Just everything... Flashcards
Holy eft…just get us through this exam!
List somatosensory sensations carried EXCLUSIVELY by the DC/ML
Vibration (fine touch), proprioception, texture
List somatosensory sensations carried EXCLUSIVELY by the ALS
Temperature, slow pain, visceral pain
List somatosensory sensations carried EXCLUSIVELY by both the DC/ML and ALS
Pressure touch, hair associated touch, fast pain
Special skin receptor sensing texture (discriminatory touch)
Meissner corpuscles
Special skin receptor sensing vibration
Deep = Pacinian corpuscles. Superficial = Meissner corpuscles
Special skin receptor sensing pressure
Deep = Pacinian corpuscles. Superficial = Merkel’s disks
Where are the cell bodies in the DC/ML pathway?
DRG - Caudal Medulla (Gracile and Cuneate Nuclei) - Ventral Posterior Lateral Nucleus of the Thalamus - Precentral Gyrus
Where do the tracts of the DC/ML pathway terminate?
Pre central gyrus of the cerebral cortex
Do the fibers of the DC/ML pathway decussate? If so, where?
Yes, in the caudal medulla’s pyramidal decussation
Do any branches come off the DC/ML pathway? If so, what function do they serve?
Yes, but they are going to the cerebellum and serve to provide proprioceptive feedback of what the body is doing
Where do the corticobulbar fibers decussate?
In the middle Pons
What fibers make up the bulk of the INCOMING middle cerebellar peduncle fibers?
The corticobulbar fibers from the basilar pontine nuclei
Once in the cerebellum, what happens to the corticobulbar fibers?
They split with some going to the deep cerebellar nuclei and others going to the cerebellar cortex
Proprioceptive loss if the dorsal column at C4 was destroyed?
Loss of proprioception on the same side
Proprioceptive loss if the DRG at C4 was destroyed?
Loss of proprioception on the same side
Proprioceptive loss if the ALS at C4 was destroyed?
No loss of proprioception. ALS is NOT proprioception
Proprioceptive loss if the lateral portions of the primary somatosensory cortex was destroyed?
Loss of proprioception of the face and upper extremities on the opposite side
Proprioceptive loss if the medial portions of the primary somatosensory cortex was destroyed?
Lower limb proprioceptive loss on the opposite side
What sensation is unique in that it does not reach the cerebral cortex by going through relay nuclei?
Olfaction
When does sensation enter conscious awareness?
When the signal reaches the cerebral cortex
T/F DC/ML neurons are larger and more heavily myelinated than ALS neurons
TRUE
Where does DC/ML pathway information decussate?
In the caudal medulla
Where does the ALS pathway decussate?
In the spinal cord
T/F Many more ALS axons reach the cerebrum
FALSE. Many more DC/ML fibers do…which contributes to such fine perception and localization of sensation
When cell damage occurs, probradykinin is converted to ____ which minds to pain receptors on the free nerve endings of axons causing them to fire.
Bradykinin
NSAIDs inhibit the formation of ____ which in turn prevent bradykinin from causing free nerve endings to fire.
Prostaglandins (COX 1 and COX 2)
In a life or death situation, human beings can reduce the amount of pain perceived. This occurs because the cerebrum can send a signal to the _____ of the midbrain where opioid containing ____ become excited. These ____ then activate neurons that project down to serotonergic nuclei located within the ____ medulla which then project down to lamina ____ of the ____ horn gray matter of the spinal cord. Here, these serotonergic nuclei activate ____ containing interneurons which pre-synaptically inhibit pain in afferent nerve endings. This in effect…”turns off” the ____ synapse in the pain pathway
Periaqueductal gray nucleus, interneurons, opioid containing interneurons, ventral, 2, dorsal, opioid, first
Where do opioid drugs act?
On the periaqueductal grey nucleus of the midbrain as well as directly on the dorsal horn grey matter
What type of receptors the target cells of opioids express?
Mu
The sensations of fullness and ischemia are considered…
Visceral pain
Of the four main types of special mechanoreceptors, which is the most sensitive to vibration?
Merkel
How does proprioceptive feedback from the body enter the cerebellum?
Via the inferior cerebellar peduncle
T/F The feedback through the inferior cerebellar peduncles is specific to the corticospinal system
FALSE. It contains non specific input from both the corticospinal and bulbospinal systems
Proprioceptive feedback comes from the ____
DC/ML somatosensory system
T/F There is a branch from the DC/ML system that doesn’t go directly to the brain, but branches off and goes into the cerebellum. It’s called the ____
TRUE. This is called dorsal spinocerebellar tract
A proprioceptive sensation reporting on what was intended to be a conscious and voluntary movement that originated from the motor cortex is sent via the DC/ML which branched up the dorsal spinocerebellar tract to a deep motor neuron in the cerebellum. From there, where will the signal be sent?
