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454 Cards in this Set
- Front
- Back
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Hypothalamus
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a
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What is the anterior boundary of the hypothalamus?
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Lamina terminalis
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What is the posterior boundary of the hypothalamus?
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posterior perforated substance
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What is the superior boundary of the hypothalamus?
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Hypothalamic sulcus
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What are the structures which form the floor of the hypothalamus?
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optic chiasm, tuber cinareum, infundubulum, mamillary body, post perforated substance
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What is the name of the most anterior region of the hypothalamus and what are its nuclei?
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preoptic region: medial and lateral preoptic nucleu
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What is the specialty of medial Preoptic nuclei?
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sexually dimorphic (homosexuallity)
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What is the importance of lateral Preoptic nuclei?
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sleep
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What are the hormones released by the nuclei of Supraoptic region?
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oxytocin and ADH
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Supraoptic and Paraventricular nuclei terminate where?
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median eminence
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Where the hypothalamo-hypophyseal Portal system does begin?
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median eminence
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Where the hypothalamo-hypophyseal portal system terminates?
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base of anterior pituitary
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Where the releasing hormones enter the portal system?
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median eminence
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What is the function of ventromedial nucleus and what happens if there is a lesion to it?
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saity center, lesion = hyperphasia
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What is the function of the lateral nucleus and what happens if there is a lesion to it?
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feeding center, lesion = hyperphasia
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What happens if there is bilateral lesion to Supraoptic region?
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no ADH or oxytocin
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What is the only area which releases the histamine in the brain?
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tubermamillary nucleus
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What happens when there is a lesion of the ventromedial nucleus?
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hypothalamic hyperphasia
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Orexin is released from which nucleus of the hypothalamus?
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TMN or lateral and post sections
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Where is Ob receptors situated? What is the effect of leptin on hypothalamic hormones?
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ventromedial nucleus, reduces appetite and increases ACTH and FSH
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What happens when the posterior part of the hypothalamus is cut? And when it is used clinically?
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poikoliothermia, contorl agressiveness and BP
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What is circadian rhythm and which nucleus is responsible for this?
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suprachiasmatic nucleus, slee/wake cycle
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Which tract connects the retina with the hypothalamus?
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retinohypothalamic (suprachiasmatic nuclei)
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What receptors are present in the suprachiasmatic nucleus?
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melatonin R's
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What is poikilothermic and which part of thalamus is involved in this?
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post part, body temp varies with environment
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Which neurotransmitter prevents the release of prolactin and where is it released?
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dopamine, arcuate nucleus
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What is the agonist of dopamine that is used in Prolactinoma?
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bromocriptine
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In which syndrome the Mamillary body is involved?
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poikilothermia
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Which part of the hypothalamus is surgically cut in controlling violent behavior of psychiatric patient?
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posteromedial
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What is the biochemical effect of paucity of leptin?
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stim neuropepide Y, incs appetite and decs ACTH and FSH
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What is the biochemical effect of increased level of leptin?
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decd hunger and incd ACTH and FSH
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Which drug is used in narcolepsy?
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orexin/hypocretin
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What is the effect of Orexin on histamine release?
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stimulates it
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Where is anti rise center of temperature in the hypothalamus?
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anterior hypothalmus
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Where is anti drop center of temperature in the hypothalamus?
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mamillary nucleus, post hypothalmus
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Which nucleus acts like switch of non-REM sleep? And what it its neurotransmitter?
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lateral preoptic; GABA
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Name the structure which separates the medial and lateral hypothalamus?
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fornix
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· Name the bundle which traverses the lateral hypothalamus?
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medial forebrain bundle
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What are the other parts of cerebellum included under the vestibular cerebellum (balance)?
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vermis and flocculonodular
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What is the nucleus of the vestibular cerebellum?
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fastigal nucleus
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Name four tracts that are modulated by the vestibular cerebellum?
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anterior corticoS, tectoSpinal, reticulospinal, vestibulospinal
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What is uncinate fasciculus and through which peduncle it passes and what are the two tracts controlled by this fasciculus?
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medial motor tracts' controlling axial musculature, pass through SCP; controls tectospinal and anterior corticospinal
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What are the two major nuclei of medulla connected to the vestibular cerebellum through the inferior cerebellar peduncle?
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vestibular nucleus in medulla, and fastigal nucleus
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What are the two tracts controlled by the vestibular cerebellum through the inferior cerebellar peduncle?
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vestibulospinal and reticulospinal
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What is the name of the nucleus of the spinal cerebellum (paravermal)?
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interpositus
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What are the two components of the nucleus interpositus?
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emboliform and globbus
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What are the two tracts that are modulated by the spinal cerebellum and through which peduncle these tracts are controlled?
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lateralcorticospinal and rubrospinal
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What are the two tracts that reach the spinal cerebellum and through which peduncle they pass?
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same as Q b4/ SCP
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What is the name of the afferent tract that reaches the lateral cerebellum from the cerebrum?
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central segmental tract
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Where does the corticoponticerebellar tract crosses?
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Through which peduncle the corticoponticerebellar tract passes?
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MCP
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Which area is controlled by the lateral cerebellum?
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prefrontal cortex
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What is the nucleus of lateral cerebellum?
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dentate
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What is the pathway of learning?
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papez
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If left cerebellum has a lesion, to which side patient falls?
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left
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If right vestibular nucleus has a lesion, to which side patient falls?
