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Neuro Block II Review
N/A
429
Anatomy
Graduate
03/24/2012

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Cards

Term
The Dorsal column-medial lemniscal system is responsible for what?
Definition
Fine touch, vibration, proprioception from arms, legs, and trunk
Term
What is the course of the dorsal column medial lemniscal tract?
Definition
Legs and lower trunk ascends in the fasciculus gracilis to terminate in the nucleus gracilis of the caudal medulla, upper trunk and arms aascend in the fasciculus cuneatus and temrinate in the nucleus cuneatus of the caudal medulla nad upper cervical spinal cord
Term
Nucleus gracilis and cuneatus project axons that cross to contralateral medulla and ascend via what tract?
Definition
Medial lemniscus
Term
Fibers of the medial lemniscus terminate in what location?
Definition
Ventral posterolateral nucleus (VPL) of the thalamus
Term
The ventral posterolateral nucleus projects axons relaying signals from the medial lemniscus to what?
Definition
Somatosensory cortex via the posterior limb of the internal capsule
Term
What is the function of the spinothalamic tract of the anterolateral system
Definition
Carries pain and temperature from arms, legs, and trunk
Term
Axons of the anterolateral system cross to the contralateral spinal cord via what?
Definition
Anterior white commissure
Term
Axons of the spinothalamic tract ascend the spinal cord via the anterolateral system and terminate in what structure?
Definition
Ventral posteriolateral nucleus (VPL) of the thalamus
Term
How are spinothalamic tract axons (via anterolateral system) relayed by the VPL of the thalamus?
Definition
Projects axons through the posterior limb of the itnernal capsule to reach the somatosensory cortex
Term
What are the two additional pain pathways that ascend as part of the atnerolateral system?
Definition
Spinoreticular tract and spinomesencephalic tract
Term
What is the function of the spinoreticular tract?
Definition
Carries pain and crude touch via the anterolateral system to brainstem reticular formation, part of the reticular activating system which projects to all regions of the cortex, is required for arousal of higher CNS centers
Term
What is the function of the trigeminothalamic system?
Definition
Works as three trigeminal nuclei that receive trigeminal afferents carrying sensation from three non-overlapping segments of the face
Term
Which trigeminal nucleus receives fine touch and vibration from the face via the three branches of the trigeminal nerve?
Definition
Pontine trigeminal nucleus
Term
The pontine trigeminal nucleus projects axons that cross contralaterally to join what?
Definition
Medial lemniscus
Term
Pontine trigeminal nucleus fibers project through the medial lemniscus and terminate in what structure?
Definition
Ventral posteromedial nuclues (VPM) of the thalamus
Term
Which trigeminal nucleus receives pain and temperature innervation from the face through the trigeminal, facial, glossopharyngeal, and vagus nerves?
Definition
Spinal trigeminal nucleus
Term
Spinal trigeminal nucleus fibers project axons that terminate in what structure?
Definition
Projects contralaterally to terminat in the ventral posteromedial nucleus (VPM) of the thalamus
Term
The mesencephalic trigeminal nucleus contains cell bodies of what nerve?
Definition
Axons of mandibular branch of the trigeminal nerve that carry proprioceptive input
Term
The mesencephalic trigeminal nucleus projects axons to what structure?
Definition
Trigeminal motor nucleus
Term
What is the function of the mesencephalic trigeminal nucleus?
Definition
Proprioception for muscles of mastication, reflex control of bites
Term
What is the function of the ventral posteromedial nucleus (VPM) of the thalamus?
Definition
Relays fine touch, pain, and temp from the controlateral face, projects axons via the genu of the internal capsule to reach somatosensory cortex
Term
Stimulation of projections of what nucleus can cause analgesia with little effect on tactile stimuli?
Definition
Medullary Raphe Magnus nuclei via enkaphalin interneurons in spinal cord posterior horn
Term
Nonspecific relay nuclei and intralaminar nuclei processes relay pain information from the reticulospinal tract to what areas?
Definition
Most areas of the cortex, including the cingulate gyrus and insular cortex of the limbic system (emotional pain)
Term
What constitutes a "lower motor neuron"?
Definition
Neurons with cell bodies in the brainstem and spinal cord that innervate muscles, receives input from sensory systems and upper motor neurons
Term
What constitutes a "upper motor neuron"?
Definition
Neurons with cell bodies in cortex and brainstem that project to lower motor neurons
Term
Damages to direct upper motor neurons causes what indicators?
Definition
Babinski sign and paresis/paralysis of voluntary movements, particularly fine skilled movements
Term
Damages to indirect upper motor neurons causes what indicators?
Definition
Paralysis, hyperreflexia, rigidity, anle clonus (deals with balance, posture, equilibrium, and gait)
Term
What are the inhibitory neurotransmitters for local interneurons within the spinal cord and brainstem?
Definition
Glycine and GABA
Term
Where do corticospinal tract fibers originate?
Definition
Pyramidal cells in frontal and parietal cortex
Term
Where do corticospinal tract fibers cross over to the other side?
Definition
At the pyramidal decussation (between medulla and spinal cord)
Term
What is the function of the corticospinal tract?
Definition
Voluntary movement, particularly in distal extremities
Term
A lesion of the lateral convexity of the cortex would produce what signs?
Definition
Paralysis and sensory loss of contralateral lower face
Term
A lesion of the medial cortex would produce what signs?
Definition
Paralysis and sensory loss of contralateral leg
Term
A lesion of the genu of the internal capsule will produce what signs?
Definition
Motor paralysis of the contralateral lower face and sensory loss of the contralateral face
Term
A lesion of the posterior limb of the internal capsule will produce what signs?
Definition
Paralysis and sensory loss in contralateral leg
Term
A lesion in the midbrain cerebral peduncle will produce what signs?
Definition
Paralysis of contralateral leg, arm, tongue, lower face, and ipsilateral eye
Term
A lesion of the pontine base would produce what signs?
Definition
Paralysis of the contralateral leg, arm, tongue, and ipsilateral eye on lateral gaze
Term
A lesion of the medial medulla produces what signs?
Definition
Paralysis of contrlateral leg, arm, and ipsilateral tongue, sensory loss of sensation in contralateral body
Term
A spinal cord hemisection produces what signs?
Definition
Spastic paralysis of ipsilateral body below lesion, flaccid paralysis of ipsilateral body at level of lesion, loss of discriminative sensation in ipsilateral body below lesion, loss of pain sensation in contralateral body below lesion
Term
Where does the corticobulbar tract originate?
Definition
Pyramidal cells in frontal and parietal cortex
Term
What course does the corticobulbar tract follow?
Definition
Passes through corona radiata, genu of internal capsule, and cerebral peduncle alongside corticospinal tract
Term
What is the function of the corticobulbar tract?
Definition
Axons bilaterally innervate lower motor neurons in the brainstem (excluding the lower face and CN VII). Controls voluntary movement involving muscles of head and neck
Term
Are corticobulbar fibers in the facial nerve contralateral, ipsilateral, or bilateral in their distribution?
Definition
Contralateral, all others by the corticobulbar tract are bilateral
Term
Where does the rubrospinal tract originate?
Definition
Red nucleus in the midbrain
Term
What is the function of the rubrospinal tract?
Definition
Facilitates flexor musculature for skilled voluntary movement in the arm
Term
Where does the lateral vestibulospinal tract originate?
Definition
Lateral vestibular nucleus in the medulla
Term
What is the function of the vestibulospinal tract?
Definition
Facilitates extensor musculature by inhibiting flexors, also controls trunk musculature and involved with posture and is involved with posture and equilibrium
Term
Where does the medial vestibulospinal tract originate?
Definition
Medial vestibular nucleus in the medulla
Term
What do the vestibulospinal tracts occupy as they descend the spinal cord?
Definition
Anterior funiculus
Term
Which vestibulospinal tract is ipsilateral and which is bilateral?
