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)
What is the transverse tube (T-Tube)
muscle membrane surrounding sarcoplasmic reticulum which allows propagation of action potentials
What is the Sarcoplasmic reticulum
Part of muscle cell that:
1. Releases Ach
2. Stores Calcium
3. Facilitates cross bridge action of actin-myosin
(Basically it activates muscle contractions)
What is the Z disc?
End of sarcomere
What is the M line?
Holds together myosin at sarcomere center
What is titin?
Holds Actin and myosin together and prevents sarcomere from being pulled apart
How does actin and myosin move in the sarcomere?
Myosin ( in the middle) pulls the Actin towards the M-Line (the center)
Ca+ binding to ______ causes _______ to uncover sites on the actin which allows for myosin to bind to it
Ca+ binding to troponin causes tropomyosin to uncover sites on the actin which allows for myosin to bind to it
Healthy innervated muscles will ______ sarcomeres when immobilized in shortened position for prolonged time
Healthy innervated muscles will ____ sarcomeres when immobilized in lengthened position for long time
Shortened - lose
Lengthened - gain
The cutaneous withdrawal reflex is a ____________ reflex that occurs in response to pain before concious awareness
monosynaptic (one synapse)
What are Muscle cramps?
Painful contractions of muscle due to overstimulation of motor or sensory neurons
What are fasciculations
visible fast twitches of all muscle fibers in 1 motor unit Normal OR pathological
(different than a fibrillation which is not visible - always pathological)
What is myoclonus and is it always pathological?
Brief contractions of muscle/group of muscles
Normal Or Pathological
What are tremors?
Involuntary rhythmic mvmts
Can be normal or pathologic
Pathologic: postural, orthostatic, intention
Decrease or loss of reflexes (DTRs)
Paresis or paralysis
Muscle atrophy
Decrease or loss of muscle tone
Fibrillations
These are all signs of ________
Motor Neuron Lesion
What is the purpose of a NCV (nerve conduction velocity study)
To diagnostically differentiate between disorders of:
Motor neuron
NM junction
Muscle
What is the purpose of an electromyography
differentiate between denervated muscle or myopathy
Note: EMG and ECV typically done on same visit
What is post polio syndrome?
Disease of lower motor neurons
- Motor units die due to polio
- Motor units recover forming giant motor units
- Motor units die due to excessive metabolic demand causing new weakness and fatigue
The lateral horn of the gray matter is present only in:
What is the lateral horn for?
T1-L2
Autonomic function
What order of neurons are found in the ventral horn?
cell bodies of 1st order neurons leaving the spinal cord to the muscles they innervate
The subarachnoid space is also called the…
intrathecal space
note: where the CSF is found
What arteries supply the ventral and dorsal spinal roots?
Anterior and posterior radicular arteries
These arteries come off of segmental spinal arteries
The spinal cord only occupies ____% of the intervertebral foraminal space
33-55%
In the spinal cord: ______ motions can increase the pressure at all vertebral levels normally
cervical motions
What is the only tract who’s information gets all the way to the medulla before synapsing?
Dorsal column
True or false: ascending and descending spinal signals synapse on the same interneurons
true
Renshaw cells are activated by the ___________ of gamma motor neurons
recurrent branches
(Branches that turn back onto their own cell body)
What are the 3 CNS levels needed for urinary continence?
Frontal Cortex, Pons, Sacral cord
During Tethered cord syndrome
Damage to anterior cauda equina will lead to:
Whereas stretch to spinal cord will lead to:
Anterior cauda equina: LMN signs (PNS)
Stretch to spinal cord: UMN signs(CNS)
Sodium channels have an ____ refractory period but calcium channels do not
Absolute
Voltage gated Na+ channels are located on the….
Nodes of Ranvier
Note: also where AP is generated
What’s it called when the AP leaps from one node of ranvier to another
Salatory conduction
Nodes of ranvier are spaced ___mm apart
0.2-2mm apart
What kind of conduction happens at unmylinated axons?