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right
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What are the two tracts controlled by the vermal (vestibular) cerebellum through inferior cerebellar peduncle?
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vestibulo and reticulospinal
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What are the two tracts modulated by the paravermal (spinal) cerebellum?
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lateral cortico and rubro
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Whether weakness is a sign of cerebellar disease? If not what is the sign of cerebellar disease?
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ataxia, muscle tone, balance
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Trace the pathway from a vestibular nucleus to the horizontal conjugate deviation?
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R vestibular nn> L PPRF > L cn 6 nn > L lateral rectus
L Cn6 nn > R MLF > R CN 3 nn > R medial rectus |
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Left vestibular nucleus is connected with which nucleus?
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R PPRF
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In which direction you see the slow horizontal conjugate deviation when cold water is inserted into the right ear?
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right
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In which direction you see the fast horizontal conjugate deviation when cold water is inserted into the right ear?
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left
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In which direction the fast and slow horizontal movements of eyes are seen when the cold water is inserted into the left ear?
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L - slow, R - fast
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In which direction the fast and slow horizontal movements of eyes are seen when the warm water is inserted into the left ear?
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Left fast, right slow
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Which movement of the caloric test is lost when there is a lesion superior to the level of midbrain?
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no fast compontent (opp)
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What is the response of the left eye in caloric testing when left medial longitudinal fasciculus (MLF) has a lesion?
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no response during conjugate deviation of the eye
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What is the response of both eyes in caloric testing when MLF has lesion bilaterally?
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cold Left cant adduct, warm right cant adduct
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What response you see for caloric testing when there is a low brainstem lesion?
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no response
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What is Doll’s maneuver?
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eyes deviate to opp side direction of head tilt
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What are the excitatory tracts in the cerebellum?
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ventral spinocerebellar, corticopontocerebellar, dorsal spinocerebellar, vestibulospinal tract
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Which part of the cerebellum is affected in alcoholic cerebellar disease and what are the signs?
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anterior lobe of the vermis
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What is the ascending tract that traverses the superior cerebellar peduncle?
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ventral spinocerbellar
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What is the ascending tract that traverses the middle cerebellar peduncle?
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corticopontocerebellar
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Where do climbing fibers begin and where do they terminate?
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inferior olivary nucleus, olivocerebellar
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What are the tracts which are grouped under mossy fibers?
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all of the excitatory tracts: ventral spinocerebellar, corticopontocerebellar, dorsal spinocerebellar, vestibulospinal t
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Where do mossy fibers terminate?
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cerebellar granule layer
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Lecture objectives and practice questions: Basal ganglia
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· What is corpus striatum?
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neostratium + paleostratium AKA: caudate n + lentiform n
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· What is nucleus accumbens or ventral striatum?
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reward and addiction center
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· Which part of the internal capsule lies between the caudate nucleus and putamen?
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ant limb
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· Name all the structures that you encounter from the lateral sulcus to the third ventricle?
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lateral suclus > insula > putanem >LML> GPE >MML> GPi > post limb of IC > thalmus > 3rd ventricle.
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What are the nuclei that are included under basal ganglia?
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caudate NN and Putanem, GPE, GPi, subthalamic thalmus (ventral anterior)
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What are the two nuclei included under the lentiform nucleus?
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retrolentiform and sublentiform
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What are the two nuclei that form the neostriatum?
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caudate and putanem
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Which one is paleostriatum?
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(Globus pallidus belongs to paleostriatum means old in evolution)
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What is the name of the fibers that connect the cerebral cortex with the neostriatum? What transmitter is released at their endings?
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corticostriate; glutamate
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What is the name of the fibers that connect the striatum with the globus pallidus internum and what transmitter is released at their endings?
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striatal neurons. substance P and Gaba
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The fibers of the globus pallidus internum are projected to which nucleus of thalamus? What is the neurotransmitter at their nerve endings in thalamus?
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ventral anterior. gaba
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What is the name of the tract that connects the thalamus to the cortex and what neurotransmitter is released?
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thalamocortical? glutamate
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Trace the direct pathway from cortex back to cortex?
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Glu > gaba > gaba >glu
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Trace the indirect pathway from cortex back to cortex?
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GLU > gaba > gaba > glu > Gaba > glu
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Name the neurotransmitters released in the globus pallidus externum?
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GABA and encephelin
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What is the name of the fibers that connect the globus pallidus externum to subthalamic nucleus?
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GABA
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What is the name of the fibers that connect the subthalamic nucleus with the globus pallidus internum? What neurotransmitter is released?
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GLU; subthalamopallidal fibers
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What type of dopamine receptors is present in the striatal neurons of the direct pathway?
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D1, D5
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What type of dopamine receptors is present in the striatal neurons of the indirect pathway?
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D2
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Where is dopamine producing neurons present and what is the effect of dopamine on the direct pathway?
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SN pars compacta
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What is the effect of dopamine on the indirect pathway?
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inhibit inhibition
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What is the final effect of direct pathway on the cerebral cortex?
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excitation
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What is the final effect of indirect pathway on the cerebral cortex?
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inhibition
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Which neurotransmitter is compromised in hypokinetic disorder of basal ganglia?
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dopamine
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Which neurons are involved in the hyperkinetic disorder of the basal ganglia and what neurotransmitter it releases?