Definition
Lateral is ipsilateral, medial is bilateral
Term
What is the function of the medial vestibulospinal tract?
Definition
Follows medial longitudinal fasciculus and mediates reflexes of the vestibular system including eye movement and positioning of the head and neck
Term
Which reticulospinal tract is ipsilateral and which is bilateral?
Definition
Medial reticulospinal tract is ipsilateral and lateral reticulospinal tract is bilateral
Term
What is the function of the medial reticulospinal tract? Where does it originate?
Definition
Originates in the pontine reticular nuclei, facilitates posture and anti-gravity extensor muscle tone
Term
What is the function of the lateral reticulospinal tract? Where does it originate?
Definition
Originates in medullary pontine nucleus, inhibits posture and anti-gravity extensor muscle tone, facilitates flexor muscle tone
Term
Where does the lateral tectospinal tract originate?
Definition
Tectum of the midbrain
Term
What is the function of the lateral tectospinal tract?
Definition
Pupillary (dilation) reflex to darkening mediated by sympathetic nervous system (bilateral)
Term
Where does the medial tectospinal tract originate?
Definition
Superior colliculus
Term
What is the function of the medial tectospinal tract?
Definition
Reflex orienting movements of the head and neck (contralateral)
Term
What overarching structures make up the basal ganglia?
Definition
Corpus striatum (telencephalic origin), subthalamic nucleus (diencephalic origin), substantia nigra (mesencephalic origin)
Term
What makes up the corpus striatum?
Definition
Striatum (caudate & putamen), globus pallidus, lentiform nucleus
Term
What is the general function of the basal ganglia?
Definition
Plan, initiate, and maintain voluntary motor activities, regulates eye movements, cognitive and emotional functions, and procedural learning
Term
What is akinesia?
Definition
Lack of movement or an inability to initiate movement (can be due to basal ganglia damage)
Term
What is bradykinesia?
Definition
Abnormally slowing of movement (can be due to basal ganglia damage)
Term
What is micrographia?
Definition
Decrease of handwriting size, an early expression of bradykinesia (can be due to basal ganglia damage)
Term
What is rigidity?
Definition
Increased continuous resistance to passive movement (can be due to basal ganglia damage)
Term
What is chorea?
Definition
Involuntary continuous body movement (can be due to basal ganglia damage)
Term
What is athetosis?
Definition
Slow, purposeless movement such as lip smacking (sign of basal ganglia damage)
Term
What is dystonia?
Definition
Persistent form of one movement of athetosis resulting in sustained muscle contraction producing postural abnormality (sign of basal ganglia damage)
Term
What is ballismus?
Definition
Violent flinging of the limb or limbs (sign of basal ganglia damage)
Term
What is dyskinesia?
Definition
A general term including resting tremors, athetosis, chora, and ballismus (signs of basal ganglia damage)
Term
What is the excitatory neurotransmitter to the basal ganglia?
Definition
Glutamate
Term
Input to the basal ganglia is between what structures?
Definition
Cortex (motor functions) to neostriatum
Term
What is the inhibitory neurotransmitter output by the basal ganglia?
Definition
GABA
Term
Output from the basal ganglia originates from what structures?
Definition
Substantia nigra, pars reticulata, and globus pallidus internus
Term
Which pathway of the basal ganglia increases cortical activity? Which decreases?
Definition
Direct pathway increases, indirect pathway decreases
Term
Striatal medium spiny projections of neurons of direct pathways in the basal ganglia couple GABA withw hat?
Definition
Substance P
Term
Striatal medium spiny projections of neurons of indirect pathways in the basal ganglia couple GABA withw hat?
Definition
Enkephalin
Term
What part of the basal ganglia receives glutamate as a neurotransmitter and from where?
Definition
Caudate and putamen from the cortex
Term
What is the only non-GABAergic nucleus within thebasal ganglia? What does it send projections to?
Definition
Subthalamic nucleus, projects to substantia nigra, pars reticulata, and globus pallidus internus
Term
What parts of the basal ganglia use dopamine as a neurotransmitter in its projections? What is the target of those axons?
Definition
Substantia nigra and pars compacta, projects to striatum via nigrostriatal pathway
Term
Which dopaminergic pathways in the basal ganglia is excitatory? Which is inhibitory?
Definition
Substantia nigra and pars compacta project to striatm, direct pathway is excitatory, indirect pathway is inhibitory
Term
Degeneration of dopaminergic neurons of the substantia nigra pars compacta leads to what?
Definition
Parkinson's disease
Term
Where is acetylcholine found as a neurotransmitter within the basal ganglia? Abnormalities are related to what condition?
Definition
In large aspiny striatal interneurons, imbalances linked to Huntington disease
Term
In hyperkinetic disorders, basal ganglia balance shifts toward which pathway?
Definition
Direct pathway (inhibition is reduced)
Term
In hypokinetic disorders, basal ganglia balance shifts toward which pathway?
Definition
Indirect pathway (inhibition is increased)
Term
The anterior lobe of the cerebellum is involved in what tasks?
Definition
Posture, muscle tone, lower limb coordination
Term
The posterior lobe of the cerebellum is involved in what tasks
Definition
Maintaining posture and muscle tone in the trunk and distal extremities
Term
The flocculonodular lobe of the cerebellum is involved in what tasks?
Definition
Maintaining balance and eye movements related to the vestibulo-ocular reflex
Term
The vermis of the cerebellar cortex serves what function?
Definition
Receives proprioceptive inputs from ipsilateral body and from contralateral motor cortex, coordinates musculature of head and face and axial musculature through medial reticulospinal and vestibulospinal tracts
Term
The intermediate zone of the cerebellar cortex is responsible for what functions?
Definition
Receives proprioceptive inputs from ipsilateral body and contralateral motor cortex, controls distal limb musculature, posture, balance, and locomotion through lateral reticulospinal and vestibulospinal tracts
Term
The lateral hemispheres of the cerebellum is involved in what tasks?
Definition
Planning of spatial and temporal aspects of voluntary movement
Term
What cell fibers in the cerebellum are excitatory?
Definition
Mossy and climbing fibers
Term
What cell types are excitatory in the cerebellum?
Definition
Granule and brush cells
Term
What cell types in the cerebellum are inhibitory?
Definition
Purkinje, golgi, basket, stellate, and nuclear cells
Term
Motor deficits of patients with cerebellar lesions are expressed through what tract?
Definition
Corticospinal tract
Term
Cerebellar cortex and nuclei are supplied mainly by what artery?
Definition
Superior cerebellar artery
Term
Posterior and anterior inferior cerebellar arteries supply what part of the cerebellum?
Definition
Cortex
Term
Are cerebellar lesions expressed contralaterally, ipsilaterally, or bilaterally?
Definition
Ipsilateral
Term
Bilateral expression of cerebellar lesions usually involve to what portion of the cerebellum?
Definition
Midline lesions of the vermis and fastigial nucleus
Term
Damage to the oculomotor nerve would produce what signs?
Definition
Mydriasis (pupil dilation), ptosis (eyelid droop_, eye down and out
Term
Damage to the trochlear nerve produces what signs?
Definition
Diplopia when gaze directed inferior and medial, paralysis of the superior oblique, head tilted to align with "good eye"
Term
Lower motor neuron damage to the trigeminal nerve would produce what signs?
Definition
Unilateral bite weakness
Term
Upper motor neuron damage to the trigeminal nerve would produce what signs?
Definition
Minimal effect due to bilateral cortical innervation
Term
Damage to the abducens nerve would produce what signs?
Definition
Paralysis of the lateral rectus muscle, inability to gaze laterally with possible medial deviation of affected eye. Peripheral nerve damage affects ipsilateral eye while damage to the nucleus paralyzes lateral gaze bilaterally
Term
What causes Bell's palsy?