Continuous
Note: not as fast as salatory
Cardiac and smooth muscle has the _____ conduction time compared to skeletal muscle and nerves
cardiac/smooth muscle - slowest
Skeletal- kinda fast
Nerves- speedy speedy speedy
What kind of synapse goes towards a cell body?
(axoaxonic/axodentritic/axosomatic)
Axosomatic
Presynaptic effect can only occur in ____ synapses.
(axoaxonic/axodentritic/axosomatic)
Axoaxonic
Where the presynaptic terminal points to another neuron’s presynaptic terminal
- action potential comes to presynaptic terminal
- presynaptic terminal membrane depolarizes –> open voltage-gated __________
- Ca2+ flows in & frees Ca2+ stored in cell –> _________ with neurotransmitters inside are triggered to move toward release site
- vesicles fuse w/ presynaptic membrane & release NTs into ___________
- NTs spread across cleft
- NTs touch matching postsynaptic receptor –> binds
- ___________ alters shape –> opens ion channel OR triggers intracellular messengers
Voltage gated calcium channels
Vesicles
Synaptic Cleft
Post Synaptic Receptor
What activates the secondary messenger system?
What is the second messenger?
- Neuromodulator
- G-Protein (produced inside of neurons)
What are the 3 “amine” class neurotransmitters
Dopamine
Serotonin
Norepinephrine
What disease is caused by damage of AcH receptors on muscles?
Myasthenia Gravis
Ach is considered a neurotransmitter in ______, but a neuromodulator in the ______
Muscles
Brain
In Huntington disease, you see low levels of what neurotransmitter?
GABA
As well as glycine which is also inhibitory
Receptors for ________ are all secondary messenger systems
Dopamine
In PTSD, you see excessive _____ levels
Norepinephrine
What neurotransmitter is involved in mood, pain perception, arousal, and motor activity?
Serotonin
In ______ syndromes, substance P can act as a neuromodulator
Pain syndromes
What do neural crest cells form?
Periphery sensory neurons
Autonomic Regions
Endocrine glands
The spinal cords stops growing at ___ years old, the vertebral column stops growing at ___
4-5
16-18
What day does brain development occur?
Day 28
In development, The posterior region of the forebrain remains near the midline to form the….
Diencephalon: Thalamus, Hypothalamus
Which part of the developing brain becomes the telencephalon?
(Forebrain/Midbrain/Hindbrain)
Forebrain
Cortex refers to….
The layers of cell bodies on the surface of the hemispheres
What does the central canal of the forebrain form?
The lateral ventricles
The insula is considered the ____ lobe of the cortex
5th
Neurons sprout ________ that they use to sample potential environments, recoiling from some areas and attracted to others
Growth cones
What happens when growth cones reach a target cell?
Synaptic vesicles form and microtubules extend to the presynaptic membrane
Muscle fiber type is dependent on the __________ which shapes the development of muscles
Type of innervation
(The neurons decide if it’s fast or slow twitch)
Myelination of long axons is finished by ___ years old
Myelination of motor neurons out the cortex is finished by __ years old
3 years old
2 years old
When abnormal events occur prior to __ weeks gestation, major deformities of the nervous system will be present
20 weeks
What is the lateral wall of the lateral ventricles?
Caudate nucleus
What is below the lateral ventricles?
Thalamus
What is above the lateral ventricles?
Corpus callosum
The 3rd ventricle is surrounded by the…..
Diencephalon
Where is the inner and outer layer of the dura not fused?
Dural sinuses which collect CSF and blood
what layer of the dura continues as spinal dura
inner layer
(not the outer layer)
What part of the arachnoid matter connects to the pia matter and suspends the brain
arachnoid trabeculae
what are the three layers of the choroid plexus? AKA what three layers does CSF have to go through
capillaries
connective tissue
epithelial cells
what is the triad of symptoms for hydrocephalus
-gait
-incontinence
-cognitive deficits
where does noncommunicating hydrocephalus usually occur
cerebral aqueduct
what kind of aneurysm is most common
what is this type called when it happens at a cerebral artery
sacular
berry
what type of aneurysm happens on both sides of the blood vessel
fusiform
in what ventricle is intracranial pressure measured
what is the normal range of intracranial pressure?