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encephalin containing striatal neurons of the indirect pathway are most affected. this removes the inhibition on GPe, which goes to inhibit the subthalamic nucleus (via GABA) and ultimatly results in a hyperkinetic disorder.
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Which neurotransmitter is compromised in hypokinetic disorder of basal ganglia?
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loss of dopamine results in a net inhitbtion of the thalmus (not excitation via direct path)
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Why do you see hydrocephalus ex vacuo in Huntington’s chorea?
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degeneration of caudate and brain matter
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What are signs of Huntington’s chorea? What is responsible for Huntington’s disease?
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What are the three signs of Parkinsonism?
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resting tremor, bradykinesia, hypokinesia, lead pipe and cogwheel rigidity
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What are the various treatment options of parkinsonism?
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levedopa, carbidopa. anticholinergics, MAOIb (seleginline)
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Why do you use Anticholinergic drugs to treat Parkinsonism?
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removal of cholinergic stimulation of indirect pathway results in decreased inhibiont
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What is Hemiballismus and how is it caused?
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upperbody fliging, contralateral subthalamic nucle
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Name the fascicule which hooks round the internal capsule and connects the globus pallidus internum with the thalamus?
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ansa leticularis
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Name the fasciculus that passes through the internal capsule and connects the globus pallidus internum with the thalamus?
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Lenticular fasciculus
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Name the fasciculus that connects the globus pallidus with the subthalamic nucleus?
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subthalamic fasciculus
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What is the treatment option of blepharospasm?
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Botulinum toxin
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How sydenham’s chorea is caused and what is treatment for that?
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Nontreatment of streptococcal infections, antibiotics; antibodies target....
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What is Wilson’s disease and give three characteristic features of Wilson’s disease?
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Autosomal recessive disorder of copper excretion. Dystonia rigidity, tremor, choreoathetosis, psychiatric disturbance
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Why patients with Parkinson disease have flat effect and reduced spontaneity?
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Reduced activity of dopamine reduces the activity of the mesocortical pathway (projects to the frontal lobe?) resulting in this affect and reduced spontaneity
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Tourette’s syndrome
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?
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Objectives and practice questions -5
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List all the signs of cerebellar disease?
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• There is no muscle paralysis but there is hypotonia (hypotonia – loss of resistance to passive manipulation. Results in a floppy and loose-jointed muscles)
• Patient falls to the side of the lesion (disequilibrium – loss of balance) • Pendular reflexes are seen • There is intention tremor • Fingernose test is positive • Dysdiadochokinesia( rapid pronation and supination is not possible) • Ataxia ( walking like a drunken man) • Scanning speech |
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What is dysmetria and how do you test it with a patient?
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a form of ataxia (disturbance in performance of smooth voluntary motor acts). Patient cant control range of motion test:Move hand and have patient touch finger to it
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What is dysdiadochokinesia?
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another form of ataxia. inability to peform rapidly alteranating movements
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Why toddler cannot balance?
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If left cerebellum has a lesion, to which side patient falls?
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left
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If right vestibular nucleus has a lesion, to which side patient falls?
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right
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Where do climbing fibers begin and where do they terminate?
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Inferior olivary nucleus in medulla terminate in cortex
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What are the tracts which are grouped under mossy fibers?
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DSCT, CCT, VCT, PCT
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Where do mossy fibers terminate?
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granular layer
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What are the cell bodies present in the molecular layer of the cerebellar cortex?
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stellate and basket
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Name the different processes of neurons present in the molecular layer of the cerebellar cortex
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Dendrites of purkinje cells and axons of granular cells (parallel fibers)
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Name the cell bodies present in the granular layer of the cerebellar cortex
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granule and golgi
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What is a glomerulus, where is it present? Name all its constituents?
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A cluster of dendritic ramifications and axon terminals in the granule cell layer Name all its constituents? Excitatory inputs from mossy fibers, inhibitory inputs from golgi cell axon terminals, granule cell dendrites
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List all excitatory elements in the cerebellum
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climbing, mossy, and parallel fibers
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List all inhibitory elements in the cerebellum
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stellate, basket, golgi and purkinje cells
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What are the excitatory neurons in the cerebellum?
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The deep cerebellar nuclei, climbing mossy and parallel fibers
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What are the inhibitory neurons in the cerebellum?
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Descending fibers such as the four listed previously
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What are the excitatory tracts in the cerebellum?
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Corticoponticerebellar, dorsal spinal cerebellar, ventral spinocerebellar, vestibulospinal
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Which part of the cerebellum is affected in alcoholic cerebellar disease and what are the signs?
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Anterior lobe which affects leg and lower trunk function, speech. Leg/speech dystaxia, loss of balance
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What is the ascending tract that traverses the superior cerebellar peduncle?
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Ventral spinal cerebellar
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What is the ascending tract that traverses the middle cerebellar peduncle?
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corticoponticerebellar
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Name three ascending tracts that traverse the inferior cerebellar peduncle?
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Dorsalspinalcerebellar, vestibulocerebellar, reticulospinal
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Alcoholic cerebellar disease:
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It involves the anterior lobe of the cerebellum. Leg region and lower part of the trunk is represented in the anterior lobe. Therefore in this disease, leg dystaxia, loss of balance of lower part of the body is seen. Since the anterior part also controls the speech, there is scanning speech
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Medulloblastoma: .