Definition
Damage to the facial nerve
Term
What are signs of Bell's palsy?
Definition
Paralysis of ipsilateral face, loss of salivation and tearing, lost of taste in anterior two thirds of tongue, hyper acusis, however contralateral forehead is unaffected
Term
Damage to the cochlea portion of the vestibulocochlear nerve results in what signs?
Definition
Loss of pure tonal hearing
Term
Damage to the labyrinth portion of the vestibulocochlear nerve results in what signs?
Definition
Vertigo and nystagmus
Term
Damage to the whole vestibulocochlear nerve results in what signs?
Definition
Tinnitus, high frequency hearing loss, difficulty with speech comprehension, loss of stapedial reflex, vertigo with nystagmus
Term
Lower motor neuron damage of the glossopharyngeal nerve exhibits what signs?
Definition
Dysarthria, dysphagia, ipsilateral loss of gag reflex, may involve vagus nerve
Term
Upper motor neuron damage of the glossopharyngeal and vagus nerves shows what symptoms?
Definition
Little effect due to bilateral cortical control
Term
Damage to the lower motor neurons of the vagus nerve have what effects?
Definition
Dysarthria, dysphagia, ipsilateral loss of gag reflex, may involve glossopharyngeal nerve
Term
Bilateral lesion of the vagus nerve has what consequences?
Definition
Death
Term
Damage to the spinal accessory produces what symptoms?
Definition
Difficulty in turning head to contralateral side with ipsilateral shoulder droop
Term
Lesion of the hypoglossal nerve produces what signs?
Definition
Tongue deviates to side of lesion (damage to nucleus deviates to contralateral side)
Term
What tracts and nuclei in the medulla are affected by an infarction of the posterior inferior cerebellar artery or vertebral artery?
Definition
Spinal trigeminal, spinothalamic, nucleus ambiguus, descending sympathetic control, vestibular nucleus, cerebellum
Term
What tracts and nuclei in the medulla are damaged by infarction of the anterior spinal artery or basilar artery?
Definition
Corticospinal tracts within medullary pyramids, medial lemniscus, hypoglossal nucleus and nerve
Term
Infarction of the penetrating branches of the basilar artery can damage what structures in the basal pons?
Definition
Corticospinal tracts and descending cortical control of brainstem upper motor neurons, damage to the abducens nerve
Term
What structures in the dorsal pons can be damaged due to infarction of the penetrating branches of the basilar artery?
Definition
Facial motor nucleus, abducens, lateral gaze center, medial lemniscus, spinothalamic tract, main trigeminal nucleus, descending spinal trigeminal tract
Term
What sites int he midbrain would be damaged by an infarction of the posterior cerebral artery?
Definition
Cerebral peduncles containing corticospinal tracts and descending cortical control of brainstem upper motor neurons, oculomotor nerve
Term
Compression of the posterior midbrain or a tectal infarction would damage what structures in the midbrain?
Definition
Vertical gaze center, vergence center, posterior commissure and textum
Term
The diencephalon is derived from what embryonic structure?
Definition
Prosencephalon
Term
The sulcus limitans separates the diencephalon to form what structures?
Definition
Dorsal thalamus vie alar & roof plats and basal plate derived hypothalamus
Term
The caudal roof plate of the thalamus develops to form what?
Definition
Epiphysis which forms the pineal gland
Term
What makes up the epithalamus?
Definition
Haenular nuclei, stria medullaris, and pineal gland
Term
The choroid plexus of the diencephalon develops from what embryonic structure?
Definition
Roof plate and specialized ependymal areas known as circumventricular organs (lack blood brain barriers)
Term
What gives rise to the neurohypophysis (posterior lobe of pituitary) and the infundibulum?
Definition
Diencephalon
Term
The posterior diencephalon forms what structures/
Definition
Subthalamic nucleus and zona incerta, forming the subthalamus
Term
What are the divisions of the adult diencephalon?
Definition
Dorsal thalamus, hypothalamus, epithalamus, and subthalamus
Term
All but what sensory information is processed by the thalamus?
Definition
All but olfaction
Term
The white matter covering the dorsal thalamus is known as what?
Definition
Statum zonale
Term
The Lateral thalamus under the reticular nucleus is covered by what?
Definition
External medullary lamina
Term
What does the internal medullary lamina divide the thalamus into?
Definition
Internally divides thalamus into groups of nuclei - primary anterior, medial, lateral, and interlaminar groups
Term
What group of nuclei in the thalamus borders the lateral ventricles?
Definition
Anterior nuclear group
Term
The lateral groups in the thalamus is further divided into what?
Definition
Dorsal and ventral tiers
Term
What is included in the dorsal tier of the thaalmus?
Definition
Lateral dorsal and lateral posterior intralaminar groups, and the pulvinar
Term
What is included int he ventral tier in the thalamus?
Definition
Ventral lateral and ventral posterior intralaminar groups
Term
What are included in the intralaminar nuclei?
Definition
Centromedian and parafascicular nicleu along with several smaller nuclei surrounded by the internal medullary lamina
Term
What makes up the metathalamus?
Definition
Medial and lateral geniculate bodies
Term
The medial and lateral geniculate are part of what sensory systems?
Definition
Medial geniculate = auditory, lateral = visual
Term
What thin sheet of neurons lies beyond the external medullary lamina adjacent to the internal capsul?
Definition
Reticular nucleus
Term
Zona incerta of the subthalamus is an extension of what structure?
Definition
Reticular formation
Term
The subthalamus contains basal ganglia projections in what?
Definition
Prerubal fields of Forel
Term
What is the pineal gland associated with?
Definition
Circadian rhythms
Term
The habenular nuclei receive basal ganglia information through what? What do they project to?
Definition
Stria medullaris, projects to interpedunculat nucleus of the midbrain
Term
What sort of information is the habenular nucleus associated with?
Definition
Emotional related facial expression
Term
What is the blood supply to the hypothalamus and subthalamus?
Definition
Circle of Willis via perforating branches, the rest of the thalamus is supplied by branches of the posterior cerebral artery
Term
Rostral thalamus is supplied by what?
Definition
Thalamoperforating arteries
Term
Posterior and lateral regions are supplied by what?
Definition
Posterior choroidal and thalamogeniculate arteries
Term
The medial areas of the thalamus near the third ventricle are supplied by what?
Definition
Posterior choroidal arteries
Term
The geniculate bodies are supplied by what?
Definition
Thalamogeniculate arteries
Term
The anterior nuclear group of the thalamus is associate with what?
Definition
Memory processing from the hippocampus via the mammillary bodies via the mammilothalamic fasciculus
Term
What are the two parts of the ventral anterior nuclear group of the thalamus?
Definition
Magnocellular part with connections to the reticular formation and a parvocellular part that receives input from the medial globus pallidus and projects to motor areas and the frontal lobe
Term
What are the two parts of the ventral lateral nucleus?
Definition
Anterior (oral) part with similar connections as the VA with the globus pallidus, and a posterior part that connects with the cerebellum
Term
What part of the thalamus is associated with the pathway for conscious perception of sensation?
Definition
Ventral posterior nucleus of the thalamus, areas are somatotopically organized
Term
What is the function of the pulvinar?
Definition
Acts as part of the extrageniculate visual pathway related to the localization of objects in space, independent of their form. Receives and projects to visual association areas
Term
The dorsomedial nucleus of the thalamus is associated with what processes?
Definition
Limbic associations and receives inputs from the amygdala, bilateral lesions of its projections are similar to a prefrontal lobotomy with loss of judgement and foresight but also relief of anxiety states and the distress of pain
Term
The lateral geniculate receives axons from what cells? How are those axons organized?
Definition
Retinal ganglion cells, crossed axons end in layer 1, 4, 6, uncrossed end in 2, 3, 5
Term
The anterior radiation is primarily the anterior limb of the internal capsule and is mostly associated with the connection of what?