Back to the motor cortex via a relay in the thalamus to report on the success or failure of the movement.
A proprioceptive sensation reporting on what was intended to be an unconscious movement that originated from the vestibular nuclei is sent via the DC/ML which branched up the dorsal spinocerebellar tract to a deep motor neuron in the cerebellum. From there, where will the signal be sent?
The vestibular nuclei to report on the success or failure of the movement
T/F Efferent axons from the cerebellum go the same region of the brain that initiated the intended movement in the first place.
TRUE
What two places within the cerebellum does information about intended movement go to?
Deep cerebellar nuclei, cerebellar cortex
A block in the cerebral aqueduct would cause what form of hydrocephalus? Communicating or non-communicating? What ventricles would be affected?
Non-communicating. The lateral and 3rd ventricles.
A “brain” bleed that prevents CSF from exiting the arachnoid villa would cause what form of hydrocephalus? Communicating or non-communicating?
Communicating. All ventricles.
Complete: Afferents to the cerebellum that are either _____ command or _____ sensory information enter the cerebellum through their respective _____. They then split. One short branch goes to the _____ and one long branch to the _____. The short branch reaches its target first and causes these _____ to fire a bunch of action potentials toward the ____ (think morse code). The long branch excites _____ neurons in the _____ which in turn send their axons to excite _____ in the molecular layer. These cells then send their axons through the _____ to synapse with the _____ to inhibit them and stop them from firing.
Motor, proprioceptive, peduncle, deep cerebellar nuclei, cerebellar cortex, deep cerebellar nuclei, brain, granule, cerebellar cortex, purkinje neurons, cerebellar white matter, deep cerebellar nuclei
If both the intended action and actual action of a conscious or unconscious movement is perceived by the cerebellum…and the “code” is the same, this means what?
What you want to do or what your brain intends to do and what is actually happening are the same. Conversely, if they “codes” are NOT the same, then corrections must be made because what is supposed to happen and what is actually happening are different.
Consciously, what part of the motor cortex generally “plans” a movement? What part of the motor cortex generally “controls or executes” a movement?
Pre-motor cortex plans, primary motor cortex executes.
Where do corticospinal fibers cross the midline?
Pyramidal decussation
When do corticobulbar fibers cross the midline and where does this occur?
Right after they synapse in the pons and before they enter the cerebellum…it occurs in the Pons
What comes in the inferior cerebellar peduncle?
Proprioceptive feedback from the body
What come in the middle cerebellar peduncle?
Motor input from the brain
What leaves the superior peduncle?
Information “code” about intended and actual movement headed toward the brain
If you have damage to the right side of your cerebellum, you will see ramifications in the ____ side of the body.
Right, same, ipsilateral
If you have damage to the right side of your cerebrum, you will see ramifications in the ____ side of your body.
Left, opposite, contralateral
Where are Mu receptors located?
In the periaqueductal grey and the dorsal horn grey matter
Where are the vestibular nuclei and how many are there?
They are in the brainstem, 4 on each side, 2 for sensory and 2 for motor.
If you were to trip, and the sensation of falling to the side were sensed by the sensory vestibular nuclei in the brainstem, what would happen?
These sensory nuclei would signal the motor vestibular nuclei to send a signal down the vestibulospinal tract of the spine to LMN’s initiating involuntary movement of the “anti-gravity muscles”…and hopefully you don’t fall on your face. At the same time, a copy of what is intended is sent to the cerebellum along with the proprioceptive data that arrives via the dorsal spinocerebellar tract to tell the cerebellum what is actually happening. The deep cerebellar nuclei then send the signals back to the vestibular nuclei so corrections can be made.
Damage to the cerebellum generally causes ____ because it prevents the brain from making ____
Incoordination, mid-course corrections
The inability to carry out mid-course corrections or “measure” movements is known as ____
Dysmetria
If you display limb and hand/foot incoordination, you might have a problem with the ____ portion of the ____
Lateral, cerebellum
Medial damage to the cerebellum causes problems with ____ musculature
Medial
I can’t do the finger-to-nose test very smoothly at all with my left arm and hand.
Left lateral cerebellar damage
A pt can’t perform rapid alternating movements with his right arm and hand. This is called ____ and it would be associated with ____ damage in this pt.
