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Gross Anatomy of the Brain

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Gross Anatomy of the Brain CRANIAL NERVES Optic nerve (II) Diencephalon Optic chiasm Optic tract Basis Midbrain pedunculi Trochlear nerve (IV) Oculomotor nerve (III) Trigeminal nerve (V) Abducens nerve (VI) Pons Facial and intermediate nerves (VII) Vestibulocochlear nerve (VIII) Pyramid Glossopharyngeal (IX) and vagus nerves (X) Hypoglossal nerve (XII) Accessory nerve (XI) Pyramidal decussation Cervical ventral roots 1 CRANIAL NERVES Diencephalon Lateral geniculate body Optic Inferior colliculus nerve (II) Trochlear nerve (IV) Midbrain Oculomotor nerve (III) Basis pedunculi Cerebellar peduncles: Trigeminal nerve (V) Superior Middle Pons Abducens nerve (VI) Inferior Facial and intermediate nerves (VII) Vestibulocochlear Pyramid nerve (VIII) Olive Glossopharyngeal (IX) Medulla and vagus nerves (X) Hypoglossal nerve (XII) Spinal accessory Cervical nerve (XI) ventral roots CRANIAL NERVE NUCLEI Mesencephalic trigeminal Motor Afferent Edinger-Westphal nucleus (N. V) nucleus (N. III) Special visceral General General and special visceral Oculomotor somatic nucleus (N. III) General General somatic visceral Special somatic Trochlear nucleus (N. IV) III III V Midbrain IV Trigeminal motor nucleus (N. V) Principal sensory trigeminal nucleus V Abducens nucleus (N. VI) (N. V) V Facial motor VI nucleus (N. VII) VIII Pons Vestibular nuclei V, VII, (N. VIII) VII IX, X VIII Superior (N. VII) IX Inferior (N. IX) IXVII Salivatory Cochlear nucleus XII nucleus (N. VIII) X Medulla Nucleus ambiguus (N. IX, X) IX, X Hypoglossal nucleus (N. XII) Solitary nucleus Dorsal motor nucleus (N. VII, IX, X) of vagus (N. X) XI Spinal cord Spinal trigeminal Accessory nucleus (N. XI) nucleus (V, VII, IX, X) CRANIAL NERVE NUCLEI Afferent: Somatic Visceral Visceral Somatic Special somatic afferent (VIII) General somatic afferent (V, VII, IX, X) General and special visceral afferent Sulcus (VII, IX, X) limitans General visceral motor (III, VII, IX, X) Special visceral motor (V, VII, IX, X, XI) General somatic motor (III, IV, VI, XII) 2 CRANIAL NERVE NUCLEI Section through superior colliculus Mesencephalic trigeminal nucleus (V) Edinger- Westphal nucleus (III) Oculomotor nucleus (III) Section through inferior colliculus Mesencephalic trigeminal Trochlear nucleus (V) nucleus (IV) CRANIAL NERVE NUCLEI Section through middle cerebellar peduncle Mesencephalic trigeminal nucleus (V) Vestibular nuclei (VIII) Principal sensory trigeminal nucleus (V) Motor trigeminal nucleus (V) Section through cochlear nuclei and the trapezoid body Abducens nucleus (VI) Cochlear nuclei (VIII) Vestibular nuclei (VIII) Spinal trigeminal nucleus (V) Facial motor nucleus (VII) BRAIN STEM RETICULAR FORMATION MLF ICP Parvocellular Magnocellular ML PYR 3 BRAIN STEM DEVELOPMENT BRAIN STEM DEVELOPMENT Sulcus limitans A Alar plate B Basal plate C Special somatic afferent General and special General visceral afferent visceral motor General somatic Special afferent visceral motor General somatic motor D Hypoglossal nucleus (XII) Vestibular nucleus (VIII) Solitary nucleus (VII, IX, X) Dorsal motor Spinal nucleus of trigeminal vagus (X) nucleus (V, VII, IX, X) Nucleus ambiguus (X) MOVEMENT CONTROL Basal Motor ganglia areas Non- motor areas Cerebellum Brain stem motor nuclei Spinal interneurons Motor neurons Movement 4 MOVEMENT CONTROL A Ventral corticospinal tract B Lateral corticospinal tract 6 6 4 4 3,1,2 Internal capsule Internal capsule Reticular and vestibular Red nucleus nuclei (magnocellular part) Rubrospinal Medial tract brain stem pathways Pyramidal decussation Lateral Ventral corticospinal corticospinal tract tract Ascending dorsal column – medial lemniscal pathway to primary sensory cortex Somatic sensory cortex Toe (postcentral