Definition
Dorsomedial nucleus to prefrontal cortex
Term
The middle or superior radiation is in the posterior limb of the internal capsule and contains somatosensory information from what?
Definition
VP nucleus, associated connections with parietal lobe and VA and VL to motor areas
Term
What is found in the posterior radiation?
Definition
Geniculocalcarine tract including Meyer's loop and pulvinar connections to the occipital lobe
Term
The inferior radiation contains connections with what?
Definition
Temporal lobes, particularly the auditory radiations
Term
Ia and Ib refers to what category of axons?
Definition
Motor afferent sensory fibers, fast conducting
Term
II refers to what category of axons?
Definition
Some motor afferent, sensory fibers for epicritic sensations, intermediate velocity
Term
III, IIIB refers to what category of axons?
Definition
Sensory afferents associated with fast pain, sympathetic nerves, moderately slow conducting
Term
IV and IVC refers to what category of axons?
Definition
Protopathic afferents, slow pain, temp, mechanoreceptors
Term
Which is faster, alpha or gamma motor neurons?
Definition
Alpha
Term
What nerves are used in the lower limb for measuring conduction velocities?
Definition
Tibial or peroneal nerves for motor, sural nerve for sensory
Term
Central connections of nerves can be evaluated by measuring what?
Definition
H wave(central reflex response to a muscle contraction from nerve stimulation)
Term
What is fibrillation?
Definition
Spontaneous contraction of individual muscle fibers within motor units after denervation?
Term
What are fasciculations?
Definition
Contractions of entire motor units
Term
What are positive sharp waves and polyphasic potentials?
Definition
Spontaneous activities of muscle that can be observed with reinnervation and reflect changes in the electrical properties of muscle with denervation
Term
What kind of myogenic activity are EOG and ENGs meant to evaluate?
Definition
Eye muscles, typically in sleep studies or to evaluate nystagmus
Term
What does an EEG measure?
Definition
The average electrical activity of the brain (primarily cortex) by measuring the changes in the electrical potential between two areas on the scalp
Term
How are EEG results interpreted?
Definition
Higher voltages = synchronous firing of neurons, lower voltages = asynchronous firing
Term
EEG is used to evaluate for what diseases?
Definition
Epilepsy, brain tumors, periods of unconsciousness, dementia, overall level of brain trauma, brain death, etc.
Term
Beta activity on an EEG is defined as what?
Definition
14-60Hz, associated with normal waking activity, active attention, typically low voltage fast waves
Term
Alpha rhythm on an EEG is defined as what?
Definition
8-13Hz, reflexted a relaxed alert state, higher voltage slower waves
Term
Theta rhythm on an EEG is defined as what?
Definition
4-7Hz, associated with drowsiness, childhood to young adults, can be induced with hyperventilation, seen during daydreams, higher voltage slow waves
Term
Delta waves on an EEG is defined as what?
Definition
under 3Hz, high voltage slow waves, present in NREM sleep, young children, can be pathological
Term
Somatosensory Evoked Potentials (SSEPs) in EEGs are used to detect what?
Definition
Continuity of sensory pathways, typically from peripheral nerves
Term
Visual Evoked Potentials (VEPs) in EEGs are used to evaluate what?
Definition
Visual pathways, particularly where the patient is incapable of responding (hysterical blindness, infants, coma)
Term
Brainstem Auditory Evoked Responses (BAERs) in EEGs are used to evaluate what?
Definition
Auditory pathways
Term
What is magnetoencephalography?
Definition
Detection of the magnetic waves associated with brain activity, can be used to more reliably localize electrical activity compared to EEGs
Term
What is the function of the medullary raphe nuclei?
Definition
Regulation of sensory information
Term
Stimulation of projections of raphe nuclei at the periaqueductal grey produces what effect?
Definition
Long lasting inhibition of pain. Opiate antagonists can block the stimulation induced analgesia
Term
The paramedian pontine reticular formation is the best example of what?
Definition
The central nuclear group of the reticular formation that are associated with eye movements, coordinates horizontal and vertical eye movements via CN III
Term
What maintains the conscious state and desynchronize the EEG?
Definition
The ascending reticular arousal system (ARAS)
Term
The medullary parvocellular area contains nuclei that regulates what?
Definition
Respiration, cardiac cycle, and blood pressure. Respiratory nuclei includes the parabranchial complex and the Kiliker-Fuse nuclei, regulates respiratory rhythm
Term
What is the primary nuclear group that regulates respiration?
Definition
Superficial medullary neurons, the dorsal respiratory group, and the ventral respiratory group
Term
Of the superficial medullary neuronal groups that mediate respiration, which is the "inspiratory are"?
Definition
Dorsal respiratory group - the lateral region of the solitary nucleus that integrates respiratory sensory information
Term
What is the function of the ventral respiratory group?
Definition
Projects from C1 to caudal pons, excitatory to phrenic and thoracolumbar motor neurons associated with respiration
Term
What part of the ventral respiratory group inhibits respiratory motor neurons?
Definition
Botzinger complex of nuclei
Term
What is the primary regulator of the ventral respiratory group (though does not generate a respiratory rhythm)?
Definition
Kolliker-Fuse nuclei
Term
Where is the sensory input integration center for cardiovascular influences found?
Definition
Integrated by medial solitary nucleus at the level of CN IX and X, regulates heart rate and blood pressure
Term
What major rostrally projecting catecholaminergic nucleus plays an important role in sleep mechanisms?
Definition
Locus coeruleus (A6)
Term
What is the most prominent cholinergic nuclei of the brainstem and what is its function?
Definition
Pedunculopontine nucleus, receives and projects inputs to the basal ganglia and central nuclear groups, generates locomotor patterns
Term
Muscle spindles respond to what type of stimulation?
Definition
Muscle stretch and detection of muscle length
Term
Golgi tendon organs respond to what type of stimulation?
Definition
Located within tendons and responds to strong muscle contraction, detects muscle tension
Term
Pascinian corpuscles detect what?
Definition
Vibration, position sense
Term
Consciousness is dependent on what?
Definition
Connections between cerebral cortex and the ascending reticular arousal system (ARAS)
Term
Where does the ARAS originate?
Definition
Central nuclear group of the reticular formation, projects to the non-specific thalamic nuclei and zona incerta to broad areas of cerebral cortex
Term
Descending pathways from what structure regulates activity of central nuclear groups into circadian cycles of arousal?
Definition
Hypothalamus
Term
Norepinephrine is an important neurotransmitter in what reticular formation structure?
Definition
Locus coeruleus, active during the waking state
Term
Serotonin is an important neurotransmitter in what reticular formation structure?
Definition
Rostrally projecting raphe nuclei, most active during motor activity
Term
Acetylcholine is an important neurotransmitter in what reticular formation structure?
Definition
Nuclei in the upper pons and basal forebrain, active in the waking state and REM sleep
Term
Histamine is an important neurotransmitter in what reticular formation structure?
Definition
Tuberomammillary nucleus, activity is required for the waking state
Term
Orexin is an important neurotransmitter in what reticular formation structure?
Definition
A peptide neurotransmitter from several hypothalamic nuclei used by the hypothalamus partly to control sleep cycles, promotes activation of wakefullness
Term
They hypothalamus uses what neurotransmitter for inhibitory control over ARAS?
Definition
GABA
Term
What does orexin promote in the sleep cycle? What controls the circadian variation of the neurons that employ orexin?
Definition
Ventrolateral preoptic nucleus
Term
What are the two primary physiological states of sleep?
Definition
NREM and REM, distinction is made primarily on the basis of EEG activity
Term
What is the primary pattern of non REM sleep?
Definition
4 stages from desynchonized to synchronized pattern
Term
What does the waking activity look like on an EEG?