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This is the brain tumor of the children. It involves the posterior vermis of the cerebellum. This involves trunk mainly. It results in trunk dystaxia. The patient is unable to balance. However while sleeping the patient is able to move the limbs normally. This is because the trunk is supported by the bed.
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What are the signs important for the physical diagnosis of cerebellar disease?
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heal shin +ve, intention tremor, dysdiadochokinesia, heel to walking -ve
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What type of pupil you expect in a patient with diencephalic lesion?
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Small pupils but still reactive because reflexes are intact
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What type of pupil you expect in a comatose patient with Pretectal lesion?
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upward gaze
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What type of pupil you expect in a comatose patient with the lesion of tegmentum of midbrain?
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pupils are fixed midposition
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What type of pupil you see when left oculomotor nerve has lesion?
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Left pupil is dilated and fixed
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What type of pupil you expect in a pontine lesion?
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Pinpoint pupils because only sympathetic fibers are gone
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What is decorticate posturing and what are the two tracts that have escaped to bring about this posture?
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It is where there is injury above level of red nucleus and patient has lower limbs extended with flexion of upper limbs, Rubrospinal and
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What is decerebrate posturing and which tract is cut and which tract is functioning?
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It is injury below level of red nucleus in MB, person has extension of both upper and lower limbs due to lesioned rubrospinal and unopposed vestibulospinal extension
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Should there be a lesion of left MLF which eye shows nystagmus?
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right nystagmus
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If you insert cold water into the ear of a comatose patient with brainstem damage, what is the position of eyes?
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straight forward
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Should you insert cold water into the ear of a patient who is unconscious because of cortical involvement, which phase of VOR is lost?
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?
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What are the symptoms of pseudobulbar palsy?
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Abnormal laughing and crying because of loss of control of limbic system
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Name four clinical conditions associated with midbrain?
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Weber’s, benedicts, perinaud’s
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Name three ’P’s associated with pontine lesion?
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Pinpoint pupils, paralysis, pyrexia
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Name four clinical conditions associated with the lesion of medulla oblongata?
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?
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What are the parts of diencephalon?
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Thalmus and hypothalmus
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Name the cavity of diencephalon
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3rd ventricle
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What is hypothalamic sulcus? Where does it begin and where does it terminate?
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divides diencephalon into dorsal (thalmus) and ventral (hypothalmus), interventricular foramen to cerebral aquadcut
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What are the structures included under metathalamus?
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MGB (hearn), LJB (vision)
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What is epithalamus?
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dorsal divisio: pineal gland, hebenula, post commisure
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What are the medial relations of thalamus?
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epyndyma of 3rd ventricle
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Which structure lies lateral to thalamus?
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post limb of IC, then lentiform
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Which ventricle lies superior to the thalamus?
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lateral ventricle
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Between what structures you find the choroid fissure?
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btw the superior surface of thalmus and fornix
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What lies anterior to the thalamus?
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interventricular foramen
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What happens if there is a tumor at the anterior end of thalamus?
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non-communicating hydrocephalus
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What is the name of the posterior expanded part of thalamus?
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pulvinar
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What is the shape of internal medullary lamina?
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Y shaped
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What are the three basic groups of nuclei of thalamus divided by the internal medullary lamina?
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anterior, medial, and lateral
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Where is reticular nucleus situated?
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btw eml and post limb of IC (lateral surface of thalmus)
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Which structure lies ventral to the thalamus?
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IV foramen
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What are the nuclei of lateral region of thalamus?
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VA (motor), ventral intermediate(motor), VPL(sensory), VPM(sensory), LD(frontal assoc), LP (parietal assoc)
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What is Papez circuit and give its connections?
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A memory circuit: hippocampus-fornix-mamillary body-anterior nucleus of thalamus- cingulated gyrus
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What is Wernicke Korsakoff’s syndrome?
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?
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What is the commencement and termination of fornix?
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?
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VA nucleus of thalamus is connected to what?
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motor
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VL nucleus of thalamus is connected to what?
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motor
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VPL nucleus receives which tracts and where does it project?
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spinalthalamic, projects to sensory cortex for lower body
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VPM nucleus receives sensations from which part of the body?
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head
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Name all the nuclei of ventral tier of lateral group nuclei of thalamus?
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Va, VI, VPM, VPL
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The pain associated with emotion is mediated through the nuclei present within what?
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dorsal medial nuclei
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Which nucleus is important for the localization of the pain?
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VPL
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What are tonic types of cells in thalamus?
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prjoection neurons
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What transmitter is released by the reticular cells?
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GABA, Ca
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Where are reticular cells located?
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thalmus
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Which neurotransmitter is released from the reticular cells?
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GABA
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What is burst potential?
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hyperpolarized beyond tonic range, then depolarized (slightly) with T-type opening
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What types of channels are responsible for the burst potential?
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T-type
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Which channels are implicated in the absence seizures?
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t-type ca channels
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Involvement of what is responsible for the hemianesthesia of the opposite side in the thalamic syndrome?
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VPL? Due to thalamogeniculate branch infarct
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Why severe thalamic pain results in thalamic infarction?
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undue rxs of neurons
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Why thalamic syndrome is associated with contralateral hemiparesis?
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Internal capsule involvement
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Why there is sensory ataxia in thalamic syndrome?
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VPL; loss of 3 sensations and pain and temp
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What is the very important sign of paramedian thalamic infarction?