Dysdiadochokinesis, right lateral cerebellar damage
Gate, balance, and eye movements would be affected by ____ cerebellar damage
Medial
People who walk very cautiously MIGHT have a problem with the ____ cerebellum
Medial
Eyes overshooting their intended targets is called ____ and is associated with ____ cerebellar damage
Dysmetria, medial
Rhythmic jerking of both eyes in one direction
Nystagmus, medial cerebellar problem
T/F The basal ganglia acts exclusively on the bulbospinal system.
FALSE. It acts on the corticospinal system. The cerebellum acts on both systems.
T/F Proprioceptive feedback plays an important roll with the basal ganglia
FALSE. It receives NO proprioceptive feedback from the muscles or joints.
T/F The basal ganlia has NO direct effect on the brainstem or spinal cord.
TRUE
The cardinal signs of basal ganglia disruption are:
Inability to initiate voluntary movements, or abnormal “quanities” of overall movements (too much, too little)
One possible sign of basal ganglia pathology is abnormal ____ at rest, also known as dystonia
Tone
The roll of ____ is to active UMN’s in the premotor cortex and suppress inappropriate UMN’s for the same movement module.
Basal ganglia
When you are at rest, what is responsible for limiting spontaneous electrical activity in the pre and primary cortex so that your limbs don’t move?
Basal ganglia
T/F “Extra-pyramidal” means anything pertaining to dysfunction associated with the basal gangia
TRUE
Where is the nuclei of the basal ganglia located?
Near the junction of the cerebrum and the midbrain with some actually lying within the structures themselves
This structure of the basal ganglia bulges into the lateral ventricles at the base of the cerebrum
Caudate nucleus
What are the 4 distinct categories of basal nuclei?
Input, output, intrinsic, modulatory
Which pathway of the basal ganglia has an intrinsic nucleus?
The indirect pathway
When the basal ganglia direct pathway is activated, it will induce ____
ACTION
When the basal ganglia indirect pathway is activated, it will induce ____
INACTION
What is responsible for channeling information into either the direct or indirect pathways of the basal ganglia?
The substantia nigra pars compacta
What is the modulatory nucleus of the basal ganglia?
The substantia nigra pars compacta
T/F The substantia nigra pars compacta determines whether there is movement or not…it’s pretty important.
TRUE
Basal ganglia input nuclei:
Caudate, putamen
Basal ganglia output nuclei:
Globus pallidus pars INTERNA, substantia nigra pars RETICULATA
Basal ganglia intrinsic nuclei:
Subthalamic, globus pallidus pars EXTERNA
Basal ganglia modulatory nuclei:
Substantia nigra pars COMPACTA
Damage to what (basal gangia nuclei type/s) causes hypokinesis?
Modulatory
The ____ basal ganglia nucleus receives input from the motor cortex, while the ____ basal ganglia nucleus receives input from the non-motor areas of the cortex
Putamen, caudate
The desire to execute an action originates in the cerebral cortex, which sends excitatory input to the ____ and ____ cortex as well as the ____
Pre motor, motor, basal ganglia
T/F Excitation messages or inhibition messages from the basal ganglia allow the motor cortex to send coordinated movement information to the target muscles.
TRUE
What neurotransmitter is associated with the substantia nigra pars compacta?
Dopamine
Parkinson’s disease affects what neurons in what cells?
The dopamine-containing cells of the substantia nigra pars compacta
What % of neurons in the affected area must Parkinson’s disease destroy before the pathology becomes clinically evident symptomatically?
80-85%
Bradykinesia, difficulty initiating movements, resting tremors in the fingers and hands, a “mask” like facial affect, stooping posture, and altered gait.
Parkinson’s disease
With PD, hypokinesia occurs. This is because the ____ basal ganglia pathway is favored?
Indirect
Huntington’s disease affects what nuclei of the basal ganglia?
Input. Caudate and Putamen
What % of neurons in the affected area must Huntington’s disease destroy before the pathology becomes clinically evident symptomatically?
50%
What are the “classic” movements associated with HD?
Chorea or “extra” and wild movements
The abnormal movements associated with HD are associated with in (increase/decrease) of inhibition of the output nuclei GPi
Decrease of inhibition meaning an increase in outgoing signals
Wild movements, explosive temper, impulsive behavior are possible S/S of ____
HD
T/F PD is a hypokinetic disorder and HD is a hyperkinetic disorder
TRUE
Violent movements of the limbs associated with CVA’s. This is thought to be associated with the death of what nuclei?