Definition
Beta wave patterns going to drowsy but alpha waves (alert)
Term
What occurs during stage I (drowsy stage) of sleep?
Definition
Moves to theta wave patterns characterizing a full stage I, easy to awaken
Term
What occurs during stage II of the sleep cycle?
Definition
10 to 15 CPS oscillations characterized by sleep spindles and other special wave forms
Term
What occurs during stage III and IV of the sleep cycle?
Definition
Slow waves, delta or deep sleep difficult to awaken, high voltage low wave activity
Term
How is REM characterized by EEG?
Definition
Desynchronized EEG similar to beta activity, spontaneous eye movements and activity in visual systems
Term
Stimulation of genital erectile tissue is a feature of what kind of sleep?
Definition
REM sleep
Term
NREM and NREM sleep cycles occur in what time intervals?
Definition
90-100 minutes
Term
What nuclei in the hypothalamus controls the sleep cycle?
Definition
Ventrolateral preoptic (VPO) nucleus
Term
What action does the ventrolateral preoptic nucleus perform in order to generate sleep?
Definition
GABA containing neurons in the VPO inhibit histamine output from the tuberomammilary nucleus, also inhibits projecting ascending system of Ach, NE, and serotonin, decreases activity of ARAS
Term
REM sleep is halted by the activation of what neurotransmitter systems?
Definition
Serotonin and norepinephrine
Term
Insomnia in elderly individuals may be related to a decrease in what?
Definition
Synthesis of melatonin, possibly related to calcification of the pineal gland
Term
What are the consequences of sleep dept?
Definition
Can impair diverse cognitive processes, produce mood swings, hallucinations, and increased susceptibility to seizures
Term
Sleep apnea is most common among what demographic?
Definition
Obese middle aged males due to decreased muscle tone in the muscles of the pharynx leading to decreased respiration
Term
What causes restless legs syndrome?
Definition
A sensory-motor disorder, can be treated via elimination of stimulants, relaxation techniques, and dopaminergic agonists
Term
What is cataplexy?
Definition
A sudden onset of the characteristics of sleep paralysis from a fully conscious state, may accompany narcolepsy
Term
Nacrolepsy and cataplexy are genetic related alterations of what?
Definition
Orexin containing neurons or their receptors
Term
Parasomnia is a broad term that includes what?
Definition
Disturbances such as walking, talking, or screaming during sleep, associated with NREM stages or transitions to REM
Term
Somnambulism (sleep walking) is most frequent in youth and usually occurs during which NREM stage?
Definition
NREM stage IV
Term
Sleep terrors are most commonly associated with children and usually begin in what stages of NREM sleep?
Definition
NREM stages III to IV
Term
Brain metabolism is based almost entirely on the oxidation of what?
Definition
Glucose oxidized to CO2
Term
Minor amounts of glucose are used in what processes?
Definition
Anaerobic glycolysis, production of glycoproteins and glycolipids, synthesis of neurotransmitters glutamate, GABA, and acetylcholine
Term
What is the majority (50-60%) of glucose metabolism used for in the brain?
Definition
Maintenance of membrane potentials, primarily via Na/K ATPase pumps
Term
Slightly less than half (~40%) of glucose metabolism has what function in the brain?
Definition
Basic cellular metabolism not related to functional activity
Term
What is the result of a disruption in glycolytic energy stores?
Definition
Slow depolarization of membranes bringing them closer to threshold, increasing sensitivity (leads to seizures)
Term
What cells form the major interface for metabolic processing of glucose in the brain?
Definition
Astrocytes
Term
How do astrocytes interact with glucose?
Definition
Responsible for the transfer of glucose from the blood to neurons, form the primary brain reservoir for glycogen
Term
What compound is used to monitor glucose uptake in the brain through the use of PET scans?
Definition
2-deoxyglucose labelled with 18-Flourine
Term
In the absence of glucose, what alternative metabolic precursor acts as a carbohydrate source that can be utilized for energy?
Definition
Mannose, though levels are usually low and it is absorbed slower than glucose
Term
Starvation, diabetes, and low carbohydrate diets may induce the use of what other alternative energy source?
Definition
Ketone bodies and free fatty acids from lipid metabolism, acetone is primary byproduct
Term
What stimulates the release of lactate at the synaptic junction by astrocytes?
Definition
Glutamate
Term
What is the primary regulator of cerebral blood flow?
Definition
Via tone of vascular smooth muscle controlled primarily by autoregulatory mechanisms and mediators (though there is some innervation as well)
Term
The majority (~2/3) of vascular resistance is attributed to what structures in cerebral blood flow?
Definition
Pial vessels via smooth muscle regulation
Term
The major homeostatic mechanisms regulating cerebral circulation are what?
Definition
Metabolic, myogenic, neurogenic
Term
Under normal circumstances, cerebral blood flow is directly coupled with what homeostatic mechanism?
Definition
Metabolism - increased neuronal activity is accompanied by vasodilation and increased blood flow via metabolic adenosine, NO, and CO2 levels
Term
NO modulates cerebral vessels particularly in the release of what neurotransmitter?
Definition
Glutamate
Term
Some autoregulatory mechanisms, particularly in intracerebral arterioles, are mediated by what cells?
Definition
Astrocytes via coupling through gap junctions and their cellular domains
Term
What is the most potent physiologic cerebral vasodilator, capable of initiating changes in seconds?
Definition
CO2 rapid crossing the blood-brain barrier
Term
Why does a rapid increase in CO2 cause vasodilation?
Definition
Reduction in pH of the perivascular fluid leads to vsodilation, possibly through NO and prostaglandin mediated mechanisms
Term
Hypercapnia means what?
Definition
Increased CO2 -> vessels dilate
Term
Hypocapnia means what?
Definition
Decreased CO2 -> vessels constrict
Term
How does the cerebral vessel response to increased oxygen (hypoxemia) differ from hypercapnia?
Definition
Much slower vasodilation response, is independent of baroreceptors and chemoreceptors
Term
The tight relationship between metabolism to blood flow (observable via MRI and other imaging methods) implies what relationship?
Definition
Blood flow increases reflect neural activity
Term
What is the primary myogenic mechanism that impacts cerebral blood flow?
Definition
Arterial blood pressure
Term
What is the most abundant perivascular neurotransmitter?
Definition
Acetylcholine
Term
What effect does hypothermia have on cerebral circulation?
Definition
Reduces cerebral oxygen metabolism and blood flow at a rate of 5-7% per degree Celsius.
Term
When is cerebral perfusion pressure regulated?
Definition
Never, except in cases of brain trauma, disease, or hypertension
Term
What is the anatomical basis for the blood brain barrier?
Definition
Capillary endothelial cells and their tight junctions, perviascular cells, a basement membrane, and astrocyte processes
Term
What is the most significant antomical basis for the blood brain barrier?
Definition
Capillary endothelial cells in brain tissue
Term
Who do capillaries found in the brain differ from capillaries seen elsewhere in the body?
Definition
Contains endothelial cells with tight junctions between them and much more restrictive system transport.
Term
What substances are freely allowed through the blood brain barrier?
Definition
Gases, lipid soluble substances, and water pass freely, electrolytes and glucose pass slowly and are often transport mediated
Term
What substances are barred from passed the blood brain barrier?
Definition
Plasma proteins and large organic molecules
Term
Why is the fetus or newborn susceptible to CNS effects of drugs that would not normally effect adults?
Definition
Blood brain barrier is not fully developed
Term
What factors are capable of altering the blood brain barrier?
Definition
Direct trauma, chemical toxins, tumors, severe hypertension, sever hypercapnia
Term
What are the consequences of a disrupted blood brain barrier?
Definition
Cerebral edema, disrupted ionic balance, may require slow functional recovery
Term
Do brain tumors have a blood brain barrier?
Definition
Frequently do not, though slow growing tumors may keep it intact
Term
The term stroke, or cerebrovascular accident, refers to what?