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hemisensory oss
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Lecture objectives and questions
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Limbic system and Epilepsy
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What are the four functions of limbic lobe
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Homeostasis, olfaction, memory, emotions and drive
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List all structures that are included under limbic lobe
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Hypothalamus, olfactory cortex, hippocampal formation, amygdala
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What are the three parts of hippocampal formation
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Dentate gyrus, hippocampus, subiculum,
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What type of cells is seen in dentate gyrus?
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Granule cells
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What type of neurons is seen in hippocampus?
|
Pyramidal cells
|
|
|
What is the origin and termination of fornix?
|
Medial edge of hippocampus
|
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|
What are the two structures separated by the hippocampal sulcus?
|
Subiculum, denate gyrus
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|
|
Trace the perforant pathway
|
subiculum-across hippocampal sulcus-dentate gyrus granular layer
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What type of fibers arises from the dentate gyrus and where do they terminate?
|
The granule cells give rise to mossy fibers which synapse on dendrites of CA3 pyramidal cells
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What are Schaeffer’s collaterals? What is their origin and termination?
|
? Part of memory formation and emotional network of papez circuit What is their origin and termination? CA3-CA1
• Where do you see the long term potentiation? At CA1 |
|
|
Where do you see the long term potentiation?
|
At CA1
|
|
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What happens to the synapses in long term potentiation?
|
Structural changes in post synaptic membrane
|
|
|
What are the synapses that are remodeled in memory?
|
Glutamate receptors in post synaptic membrane
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Sclerosis of hippocampus results in what/
|
seizure
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What is the relation of hippocampus to the inferior horn of the lateral ventricle?
|
Just below it
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Where amygdaloid body is situated and what is its function?
|
Fear, anxiety, aggression, emotional memories, anteromedial part of temporal lobe in roof of inferior horn of lateral ventricle at anterior end of caudate nucleus
|
|
|
What is the name of the structure that carries fibers from amygdaloid body?
|
Ventral amygdalofugal fibers
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|
What is Sommer’s sector? ( Other name of CA1 is Sommer’s sector)
|
area of hippocampus lying close to subiculum containing pyramidal cells and glutamate receptors
|
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|
Which part of the hippocampus is sensitive to anoxia?
|
CA1
|
|
|
Where do seizures begin in temporal lobe?
|
hippocampus
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|
What is Kluver Bucy syndrome?
|
Lesion to both amygdales- person is tame/nonaggressive/hypersexual/hyperoral
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Name all the structures belonging to the limbic lobe that surround the corpus callosum?
|
?
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Which organism has special affinity to the limbic lobe?
|
herpes
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What is Entorhinal cortex?
|
Anterior part of parahippocampal gyrus- smell
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Trace the perforant pathway from the Entorhinal cortex back to Entorhinal cortex?
|
Entorhinal cortex-perforant pathway-dentate gyrus- mossy fibers-CA3-schaffer collaterals-CA1 pyramidal cells-fornix and subiculum-subiculum-fornix and entorhinal cortex
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|
Where does mossy fibers of cells of dentate gyrus end?
|
CA3
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What is the name of the fibers which extend from CA3 to CA1?
|
Schaffer collaterals
|
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Where do you see LTP taking place?
|
CA1
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In LTP which receptors are increased?
|
glutamante
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In LTP the entry of which ions are critical?(Calcium that enters through glutamate channels is critical for LTP)
|
Calcium that enters through glutamate channels is critical for LTP)
|
|
|
Trace the ‘papez circuit’?
|
(It extends from the hippocampus to Mamillary body to anterior nucleus of thalamus to cingulate gyrus back to Parahippocampal gyrus).
|
|
|
Which part of the brain is implicated in obsessive compulsive disorder?
|
caudate
|
|
|
What clinical syndrome results when there is a bilateral lesion to the amygdala and what are its symptoms?
|
Kluver busy
|
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|
What happens in the top of the basilar artery syndrome?
|
memory loss
|
|
|
What happens when there is aneurysm of anterior communicating artery?
|
memory loss
|
|
|
What is Todd’s paralysis?
|
Seizure in temporal lobe, preictal smell of burning rubber, postictal paralysis due to GABA overactivity
|
|
|
Which channels are implicated in absence seizures?
|
transient T type
|
|
|
What are the treatment options of absence seizures?
|
ca channel blockers
|
|
|
What are the treatment options of seizures?
|
Benzodiazepines- carbamazepine, phentoyin
|
|
|
Which channels are active in the tonic phase of the seizure?
|
glutamate
|
|
|
Which channels get increasingly active during the clonic phase of the seizure?
|
gaba
|
|
|
Should there be a meningioma in the superior longitudinal fissure, what symptoms you expect in the patient?
|
Abulia, apathy, motor inertia, muteness, bilateral involvement of legs
|
|
|
What are the signs and symptoms of a patient who has cavernous thrombosis?
|
Prooptosis and pain in eye, orbit and head on one side, CN3 involvement, dilated pupil unreactant to light, ptosis. Can be in diabetic patients with URI and fungal sinusitis
|
|
|
Lecture objectives and practice questions:
|
|
|
|
Salient points to know in sleep.
|
|
|
|
· Awake brain is desynchronous
|
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|
· Desynchronus means low amplitude and high frequency waves
|
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· Desynchronous results when reticular cells do not release GABA
|
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· Reticular cells also contain transient calcium channels and they do release GABA when they are in the hyperpolarized state at a particular voltage.