Lateral Ventricle
5-15, (20 is pathological)
What type of herniation puts pressure on the the midbrain, the reticular formation, and CN3
Uncal
What type of hernation causes stretching of the basilar artery and bilateral paralysis with impaired conciousness
central herniation
what kind of herniation can put pressure on the brainstem and block the 4th ventricle
tonsillar
what is a transient ischemic attack
brief localized loss of brain function that resolves within 24 hrs
(precursor to a stroke; becomes a stroke if it lasts more then 24 hours(CVA))
__% of strokes are infarcts
80%
What has a smaller receptor field, subcutaneous or superficial receptors?
Superficial receptors have a smaller field (more accurate 2 point discrimination)
Patients with _______ will have similar preformance preforming tasks with eyes open and eyes closed
cerrebellar ataxia
(because they cant cooridinate movements anyway)
Which disorder still has proprioception: Sensory ataxia or Cerebellar ataxia
Cerebellar ataxia
varicella zoster virus causes chicken pox & infects ________ –> virus remains latent in ____________ –> breaks out & travels distally to nerve endings
Causing…. Shingles
Dorsal Root Ganglion
what areas of the brain are active during perception of pain
cingulate and insular
the dorsal horn releases __________ to inhibit pain
enkephalin or dynorphin
parathesia vs dysthesia
parathesia- tingling/numbness
dysthesia- burning/shooting/painful
What is the term for pain from a stimulus that wouldn’t normally cause pain
allodynia
note: with allodynia, abnormal activation of microglia may be implicated
In primary hyperalgesia, stimuli that would normally be _________ now causes excessive sensitivity
mildly painful
In secondary hyperalgesia the pain spreads to ____________
areas away from the injures site
increased pain due to repeated stimulus or continued presence of single stimulus are examples of….
Temporal summation
tenderness & stiffness of muscles & neighboring tissues & achy pain w/o painful external stimuli is called…
Fibromyalgia
Note: small fiber myopathy contributes to fibromyalgia
What are signs of excessive intracranial pressure?
HA upon awakening
HA caused by coughing, sneezing, straining, vomiting
worse when laying down
___% of ppl seeking primary care for LBP have no definitive specific tissue injury & __% resolves post 6-12 wks
90%
70%
Allodynia is likely caused by _______ where demyelination allows an AP in 1 neuron to cause an AP in another neuro
ephaptic transmission/cross talk
What muscle spindles do 1a fibers go to?
What muscle spindes do type 2 fibers go to?
What muscle spindles do static gamma motor neurons go to?
What muscle spindles do dynamic gamma motor neurons go to?
ALL
All but dynamic nuclear bag
All but dynamic nuclear bag
Only dynamic nuclear bag
What kind of gamma motor neurons do golgi tendon organs get?
1B
Golgi tendon organs can either cause autogenic ______ or ________
Inhibition or activation of the same muscle they originate from
What is external strabismus
Eye fixed in abduction
(trochlear nervea and occulomotor not working)
if you have trochlear nerve not functioning, you will expect to see a head tilt to the _____ side
head tilt to opposite side
What is the main symptom you’d expect to see if the Abducens nerve is damaged
double vision
The cochlear nuclei transmits auditory information to what 3 structures?
- reticular formation
- inferior colliculus
- medial geniculate body
Which salviary gland is not associated with the facial nerve?
Parotid
(Facial nerve controls all of the rest)
What structure integrates info from both ears in order to locate sound?
Inferior colliculus
which structure serves as thalamic relay station to primary auditory cortex?
medial geniculate body
What is more common: Sensorineural deafness or conductive deafness
Conductive Deafness