Definition
A sudden focal neurological syndrom resulting from cerebrovascular disease
Term
How is stroke generally characterized?
Definition
Sudden onset with subsequent recovery of brain function occurring gradually and to a varying degree
Term
What are general pathological processes that affect cerebral vasculature and may lead to a stroke?
Definition
Occlusion of the vessel lumen, vessel rupture, altered vessel wall permeability, changes in the viscosity or quality of blood that affect blood flow
Term
What are nonmodifiable risk factors for stroke?
Definition
Age, ethnicity, gender, family history, genetics
Term
What are modifiable risk factors for stroke?
Definition
Arterial hypertension, transient ischemic attacks, prior stroke, asymptomatic carotid bruit/stenosis, cardiac disease, aortic arch atheromatosis, diabetes mellitus, dysplipidemia, smoking, alcohol, oral contraceptives, obesity
Term
How long does it take for interruption of cerebral blood flow to suppress/reduce brain electrical activity?
Definition
12-15s
Term
How long does it take for interruption of cerebral blood flow to inhibit synaptic excitability of cortical neurons?
Definition
2-4 minutes
Term
How long does it take for interruption of cerebral blood flow to inhibit electrical excitability altogether?
Definition
4-6 minutes
Term
The point following the inhibition of electrical excitability due to cerebral ischemia is known as what?
Definition
Threshold of membrane failure
Term
What is the pattern of ischemia caused by a stroke? Why does it exhibit a pattern?
Definition
A core of lost tissue surrounded by a penumbra of ischemic tissue, due to strokes producing reduced cerebral blood flow to some areas and complete loss to others
Term
The area of reduced blood flow in a stroke is known as what?
Definition
Ischemic penumbra or area of misery perfusion. Lies somewhere between thresholds of cell dysfunction and cell death
Term
An occlusive stroke is defined as what?
Definition
Most common form of stroke, is due to closure of a blood vessel following embolism, thrombosis, or small vessel disease
Term
A hemorrhagic stroke is defined as what?
Definition
Stroke due to bleeding from a vessel caused by hypertension, aneurysm, or atreriovenous malformation
Term
What defines a cerebral embolism?
Definition
Occlusion of a cerebral vessel by some exogenous material traveling within the vessel, most commonly a thrombus (blood clot)
Term
What is most commonly occluded in the anterior circulation?
Definition
Superficial branches of the middle cerebral artery
Term
What is most commonly occluded in the posterior (vertebrobasilar) circulation?
Definition
Cerebellar or posterior cerebellar artery
Term
What is the progression of damage due to an embolus?
Definition
Ischemia (localized anemia) -> infarcation (vascular insufficiency causing necrosis)
Term
Atherosclerosis affects what arteries?
Definition
Major extracranial and intracranial arteries, as well as the aorta prior to the major vessels
Term
Where do thrombi that form emboli appear in the heart?
Definition
Left atrium, mitral valve, or aortic valve
Term
What are the intracranial hemorrhages usually associated with stroke?
Definition
Suparachnoid, intraventricular, or parenchymatous cerebral hemorrhages
Term
What is the most common form of direct hemorrhage associated with stroke?
Definition
Sub-arachnoid hemorrhge
Term
Why are cerebral hemorrhages characterized as lacunar?
Definition
They multiply in incidence over time
Term
What are major risk factors for cerebral hemorrhage?
Definition
Hypertension, diabetes, and atherosclerotic disease
Term
What defines an aneurysm?
Definition
Dilation of a vessel wall with the cavity remaining continuous with the vessel of origin
Term
Intracranial aneurysms most frequently occur at what points?
Definition
Branch points of vessels
Term
What are some treatments for aneurysms?
Definition
Clipping the aneurysm at the stalk or running a wire coil into the aneurism to induce clotting
Term
What usually causes a congenital aneurysm?
Definition
Weakness of the tunica media near a branch of the circle of Willis
Term
What are some symptoms of aneurysm rupture in the subarachnoid space?
Definition
Severe headache, mental confusion, loss of consciousness
Term
Carotid aneurysms in the cavernous sinus can result in the compression of what cranial nerves?
Definition
III, IV, VI, maxillary branches of V, and opthalmic
Term
Arteriovenous malformations are defined as what?
Definition
Abnormal communication between cerebral arteries and veins resulting in a tortuous mass of interconnecting channels
Term
What arteriovenous malformation is considered a special type seen primarily in newborns or infants?
Definition
Malformations of the great cerebral vein of Galen
Term
Arteriovenous malformations of the great cerebral vein of Galen induce what symptoms?
Definition
Bulging fontanelles, progressive hydrocephalus, dilated veins of the face and scalp
Term
Occlusion of what vessel may cause an infarction of the entire hemisphere with the exception of the thalamus, inferior portion of the temporal lob, and medial portion of the occipital lobe?
Definition
Internal carotid
Term
What defines a transient ischemic attack?
Definition
A small emboli partially occluding a small cerebral vessel, producing sudden neurological deficits that last less than 24 hours, typically less than 10 minutes
Term
How is recovery from a transient ischemic attack characterized?
Definition
Recovery is complete
Term
A transient ischemic attack in the retinal branches of the opthalmic artery produces what?
Definition
Amaurosis fugax - transient blindness on the affected side seen often as a window shade over the eye
Term
How do transient ischemic attacks act as prognostic indicators of stroke?
Definition
1/3 of untreated transient ischemic attack patients suffer from a stroke within 5 years
Term
What are symptoms of transient ischemic attacks in carotid circulation?
Definition
Ipsilateral amaurosis fugax, contralateral sensory or motor dysfunction, language deficits
Term
What are symptoms of transient ischemic attacks in vertebrobasilar circulation?
Definition
Bilateral or shifting motor sensory dysfunction, bilateral visual disturbances, bifacial numbness, vertigo, diplopia, ataxia
Term
Where are the watershed zones?
Definition
Border zones between the area supplied by the anterior, middle, and posterior cerebral arteries
Term
What might cause ischemia in watershed zones?
Definition
Cardiac surgery, severe arterial hypotension, prolonged hypoxemia, and severe carotid artery disease
Term
Where do lacunar infarction occur?
Definition
Ischemic strokes in the deep region of the brain or brainstem (excluding the cerebral cortex)
Term
Lacunar infarctions result form the occlusion of what arteries?
Definition
Anterior choroidal, middle cerebral, posterior cerebral, and basilar arteries, results in little cavities filled with fluid
Term
What are risk factors for lacuna infarctions?
Definition
Chronic hypertension and diabetes mellitus
Term
What are common syndromes of lacunar infarctions?
Definition
Pure motor stroke involving descending motor fibers, ataxic hemiparesis (clumsy hands), pure sensory stroke
Term
The medulla oblongata is derived from what developmental structure?
Definition
Rhombencephalon
Term
The medulla oblongata contains primary nuclei responsible for what functions?
Definition
Autonomic control of respiration, heart rate, and blood pressure
Term
What long tracts are associated with the medulla oblongata? What is the relationship between the medulla oblongata and the long tracts of the nervous system?
Definition
Dorsal column-medial lemniscal system and corticospinal tracts both decussate (cross) from one side to the other at the medulla oblongata
Term
Where does the pyramidal decussation appear on the medulla?
Definition
Ventral surface as a minor disruption of the anterior median fissure
Term
Which long tract has 80-90% of its fibers crossing over at the level of the ventral caudal medulla?
Definition
Corticospinal tract, descends in the lateral funiculus
Term
Where do fibers within the fasciculus gracilis and fasciculus cuneatus begin to synapse?
Definition
Nucleus Gracilis and nucleus cuneatus of the pyramidal decussation respectively
Term
Where is the spinal trigeminal nucleus located?
Definition
Lateral medulla between the caudal pons and the upper cervical spinal cord within the grey matter of the dorsal horn
Term
What takes place in the tract of Lissauer?