|
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· During sleep brain is synchronus
|
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|
|
· Synchronus brain has high amplitude and low frequency waves
|
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|
|
· When reticular cells are in hyperpolarized state at a particular voltage, their voltage gated transient calcium channels open and they release GABA
|
This GABA will bring thalamic cells to the hyperpolarized state where at a particular voltage transient calcium channels open and the thalamus and cortex are synchronized. This synchronization is due to the burst potentials generated. This results in high amplitude and low frequency waves. This synchronized state is sleep.
|
|
|
· Pineal gland
|
eleases melatonin when it is dark and induces drowsiness that precedes sleep. Melatonin is also implicated in jet lag. For jet lag, bright light therapy is employed. In pineal tumor you may expect insomnia.
|
|
|
Restless leg syndrome
|
There is uncomfortable feeling in the legs. Some people may develop deep painful feeling in the legs. Uncomfortable feeling makes patient to move legs. Sometimes are seen when one is resting. Imbalance of brain neurotransmitters especially dopamine is supposed to be the cause. Lack of iron may be one of the reasons. Dopamine agonists may be helpful.
|
|
|
Periodic limb movement disorder;
|
In this disorder movements occur during sleep. It may result in poor sleep and excessive day time sleepiness. It is often associated with restless leg syndrome. Dopamine agonists may be helpful.
|
|
|
What is the amplitude and frequency of the EEG when one is awake?
|
dysnchronous. low amlitude high frequency
|
|
|
What is the amplitude and frequency of the EEG when one is asleep?
|
• During sleep brain is synchronus
• Synchronus brain has high amplitude and low frequency waves |
|
|
What is the neurotransmitter released by the reticular cells?
|
• When reticular cells are in hyperpolarized state at a particular voltage, their voltage gated transient calcium channels open and they release GABA
|
|
|
Should a person is awake but relaxed, what type of waves you see in EEG?
|
alpha: low amplitude high frequency
|
|
|
Should a person is awake but mentally active, what type of EEG you see?
|
beta: low amplitude, extremely high frequency
|
|
|
What is the characteristic appearance of EEG during stage I of sleep?
|
theta
|
|
|
What is the characteristic appearance of EEG during stage II of sleep?
|
theta, sleep spindles, k complex?
|
|
|
What type of waves you see in stage III and stage IV of sleep?
|
delta
|
|
|
What is the amplitude and frequency of the EEG when one is awake?
|
desynchronous. low amp, high freq
|
|
|
What is the amplitude and frequency of the EEG when one is asleep?
|
|
|
|
Where is histaminergic neurons located?
|
TBN
|
|
|
Why antihistamines cause drowsiness?
|
? Because histamines keep the reticular formation and activated and the person awake
|
|
|
Which nucleus inhibits the histaminergic neurons?
|
Ventrolateral preoptic
|
|
|
Ventral lateral preoptic nucleus contains what type of neurons?
|
GABA
|
|
|
Internal capsule
|
|
|
|
What palsy results when there is bilateral lesion to the genu of the internal capsule and what are its signs?
|
?
|
|
|
What are the two relations of the anterior limb of internal capsule?
|
? Caudate nucleus and interventricular foramen
|
|
|
What happens when the posterior limb of internal capsule has a lesion?
|
Contralateral spastic paralysis, opposite side stereognosia
|
|
|
What is the medial relation of the posterior limb of internal capsule?
|
thalamus
|
|
|
What is the lateral relation of the posterior limb of internal capsule?
|
GPi
|
|
|
What happens if the Retrolentiform part of internal capsule is cut?
|
Contralateral homonymous hemianopia
|
|
|
What happens if the Sublentiform part of internal capsule is injured?
|
loss of audition
|
|
|
What are the ascending tracts that are present in the posterior limb of internal capsule?
|
Corticospinal tracts-anterior and lateral
|
|
|
What is the blood supply of the superior part of the internal capsule?
|
Middle cerebral A (lateral geniculate branches)
|
|
|
What is the blood supply of the inferior part of the anterior limb and genu of internal capsule?
|
Medial striate branches of ACA
|
|
|
What is the blood supply of the inferior part of the posterior limb of internal capsule?
|
Anterior choroidal A
|
|
|
What are the afferent and efferent tracts traversing the posterior limb of internal capsule?
|
?
|
|
|
|
|
|
|
Lecture objectives and practice questions
|
|
|
|
Name the compartments of eye where aqueous humor is present?
|
|
|
|
Of all refractory agents of the eye which one refracts maximum?
|
|
|
|
Do you have blood supply to cornea, if not why?
|
|
|
|
Why cornea to possess such a remarkable refraction?
|
|
|
|
Name all the structures that light has to pass through before incident on the retina?
|
|
|
|
Give the pathway of the nerve supply of the dilator pupilla from the hypothalamus?
|
|
|
|
Give the pathway of the nerve supply of the sphincter pupilla from the Edinger Westphal nucleus?
|
|
|
|
What are the two muscles you find in iris?
|
|
|
|
What type of receptors is present in the sphincter pupilla?
|
|
|
|
Where aqueous humor is secreted?
|
|
|
|
Give the pathway of circulation of aqueous humor?
|
|
|
|
Aqueous humor is drained into which vessel?
|
|
|
|
What is the name of the clinical condition if the pressure of aqueous humor increases?
|
|
|
|
What are the two types of Glaucoma?