gyrus) Leg Trunk Forearm and hand area SENSORY Cerebral cortex CONTROL Face Lateral sulcus Internal capsule Thalamus Ventral posterior Third ventricle lateral nucleus Midbrain Medial lemniscus Pons Medial lemniscus Medulla Gracile nucleus Cuneate nucleus Medulla Spinal trigeminal nucleus Sensory decussation Gracile fascicle Dorsal root Cuneate fascicle ganglion Spinal cord AUTONOMIC NERVOUS SYSTEM Sympathetic Projections of Projections of Parasympathetic division sympathetic parasympathetic division division division Eye Ciliary ganglion Midbrain III Lacrimal and Pterygopalatine and submaxillary ganglion Pons salivary glands VII Medulla Otic ganglion IX Superior cervical X ganglion Bronchi Cranial Middle cervical Esophagus nerves Cervical ganglion and lungs Inferior cervical ganglion Piloerector muscle Heart Artery Celiac ganglion Thoracic Sweat Liver glands Stomach Pancreas Adrenal medulla Small intestine Lumbar Large intestine, rectum Sacral Pelvic nerve Bladder leading to pelvic ganglia Sypathetic Superior Inferior chain mesenteric mesenteric Reproductive ganglion ganglion organs 5 NORADRENERGIC SYSTEM A A6 / locus ceruleus A7 A5 B CTX T HF C CC PT Cerebellum Th OB CTX S F EC DT AO RF Spinal cord CT A H LC BS DOPAMINERGIC SYSTEM A Caudate Corpus and putamen callosum Cerebellum Anterior Lateral Hippocampus cingulate septum cortex Prefrontal cortex Habenula A10 Striatum Locus ceruleus A8 Lateral parabrachial nucleus A9 Pyriform Central Entorhinal Nucleus cortex nucleus cortex accumbens (amygdala) B Olfactory bulb Thalamus A16 A13 A11 A15 Spinal cord Retina A14 A12 Pituitary A17 Median eminence SEROTONERGIC SYSTEM Cerebellum Cerebral cortex Cingulate bundle HF B7 Th CD B8 B6 B2 B4 B3 B9 B5 H B1 External Medial forebrain capsule bundle Serotonergic innervation 6 CHOLINERGIC SYSTEM Caudate Fornix and putamen Hi Ha OB Th LDT DBv BM VTA IPN LH PPT A RF MaPo Cholinergic system HISTAMINERGIC SYSTEM A Tuberomammillary nucleus B Cerebral cortex Cingulate cortex Thalamus Septum Amygdala Hypothalamus Tuberomammillary Histaminergic innervation nucleus DOPAMINERGIC SYNAPSE Presynaptic dopaminergic neuron IP3 Ca2+ D D 3 DAG PKC 3 PIP2 AC Cortical or mesolimbic – + target neuron (D2, D 3, D 4)(D1, D 5) Gi Gs ATP cAMP 7 DOPAMINERGIC SYNAPSE 1a Tyrosine Antipsychotic Increase of synthesis (L-DOPA) Can produce Tyrosine psychotic symptoms 1b Inhibition of synthesis (α-methyltyrosine) DOPA 2 Interference with vesicular storage (reserpine, Dopamine 6 tetrabenazine) Inhibition of breakdown (pargyline) 3 Stimulation of release of DA at nerve terminal (amphetamine, tyramide) MAO Autoreceptor D3 Vesicular monoamine transporter Dopamine 4 transporter 5 Blocking of DA receptors Inhibition of reuptake and autoreceptors (cocaine, amphetamine, (antipsychotics: benztropine) perphenazine, haloperidol) COMT D2 D2 MESOCORTICOLIMBIC DOPAMINERGIC SYSTEM A Midsagittal section B Coronal section Mesocortical system: Neocortex ? involved in the Nucleus negative symptoms accumbens of schizophrenia (ventral striatum) Limbic forebrain Frontal cortex Hippocampal formation Mesolimbic and mesocortical Ventral tegmental system Midbrain Mesolimbic area system: ? involved in the positive symptoms Hippocampal Ventral of schizophrenia formation tegmental area SEROTONERGIC SYSTEM A Pathways B Targets To Neocortex Caudate nucleus Thalamus Cingulum hippocampus and putamen Striatum Cingulate gyrus Neocortex Globus pallidus Nucleus accumbens (ventral Thalamus striatum) Limbic forebrain Hypothalamus Hypothalamus Olfactory and entorhinal Medial cortices forebrain Deep Midbrain bundle Amygdala cerebellar nuclei Hippocampus Cerebellar Pons Rostral cortex raphe nuclei Caudal raphe To spinal nuclei cord Raphe nuclei 8 Depressant Antidepressant A Serotonergic neurons 1 Inhibition of synthesis Tryptophan (p -chlorophenylalanine, p -propyldopacetamide) 