Definition
Spinal trigeminal tract
Term
What is the surface marking given off by the spinal trigeminal nucleus?
Definition
Tuberculum cinereum
Term
What are the divisions of the spinal nucleus within the medulla?
Definition
Pars Oralis, Pars Interpolaris, Pars Caudalis
Term
What are the boundaries of the Pars Oralis and what type of sensory input does it receive?
Definition
Rostral pole of hypoglossal n. to caudal end of pons, receives crude touch input
Term
What are the boundaries of the Pars Interpolaris and what type of sensory input does it receive?
Definition
Obex to rostral pole of hypoglossal nucleus, receives input for dental pain
Term
What are the boundaries of the Pars caudalis and what type of sensory input does it receive?
Definition
C3 to the obex, receives input for pain and temperature input
Term
What part of the spinal medula synapses with V1, V2, and V3?
Definition
Pars caudalis
Term
Where is the spinal accessory nucleus located?
Definition
Lateral portion of the ventral horn from C5 or C6 to C1
Term
What type of innervation does the accessory cuneate nucleus receive?
Definition
Proprioceptive information from the upper limb destined for the cerebellum
Term
What is the name of the projections traveling from the accessory cuneate nucleus to the cerebellum?
Definition
Cuneocerebellar tract
Term
What tracts are found in the midline behind the medial lemniscus of the medulla?
Definition
Tectospinal tract and medial longitudinal fasciculus
Term
What are the major vessels that supply blood to the medulla?
Definition
Anterior spinal artery, vertebral arteries, posterior spinal artery
Term
The level of the obex is associated with which cranial nerve?
Definition
CN XII (hypoglossal n.)
Term
What unique structure is found in the upper medulla?
Definition
Area postrema
Term
What is the function of the area postrema?
Definition
Contains sinusoid capillaries with chemosensitive zones that can trigger emesis (vomiting)
Term
What pathway is provided by the restiform body within the inferior cerebellar peduncle?
Definition
Major afferent pathway for the cerebellum, also carries cuneocerebellar tract
Term
Where does the ventral trigeminothalamic tract originate and what type of innervation does it carry?
Definition
Spinal trigeminal nucleus, carries pain and temp signals from the face
Term
What are the prominent features of the midolivary level of the medulla?
Definition
Inferior olivary complex, exit points for the hypoglossal and vagus nerves
Term
What are the components of the inferior olivary complex?
Definition
Principal olivary nucleus, medial accessory, and dorsal accessory olive
Term
What is the function of the principal olivary nucleus
Definition
Involved in control of planned or skilled voluntary movements
Term
What is the function of the medal and dorsal accessory olives?
Definition
Receive spinal afferents for sterotyped movements
Term
How does the inferior olivary complex project to the cerebellum?
Definition
Via olivocerebellar tract within the contralateral inferior cerebellar peduncle
Term
Where is the hypoglossal nucleus located?
Definition
Deep to the hypoglossal trigone present on either side of the median sulcus in the medullarly portion of the rhomboid fossa
Term
Where do hypoglossal motor neurons emerge from the brainstem?
Definition
Between the pyramid and the inferior olive in the preolivary sulcus
Term
What is innervated by the ambiguus nerve?
Definition
Primarily SVE motor innervation to muscles derived from pharyngeal arches, some GVE to cardiac ganglia
Term
The nucleus ambiguus contributes to which cranial nerves?
Definition
IX, X, XI
Term
Where is the dorsal motor nucleus of the vagus located?
Definition
Deep to the vagal trigone and lateral to the hypoglossal trigone in the floor of the 4th ventricle
Term
What are the two zones of the solitary nucleus?
Definition
Rostral gustatory zone and caudal cardiorespiratory zone
Term
What is the function of the rostral gustatory zone of the solitary nucleus?
Definition
Receives taste afferents (SVA) via CN VII, IX, X
Term
Neurons from the gustatory zone of the solitary nucleus project to what structure?
Definition
Thalamus
Term
What is the function of the caudal cardiorespiratory zone of the solitary nucleus?
Definition
Receives GVA input from CN IX and X from the lungs and GI tract as well the carotid sinus and carotid body
Term
What is the function of the vestibular nuclei?
Definition
Receives input form labyrinth of the inner ear involved in equilibrium and control of eye movement
Term
What is the function of the salivatory nucleus?
Definition
Origin of parasympathetic innervation to parotid gland, fibers synapse in otic ganglia
Term
The medulla oblongata is derived from what developmental structure?
Definition
Rhombencephalon
Term
The medulla oblongata contains primary nuclei responsible for what functions?
Definition
Autonomic control of respiration, heart rate, and blood pressure
Term
What are the two major regions of the adult pons?
Definition
Dorsal/medial portion (pontine tegmentum) and ventral/lateral portion (basilar pons)
Term
What is the primary ascending auditory pathway formed by the dorsal and ventral cochlear nuclei?
Definition
Lateral lemniscus
Term
Do axons from the dorsal and ventral cochlear nucleus collect to the ipsilateral or contralateral lateral lemniscus?
Definition
Contralateral lateral lemniscus
Term
How does the vestibular nuclei send projections to the oculomotor nuclei and that thalamus?
Definition
Via medial longitudinal fasciculus
Term
How does the vestibular nuclie send projections to the spinal cord?
Definition
Via lateral vestibulospinal tract (to extensor spinal alpha motorneurons) and medial vestibulospinal tract (contributes to head righting reflexes in relation to vision)
Term
What is the function of the facial motor nucleus?
Definition
Facial motor SVE to pharyngeal arch muscles
Term
Internal facial nerve axons loop around what structure before exiting anterior CN VIII at the pontomedullary junction?
Definition
Nucleus of CN VI
Term
What is the name of the bump visible on the floor of the fourth ventricle?
Definition
Facial colliculus
Term
What is makes up the facial colliculus?
Definition
Abducens nucleus surrounded by axons of CN VII
Term
Are cortical innervation by facial nerve bilateral, contralateral, or ipsilateral?
Definition
Bilateral for muscles of the forehead but contralateral for lower facial muscles
Term
CN VII (facial n.) sends parasympathetic GVE innervation to what structures?
Definition
Lachrymal glands, mucous membranes of the nose and hard/soft palates, and submandibular glands
Term
CN VII (facial n.) sends parasympathetic GVE innervation to salivary glands via what structure?
Definition
Superior salivatory nucleus within the dorsolatoral reticular formation, synapses at the pterygopalatine and submandibular ganglia
Term
How is CN VII (facial nerve) involved in emotional responses?
Definition
Involved in parasympathetic reflex circuits that trigger lachrymation or salivation
Term
What provides innervation for taste for 2/3 of the tongue and palates via geniculate ganglion?
Definition
CN VII (facial n.) via SVA signals
Term
What receives SVA innervation from taste buds?
Definition
Solitary nucleus which relays via central tegmental tract to the thalamus
Term
CN VII (facial n.) provides GSA innervation for what structures?
Definition
Skin of the ear wall and external tympanic membrane via geniculate ganglion
Term
Where does CN VI (abducens n.) exit the midbrain?
Definition
Inferior pontine sulcus
Term
The abducens nerve supplies exclusive motor innervation to what muscle?
Definition
Lateral rectus muscle of the eye on ipsilateral side
Term
Which long tracts run through the substance of the basilar pons?
Definition
Corticospinal and corticonuclear (bulbar) tracts
Term
What is the result of the medial lemniscus turning as it enters the caudal pons?
Definition
Somatotopically shifts so the leg areas are more lateral
Term
What supplies blood to the pontomedullary junction and the caudal pons?
Definition
Vertebral arteries, basilar artery, PICA, and AICA
Term
What supplies blood to the structures in the ventral and medial pontomedullary junction/caudal pons?