|
|
|
|
What are the treatment options of open angle glaucoma?
|
|
|
|
What are the treatment options of closed angle glaucoma?
|
|
|
|
What is the afferent limb of pupillary light reflex?
|
|
|
|
What is the efferent limb of pupillary light reflex?
|
|
|
|
What is consensual light reflex?
|
|
|
|
What is the ganglion involved in the pupillary light reflex?
|
|
|
|
·
|
|
|
|
What is the afferent limb of pupillary light reflex?
|
|
|
|
What is the efferent limb of pupillary light reflex?
|
|
|
|
What is consensual light reflex?
|
|
|
|
What is the ganglion involved in the pupillary light reflex?
|
|
|
|
What are the two changes that you see in accommodation reflex?
|
|
|
|
Which muscles are contracting during the accommodation reflex and what is their nerve supply?
|
|
|
|
What is Argyll Robertson Pupil and give the clinical sign of Argyll Robertson pupil?
|
|
|
|
What is Adie’s Pupil and which part has pathology in Adie’s pupil?
|
|
|
|
What is anisocoria? And name different clinical conditions that result in anisocoria?
|
|
|
|
Which structure is injured in Marcus Gunn pupil?
|
|
|
|
What happens to the size of the pupil in Marcus Gunn pupil?
|
|
|
|
Which eye is patched in strabismic amblyopia?
|
|
|
|
Why strabismus results in blindness like in amblyopia?
|
|
|
|
What is the afferent limb of corneal reflex?
|
|
|
|
What is the efferent limb of corneal reflex?
|
|
|
|
What is Presbyopia?
|
|
|
|
What is hypermetropia and what lens is used to correct it?
|
|
|
|
What is myopia and what lens is used to correct it?
|
|
|
|
What type of eyeball can result in myopia?
|
|
|
|
What type of eyeball can result in hypermetropia?
|
|
|
|
What is the refractory power of cornea?
|
|
|
|
What is the normal size of the eyeball?
|
|
|
|
Say the length of the eyeball is 2.4 cm, and the cornea has 38 diopters, lens of how many diopters you may have to use to correct the visual defect?
|
|
|
|
For the following visual pathway defect questions, you have to find answers yourself
|
|
|
|
What happens when there is damage to the optic nerve?
|
|
|
|
What happens when there is damage to the central part of the optic chiasma?
|
|
|
|
What happens when there is a lesion of the optic tract?
|
|
|
|
What happens when there is a lesion to the temporal lobe?
|
|
|
|
What happens when there is a lesion to the parietal lobe?
|
|
|
|
What happens when there is a lesion to the superior bank of the calcarine sulcus?
|
|
|
|
What happens when there is a lesion to the inferior bank of the calcarine sulcus?
|
|
|
|
|
|
|
|
Some interesting facts about Eye a doctor should know
|
|
|
|
1. What is the primary (most powerful) focusing structure of the eye?
|
|
|
|
cornea
|
|
|
|
2. Which type of photoreceptor is most sensitive to bright light and color?
|
|
|
|
cones
|
|
|
|
3. The vitreous humor, which occupies about 80% of the eye’s interior, is composed mostly of what?(water)
|
|
|
|
Water
|
|
|
|
4. A “cataract” is an opacification of which eye structure?
|
|
|
|
Lens
|
|
|
|
5. Which eye structure determines a person’s eye color?
|
|
|
|
Iris
|
|
|
|
6. In which eye disorder does too much intraocular pressure damage optic nerve fibers?
|
|
|
|
Glaucoma
|
|
|
|
7. Which eye structure is comparable to the film of a camera because it senses light focused on it?
|
|
|
|
Retina
|
|
|
|
8. “Pink eye” is an inflammation of which eye tissue?
|
|
|
|
Conjuctiva
|
|
|
|
9. Which cranial nerve innervates four of the six extraocular muscles (medial rectus, superior rectus, inferior rectus, and inferior oblique)?
|
|
|
|
Oculomotor
|
|
|
|
10. What is the point of sharpest, most acute visual acuity within the eye?
|
|
|
|
Fovea
|
|
|
|
11. Which of these eye colors is produced by the most amount of pigment in the iris?
|
|
|
|
Brown
|
|
|
|
12. The optic nerve is known also as what cranial nerve?
|
|
|
|
Second cranial nerve
|
|
|
|
13. What is a triangular patch of blood-vessel-engorged tissue on the conjunctiva which can encroach onto the cornea and adversely affect vision?
|
|
|
|
(it is pterygium)
|
|
|
|
14. Too much near work, thereby forcing the crystalline lens of the eye to over-accommodate without providing it with sufficient rest, can result in what?
|
|
|
|
( it is called near point stress)
|
|
|
|
15. An inherited disease which gradually devastates the rods of the retina, thereby reducing night vision and ultimately resulting in “tunnel” vision, is known as what?
|
|
|
|
|
|
|
|
Retinitis pigmentosa
|
|
|
|
|
|
|
|
16. Floaters” (also known as “muscae volitantes“), which sometimes interfere with vision, can be caused by a what?
|
|
|
|
Vitreous detachment
|
|
|
|
(by the by you can see retinal detachment also in this image)
|
|
|
|
|
|
|
|
17. What test can detect early stages of macular degeneration, a hereditary ocular disease which is the leading cause of irreversible blindness among Americans 65 and older?