5-OH-Tryptophan 5-HIAA 5-HT 2 Interference with vesicular storage 5-HT (reserpine, 5 tetrabenazine) 5-HT Inhibition of enzyme that oxidizes 5-HT MAO inhibitors (iproniazid, clorgyline) 3a Stimulation of MAO autoreceptor agonist 8-Hydroxy-diproplamino- tetraline (8-OH-DPAT) 4 Inhibition of reuptake Tricyclics and (imipramine, 3b selective serotonin Stimulation of 5-HT 5-HT amitryptyline, fluoxetine, reuptake inhibitors receptors as sertraline) partial agonist (lysergic acid diethylamide) 5-HT receptor B Noradrenergic neurons Tyrosine 1a hydroxylase Inhibition of synthesis Deaminated (α-methyltyrosine) products 1b DOPA Inhibition of synthesis (FLA 63) Dopamine 2 Interference with vesicular storage NE 7 (reserpine, Inhibition of enzyme tetrabenazine) that oxidizes NE MAO inhibitors (pargyline) 3 NE Stimulation of release of MAO NE at nerve terminals (amphetamine) 6 Inhibition of reuptake (desipramine) Tricyclics Receptor NM 4a 5 Stimulation of receptors Inhibition of enzyme (clonidine) that inactivates NE Inactivation inhibitor COMT (tropolone) 4b Blocking of receptors (phenoxybenzamine and phentolamine) ASCENDING AROUSAL SYSTEM 9 ASCENDING AROUSAL SYSTEM Cerebral Hippocampus Parabrachial cortex nucleus Thalamus ILT RT Locus ceruleus Basal forebrain Tuberomammillary Pedunculopontine (cholinergic system) nucleus nucleus Melanin concentrating Dorsal and hormone and orexin median raphe system nuclei Appleton & Lange DESYNCHRONISED AND SYNCHRONISED EEG A 0.2 mV 1 s B THALAMIC NEURON ACTIVITY Slow-wave sleep Waking EEG Bursts Single spikes Thalamic firing extracellular 0.5 s Bursts Na+ Single spikes Thalamic 2+ firing Ca intracellular 100 ms 10 RESPIRATORY PATTERN IN COMATOSE PATIENT A A B C D E B C D 1 min E NUCLEUS OF THE SOLITARY TRACT COORDINATES AUTONOMIC FUNCTION Periaqueductal gray matter Parabrachial nucleus Cortex Amygdala Dorsal motor vagal nucleus Hypothalamus Nucleus ambiguus Ventrolateral Nucleus of the medulla solitary tract Heart AMYGDALA AND BRAIN STEM NUCLEI COORDINATE FEAR RESPONSE 11.
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  • Lecture (6) Internal Structures of the Brainstem.Pdf

    Lecture (6) Internal Structures of the Brainstem.Pdf

    Internal structures of the Brainstem Neuroanatomy block-Anatomy-Lecture 6 Editing file Objectives At the end of the lecture, students should be able to: ● Distinguish the internal structure of the components of the brain stem in different levels and the specific criteria of each level. 1. Medulla oblongata (closed, mid and open medulla) 2. Pons (caudal and rostral). 3. Midbrain ( superior and inferior colliculi). Color guide ● Only in boys slides in Green ● Only in girls slides in Purple ● important in Red ● Notes in Grey Medulla oblongata Caudal (Closed) Medulla Traversed by the central canal Motor decussation (decussation of the pyramids) ● Formed by pyramidal fibers, (75-90%) cross to the opposite side ● They descend in the lateral white column of the spinal cord as the lateral corticospinal tract. ● The uncrossed fibers form the ventral corticospinal tract Trigeminal sensory nucleus. ● it is the larger sensory nucleus. ● The Nucleus Extends Through the whole length of the brainstem and its note :All CN V afferent sensory information enters continuation of the substantia gelatinosa of the spinal cord. the brainstem through the nerve itself located in the pons. Thus, to reach the spinal nucleus (which ● It lies in all levels of M.O, medial to the spinal tract of the trigeminal. spans the entire brain stem length) in the Caudal ● It receives pain and temperature from face, forehead. Medulla those fibers have to "descend" in what's known as the Spinal Tract of the Trigeminal ● Its tract present in all levels of M.O. is formed of descending (how its sensory and descend?see the note) fibers that terminate in the trigeminal nucleus.