Definition
Vertebral arteries and medial branches of the basilar artery
Term
What supplies blood to the structures in the dorsolateral pontomedullary junction/caudal pons?
Definition
PICA
Term
The mandibular branch of CN V (trigeminal n.) sends SVE motor innervation to what structures?
Definition
Muscles of mastication, tensor tympani, tensor palatini, mylohyoid, and anterior belly of digastric
Term
Where is the motor nucleus of CN V (trigeminal n.) located?
Definition
Under the superior cerebellar peduncle medial to the chief sensory nucleus
Term
Is motor innervation by the mandibular branch of CN V (trigeminal n.) bilateral, contralateral, or ipsilateral?
Definition
Crosses bilaterally, initially contralateral deficit eventually recovers
Term
What sensory functions are carried via the trigeminal ganglia?
Definition
Discriminative touch to mobile head structures, protopathic (pressure) touch, pain, temp
Term
How are the V1, V2, V3 dermatomes of the trigeminal n. organized?
Definition
V1 = scalp to below nose, V2 = temple to upper lip, V3 = temple to chin
Term
The spinal nucleus of CN V is primarily concerned with what type of GSA innervation from the face?
Definition
Pain and temp
Term
The spinal nucleus receives sensory information from what cranial nerves?
Definition
CN V, VII, IX, X
Term
What is the equivalent of the dorsal column nuclei for the face (discriminitave touch and pressure)?
Definition
Primary sensory nucleus
Term
What makes up the primary sensory nucleus?
Definition
Pontine trigeminal nucleus, trigeminal principle nucleus, chief sensory nucleus of CN V
Term
What is the function of the mesencephalic nucleus?
Definition
Primarily concerned with stretch and pressure proprioception for muscles involved in mastication and the bite reflex (projects to motor nucleus of CN V)
Term
Which tract formed by the sensory nuclei of CN V crosses?
Definition
Ventral trigeminal tract crosses, dorsal does not
Term
What supplies blood to the upper pons?
Definition
Primarily by branches of the basilar artery, upper levels also supplied by superior cerebellar artery
Term
What is the developmental origin of the midbrain?
Definition
Mesencephalon
Term
What make up the tectum of the midbrain?
Definition
Acts as roof of the midbrain, consists of the superior and inferior colliculi
Term
What makes up the tegmentum of the midbrain?
Definition
Nuclear area and fiber tracts around the ventricle, includes the periaqueductal grey and red nucleus
Term
What make up the basis pedunculi of the midbrain?
Definition
Crus cerebri and the substantia nigra
Term
The large bundle of descending tracts originating from the cerebrum that is found in the midbrain is known as what?
Definition
Crus cerebri
Term
The space between the peduncles on the ventral surface of the midbrain is known as what?
Definition
Interpeduncular fossa
Term
What nerve exits from the interpeduncular fossa?
Definition
CN III (oculomotor n.)
Term
What GSE function does CN III (oculomotor n.) serve?
Definition
Motor to the levator palpebrae muscles and the 4 extraocular muscles - superior, medial, and inferior rectus and the inferior oblique
Term
What GVE function does CN III (oculomotor n.) serve?
Definition
Preganglionic parasympathetic fibers to ciliary ganglion which innervates sphincter pupillae and ciliary muscles
Term
What does CN III (oculomotor n.) arise from?
Definition
Oculomotor nucleus
Term
Where is the Edinger-Westphal nucleus located?
Definition
ANterior median part of the oculomotor complex
Term
What is the function of the Edinger-Wesphal nucleus?
Definition
Axons run alongside CN III from the ciliary ganglion, is affected by pressure and causes pupil dilation if conduction is blocked
Term
Where is the CN IV (trochlear n.) nucleus located?
Definition
Midbrain at the level of the inferior colliculus
Term
What is unique about how CN IV (trochlear n.) exits from the brainstem?
Definition
Only cranial nerve to exit dorsally from the brainstem
Term
CN IV (trochlear n.) supplies GSE motor innervation to what structures?
Definition
Superior oblique muscle which intorts and depresses the eye. Lesions result in difficulty going down stairs
Term
What is the function of the superior colliculus?
Definition
Coordinates reflexes to visual stimuli via conjugate eye movements, reflex closure of the eye, and accommodation focusing of lens for near vision
Term
What efferent tracts are found int he superior colliculus?
Definition
Tectobulbar and tectospinal tracts
Term
What is the function of the tectobulbar tract?
Definition
Controls eye movements, reflex closure
Term
What is the function of the tectospinal tract?
Definition
Crossed to upper spinal cord for neck muscle used in tracking objects in the visual field
Term
What is the function of the inferior colliculus?
Definition
Acts as a nuclear relay station of the auditory pathway and coordinates reflexes to auditory stimuli with the help of the superior colliculus and the tectobulbospinal tract
Term
What is the main afferent input of the inferior colliculus?
Definition
Lateral lemniscus which is the fiber tract primarily originating in the cochlear nuclei
Term
What is the main efferent output of the inferior colliculus?
Definition
To inferior brachium which connects it to the medial geniculate nucleus of the thalamus
Term
What are the main afferents of the red nucleus?
Definition
From cerebellar nuclei via the superior cerebellar peduncle as well as corticorubral fibers for motor function
Term
What are the main efferents of the red nucleus?
Definition
Rubrospinal tract - crossed spinal projection that is flexor biased to upper limb
Term
What are the two divisions of the substantia nigra?
Definition
Pars compacta and pars reticulata
Term
What neurotransmitter is found in the pars compacta?
Definition
Contains dark pigments of neuromelanin that is a complex of the neurotransmitter dopamine
Term
Spontaneous degeneration of pars compacta neurons is associated with what disease?
Definition
Idiopathic Parkinson's disease
Term
What neurotransmitter is found in the pars reticulata?
Definition
GABAergic neurons that project to the thalamus and serve as an output nucleus of the basal ganglia system
Term
What are the major connections of the substantia nigra?
Definition
Reciprocal contacts with subcortical motor nuclei such as the corpus striatum and subthalamic nucleus which are associated with basal ganglia
Term
What type or neurotransmitter receptor neurons are found in the ventral tegmental area?
Definition
Dopaminergic neurons
Term
The ventral tegmental area of the midbrain projects to what areas?
Definition
Areas associated with the limbic system such as the hippocampus, hypothalamus, and ventral striatum. Associated with the central reward pathways and possible mental disorders
Term
What are the major divisions of the crus cerebri from medial to lateral within the midbrain?
Definition
Fronotpontine, corticobulbar, corticospinal, and parietotemporopontine tracts
Term
Where do the descending fiber tracts of the crus cerebri originate?
Definition
Cerebral cortex
Term
Where is the nuclei of the pretectum located?
Definition
Found rostral to the superior colliculus at the level of the posterior commissure
Term
What is located at the pretectum nuclei?
Definition
Contains five nuclei related to visual function - Nucleus of the optic tract, sublentiform nucleus, nucleus of the pretectal area, pretectal olivary nucleus, principal pretectal nucleus
Term
What is the function of the prectum nuclei?
Definition
Receives fibers from the optic tract, lateral geniculate nucleus, cortex, and posterior thalamic nuclei and mediates the pupillary light reflex. Large lesions are required to impair this reflex
Term
What mediates the vertical conjugate gaze mechanism?
Definition
Vertical gaze center in the midbrain-diencephalon junction
Term
What is the primary nucleus of vertical gaze center?
Definition
Rostral interstitial nucleus of the medial longitudinal fasciculus
Term
What nuclei aids the vertical gaze center to hold eye position in vertical gaze as well as in coordination of rotary eye movements?
Definition
Interstitial nucleus of cajal
Term
How does the interstitial nucleus of cajal and the rostral interstitial nucleus of the medial longitudinal fasciculus communicate?
Definition
Via posterior commissure
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