNs as delivered by the cerebral cortex and as influenced by the basal ganglia and cerebellar control circuit
Name symptoms of damage to LMN system
Eliminate function of motor unit
Weakness of muscles and reduce tendon reflexes
Muscle tone is flaccid
Absent or greatly reduced babinski
LMN lesion symptoms can be seen in which disorders?
Myasthenia gravis and muscular dystrophy
UMNs originate in the ________ and synapse onto cranial nerve nuclei in the _________ or onto cells in the __________
motor cortex
brainstem (corticobulbar)
spinal cord (corticospinal)
If UMNs are damaged, there will be…
Spasticity, reduction in the ability to initiate skilled motor movements, babinski sign
What is spasticity
Increased muscle tone, reflexes are exaggerated
If LMNs are damaged, the result is
Flaccid paralysis
UMN pathways are
Direct/pyramidal system, basal nuclei and cerebellar control circuit