|
|
|
|
(Amsler grid test)
|
|
|
|
(if the lines appear broken or curved it may suggest macular degeneration)
|
|
|
|
|
|
|
|
18. Which of the following conditions can cause a temporary decrease in vision for several days or weeks, as well as pain in the eye when the eye is moved?
|
|
|
|
optic neuritis
|
|
|
|
19. A palsy of which extraocular muscle most likely will result in an esotropia (turning inward) of the affected eye?
|
|
|
|
Lateral rectus
|
|
|
|
20. In the tiny foveola, there are approximately how many cones?
|
|
|
|
About 25,000
|
|
|
|
21. Between the iris and the crystalline lens is located what?
|
|
|
|
Posterior chamber
|
|
|
|
22. The layer of the retina, containing the axons of bipolar cells and amacrine cells and the dendrites of ganglion cells, is known by what name?
|
|
|
|
Inner plexiform layer
|
|
|
|
23. What is the ring-like tendon, located in the nasal orbit, through which the superior oblique passes?
|
|
|
|
trochlea
|
|
|
|
24. As an increasing amount of light enters the eye, the pupil does what?
|
|
|
|
Constriction
|
|
|
|
25. What severely blinding disorder results from a loss of the arterial blood supply to the optic nerve of one eye?
|
|
|
|
ischemic optic neuropathy
|
|
|
|
26. What ocular tissue provides protection for the eye and serves as an attachment for the extraocular muscles which move the eye?
|
|
|
|
It is Sclera
|
|
|
|
Objectives and practice questions
|
|
|
|
Eye
|
|
|
|
What happens if fluid accumulates between pigment layer and retina?
|
|
|
|
How many layers are there in the lateral geniculate body?
|
|
|
|
Name the layers which receive the fibers from the ipsilateral eye?
|
|
|
|
Name the layers which receive the fibers from the contralateral eye?
|
|
|
|
What are the layers that receive ‘P’ pathway fibers?
|
|
|
|
What are the layers that receive ‘M’ pathway fibers?
|
|
|
|
What is the final destination of ‘M’ pathway and what clinical condition results when it is involved?
|
|
|
|
What is the final destination of ‘P’ pathway and what are the clinical signs of the lesion to this pathway?
|
|
|
|
Which cell is responsible for the generation of action potential in the retina?
|
|
|
|
Name the two photoreceptors?
|
|
|
|
Name all the cells present in the retina?
|
|
|
|
Name the three structures involved in the outer plexiform layer?
|
|
|
|
Name the three structures involved in the inner plexiform layer?
|
|
|
|
What is fovea?
|
|
|
|
What is macula lutea?
|
|
|
|
What type of photoreceptors is present in the fovea?
|
|
|
|
Which receptors are responsible for the day light and color?
|
|
|
|
Which receptors are responsible for the dim light?
|
|
|
|
What are the structures present at the blind spot?
|
|
|
|
What are distinctly absent in the blind spot?
|
|
|
|
In papilledema, in relation to what you find edema?
|
|
|
|
Name three important characteristics of cones
|
|
|
|
What are the three types of cones?
|
|
|
|
Which cones are present in the fovea?
|
|
|
|
Which particular cones are absent in fovea?
|
|
|
|
Name two characteristics of fovea which reduces the chromatic aberration?
|
|
|
|
Why color abnormalities of green and red are common in male?
|
|
|
|
Which chromosome is responsible for the blue color?
|
|
|
|
What is the common treatment of nictalopia?
|
|
|
|
|
|
|
|
Ear
|
|
|
|
What is the range of frequency that human ear is adopted to respond?
|
|
|
|
Conversational speech is equivalent to how many decibels?
|
|
|
|
Trace the auditory pathway from the spiral ganglion to the transverse Heschl’s gyrus?
|
|
|
|
What is impedance matching?
|
|
|
|
How much enhancement of pressure over the oval window is possible due to the middle ear mechanism?
|
|
|
|
What are the two muscles that help in the attenuation reflex? And what is their nerve supply?
|
|
|
|
What is the name of the central pillar of the cochlea?
|
|
|
|
What is the name of the connection between scala vestibuli and scala tympani at the apex of the modiolus?(Helicotrema)
|
|
|
|
What are the two compartments which contain the perilymph?
|
|
|
|
What is the compartment that contains the endolymph?
|
|
|
|
Which structure helps to maintain the high concentration of potassium in the endolymph?
|
|
|
|
What is endocochlear potential? And who much is that?
|
|
|
|
What membrane separates the scala media from the scala tympani?
|
|
|
|
What is the membrane over which organ of corti is situated?
|
|
|
|
What is the name of the membrane that roofs the organ of corti?
|
|
|
|
Which part of the internal ear senses the frequency?
|
|
|
|
Which part of the basilar membrane is wide and less stiff?
|
|
|
|
Which part of the basilar membrane is stiff and narrow?
|
|
|
|
Which part of the basilar membrane senses high frequency?
|
|
|
|
Which part of the basilar membrane senses low frequency?
|
|
|
|
How many inner and outer hair cells are there in the internal ear?
|
|
|
|
What type of special channels is there over the tip of cilia?
|
|
|
|
Which ion enters the interior of the cell during depolarization?
|
|
|
|
Which cells are called ‘cochlear amplifiers?
|
|
|
|
What is the range of normal loudness and how many decibels is it?
|
|
|
|
What is the range of normal frequency and what frequencies is it?
|
|
