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
|
|
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
|
|
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
|
|
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
|
|
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
|
|
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
|
|
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
|
|
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
|
Definition
| Lack of movement or an inability to initiate movement (can be due to basal ganglia damage) |
|
|
Term
|
Definition
| Abnormally slowing of movement (can be due to basal ganglia damage) |
|
|
Term
|
Definition
| Decrease of handwriting size, an early expression of bradykinesia (can be due to basal ganglia damage) |
|
|
Term
|
Definition
| Increased continuous resistance to passive movement (can be due to basal ganglia damage) |
|
|
Term
|
Definition
| Involuntary continuous body movement (can be due to basal ganglia damage) |
|
|
Term
|
Definition
| Slow, purposeless movement such as lip smacking (sign of basal ganglia damage) |
|
|
Term
|
Definition
| Persistent form of one movement of athetosis resulting in sustained muscle contraction producing postural abnormality (sign of basal ganglia damage) |
|
|
Term
|
Definition
| Violent flinging of the limb or limbs (sign of basal ganglia damage) |
|
|
Term
|
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
|
|
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
|
|
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
|
|
Term
| Striatal medium spiny projections of neurons of indirect pathways in the basal ganglia couple GABA withw hat? |
|
Definition
|
|
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
|
|
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
|
|
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
|
|
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
|
|
Term
| Are cerebellar lesions expressed contralaterally, ipsilaterally, or bilaterally? |
|
Definition
|
|
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
|
|
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
|
|
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
|
|
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
|
|
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
|
|
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
|
|
Term
| The white matter covering the dorsal thalamus is known as what? |
|
Definition
|
|
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
|
|
Term
| The lateral groups in the thalamus is further divided into what? |
|
Definition
|
|
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
|
|
Term
| Zona incerta of the subthalamus is an extension of what structure? |
|
Definition
|
|
Term
| The subthalamus contains basal ganglia projections in what? |
|
Definition
|
|
Term
| What is the pineal gland associated with? |
|
Definition
|
|
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
|
|
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
|
Definition
| Spontaneous contraction of individual muscle fibers within motor units after denervation? |
|
|
Term
|
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
|
|
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
|
|
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
|
|
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
|
|
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
|
|
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
|
|
Term
| NREM and NREM sleep cycles occur in what time intervals? |
|
Definition
|
|
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
|
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
|
|
Term
| Sleep terrors are most commonly associated with children and usually begin in what stages of NREM sleep? |
|
Definition
|
|
Term
| Brain metabolism is based almost entirely on the oxidation of what? |
|
Definition
|
|
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
|
|
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
|
|
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
|
|
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
|
Definition
| Increased CO2 -> vessels dilate |
|
|
Term
|
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
|
|
Term
| What is the most abundant perivascular neurotransmitter? |
|
Definition
|
|
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
|
|
Term
| How long does it take for interruption of cerebral blood flow to inhibit synaptic excitability of cortical neurons? |
|
Definition
|
|
Term
| How long does it take for interruption of cerebral blood flow to inhibit electrical excitability altogether? |
|
Definition
|
|
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
|
|
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
|
|
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
|
|
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
|
|
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
|
|
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
|
|
Term
| What is the surface marking given off by the spinal trigeminal nucleus? |
|
Definition
|
|
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
|
|
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
|
|
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
|
|
Term
| What unique structure is found in the upper medulla? |
|
Definition
|
|
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
|
|
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
|
|
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
|
|
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
|
|
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
|
|
Term
| What is the name of the bump visible on the floor of the fourth ventricle? |
|
Definition
|
|
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
|
|
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
|
|
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
|
|
Term
| The spinal nucleus receives sensory information from what cranial nerves? |
|
Definition
|
|
Term
| What is the equivalent of the dorsal column nuclei for the face (discriminitave touch and pressure)? |
|
Definition
|
|
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
|
|
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
|
|
Term
| The space between the peduncles on the ventral surface of the midbrain is known as what? |
|
Definition
|
|
Term
| What nerve exits from the interpeduncular fossa? |
|
Definition
|
|
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
|
|
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
|
|
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
|
|
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
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