Ballismas, subthalamic
The basal ganglionic nuclei communicate with the (ipsilateral/contralateral) side motor cortex
Ipsilateral
T/F The neurons of the basal ganglia also communicate with areas of brain responsible for emotion, motivation, and cognition
TRUE
If someone has psychiatric symptoms, it is likely that: A) the cerebellum is damaged only B) the cerebellum and the basal gangia are damaged C) the basal ganglia alone is damaged D) B or C
D. Psychiatric S/S do not occur because of cerebellar damage alone. The cerebellum does not communicate with the areas of the brain responsible for emotions or cognition. Basal ganglia damage or other brain damage would have to have occurred.
Motor “learning” must involve the ____, ____, and the ____
Pre-motor cortex, cerebellum, basal ganglia
T/F Pre-motor cortex damage may cause clumsiness.
TRUE
Where does postural control take place?
Reticular formation in the brainstem
How is muscle tone regulated?
Via reflex arcs
Where does balance control take place?
In the vestibular nuclei of the brainstem
Where do motor neurons exist and where do they exit the spinal cord?
In the ventral horn grey matter, exiting out the ventral nerve roots
Rexed lamina 8 contains what?
Motor neurons
T/F Muscles receive somatic motor innervation only from the spinal cord segment of the same level.
FALSE
Two general types of motor neurons
Alpha and Gamma
UMN or LMN - weakness, spastic rigidity, hypertonia, hyperreflexia
UMN pathology.
UMN or LMN - weakness, flaccid paresis, paralysis, hypotonia, hyporeflexia, marked muscle atrophy, fasciculations
LMN
What makes up the corpus striatum?
Putamen and caudate nuclei
What are the caudate nuclei usually seen next to in a frontal plain image?
Lateral ventricles
Pars interna of the GP is an ____ nuclei
Output
Pars reticular of the SN is an ____ nuclei
Output
Pars extern of the GP is an ____ nuclei
Intrinsic
Subthalamic nuclei is an ____ nuclei
Intrinsic
The modulatory nuclei determines whether a pathway is direct or indirect. The nuclei responsible for this is the ____
Pars compacta of the SN
T/F The ALS and spinothalamic tracts are synonymous
TRUE
The Lissaurs tract is in the ____ matter and carries ____ info up or down one level of the spinal cord to allow synapsing in the lamina 2 or substantia gelatinosa in the dorsal horn. It then crosses the ____ and heads up.
White, ALS, anterior white commissure
What does the PAG release?
Pro-enkephalins
When the PAG stimulate the raphe, they release endorphins to (excite/inhibit) the ALS tract in that area.
Inhibit
What is the RAS system responsible for?
Arousal.
Severe damage to the RAS causes ____
Coma
T/F The RAS is basically in the pons/medulla area of the brainstem
TRUE
T/F If you see the red nuclei, this is a landmark for the rostral midbrain
TRUE
If you see “wine glass” features marking the inferior colliculi in cross section, you are in the ____
Caudal midbrain
T/F Capillary endothelial in the brain cells have tight junctions and NO fenestrations
TRUE
If capillary endothelial cells in the choroid plexus are “leaky”, what filters what get’s in and out of the CSF?
Choroid epithelial cells
Gadolinium shows up (dull/bright) on MMR
Bright
What drug can temporarily disrupt the BBB?
Mannitol
CSF serves 3 main functions…
Reduces weight, buggers pH, occupies space
Path of CSF is…
Created in the choroid plexus’ within each of the 4 ventricles. From the lateral ventricles, it travels through the interventricular foramen into the 3rd ventricle then through the cerebral aqueduct into the 4th ventricle.
CSF leaves the 4th ventricle through the two foramena ____ and the one medial foramen of ____
Luschka, Magendie
The CSF travels in the sub ____ space and ends up near the superior ____ sinus and leaves via arachnoid ____ into the superior ____ sinus and into the venous system
Sudarachnoid, sagittal, villa, sagital
CSF eventually enters the ____ jugular veins.
Internal
In the CSF you find increased RBC’s
Subarachnoid bleeding
In the CSF you find increased WBC’s
Immune or autoimmune problem
In the CSF you find increased protein levels
Capillary permeability issue = inflammation or tumor
In the CSF you find increased IgG’s
Plasma cell presence indicating brain infection or autoimmune problem
In the CSF you find decreased glucose levels
Bacterial infection
You see a cross section with some weird looking snakes in an olive type nuclei in the ventral portion. You are likely in the…
Rostral medulla
T/F The PAG is located in the Pons
FALSE. Midbrain surrounding the cerebral aqueduct
What would cause astereognosis?
Damage to the secondary somatosensory cortex. You can feel an object in your hand but can’t identify what the object is.
THIS IS THE END OF MY FLASHCARDS
SORRY THEY CAME SO LATE, I ONLY STARTED THEM YESTERDAY. DID MY BEST. HOPE IT HELPS:) Kisses, Corb
