doc. MUDr. Adriana Boleková, PhD. MVDr. Natália Hvizdošová, PhD. CENTRAL NERVOUS SYSTEM is composed from spinal cord and brain SPINAL CORD

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1 CENTRAL NERVOUS SYSTEM is composed from spinal cord and brain doc. MUDr. Adriana Boleková, PhD. MVDr. Natália Hvizdošová, PhD. SPINAL CORD cranial border: foramen magnum, pyramidal decussation, exit of first pair of spinal nerves caudal border: level of L1 L2 vertebrae medullary cone filum terminale (S2) cauda equina enlargements: cervical enlargement (C5 Th1): origin of nerves for upper extremity brachial plexus lumbosacral enlargement (L1 S2): origin of nerves for lower extremity lumbosacral plexus external features: anterior median fissure anterolateral sulcus anterior roots of spinal nn. posterolateral sulcus posterior roots of spinal nn. posterior median sulcus posterior intermediate sulcus internal features: White matter anterior funiculus (between anterior median fissure and anterolateral sulcus) lateral funiculus (between anterolateral and posterolateral sulci) posterior funiculus (between posterolateral sulcus and posterior median sulcus) fasciculus gracilis fasciculus cuneatus Gray matter anterior (ventral) horn motor function: Rexed laminae I VI lateral horn serves to visceral function: Rexed lamina VII dorsal (posterior) horn sensory information: Rexed laminae VIII IX central grey matter interneurons: around central canal Rexed lamina X Central canal cranially opens into IV. ventricle caudally expands into terminal ventricle vessels of spinal cord: Arteries: spinal brr. from surrounding arteries anterior radicular aa., posterior radicular aa.: posterior spinal aa. (in posterolateral sulci) for posterior 1/3 of spinal cord, white mater anterior spinal a. (in anterior median fissure) for anterior 2/3 of spinal cord, grey mater Veins: internal vertebral venous plexuses opens to external vertebral venous plexuses coverings and spaces of spinal cord: endorhachis periosteum of vertebral canal epidural space: fatty tissue, internal vertebral venous plexuses dura mater arachnoid mater subarachnoid space: cerebrospinal fluid pia mater

2 BRAIN Rhombencephalon (hindbrain) Myelencephalon (Medulla oblongata) Metencephalon (Pons + Cerebellum) Mesencephalon (midbrain) Prosencephalon (forebrain) Diencephalon Telencephalon Brainstem (Truncus encephali) Medulla oblongata (bulb of spinal cord) Pons Mesencephalon BRAIN STEM Medulla oblongata from pyramidal decussation (crossing of anterior corticospinal tracts) to bulbopontine sulcus (transverse groove between medulla oblongata and pons) longitudinal division: ventrally: anterior median fissure foramen cecum pyramid: contains fibers of anterior corticospinal tract anterolateral sulcus: exit of hypoglossal n. (CN XII) olive posterolateral sulcus: exit of glossopharyngeal n. (CN IX), vagus n. (CN X), accessory n. (CN XI) inferior cerebellar peduncles: connect medulla oblongata and pons dorsally: posterior median sulcus fasciculus gracilis gracile tubercle intermediate sulcus fasciculus cuneatus cuneate tubercle lower part of rhomboid fossa Pons cranial continuation of medulla oblongata structures: ventrally: bulbopontine sulcus: abducent n. (CN V.) basilar sulcus: groove on ventral surface of pons, basilar a. runs within basilar sulcus middle cerebellar peduncles: connect cerebellum to pons pontocerebellar angle (pontocerebellar trigone): exits of facial n. (CN VII) and vestibulocochlear n. (CN VIII) trigeminofacial line: forms lateral border of pons, between exits of trigeminal n. (CN V) and facial n. (CN VII),border between pons and cerebellum dorsally upper part of rhomboid fossa

3 Rhomboid fossa posterior surface of medulla oblongata and pons, forms floor of fourth ventricle structures: median sulcus of rhomboid fossa: connects central canal to cerebral aqueduct median eminence: laterally to median sulcus of rhomboid fossa sulcus limitans: laterally to median eminence, border between alar and basal plates from developmental period superior part superior fovea, locus ceruleus, facial colliculus (fibers of facial n. loop around ncl. of abducent n.) intermediate part medullary striae of rhomboid fossa vestibular area and acoustic tubercle (laterally to sulcus limitans) inferior part hypoglossal trigone: lies close to median sulcus (ncl. of hypoglossal n.) vagal trigone: laterally to hypoglossal trigone (ncl. of vagus n.) area postrema: caudally to vagal trigone inferior fovea: on top of vagal trigone Mesencephalon through all mesencephalon runs cerebral aqueduct (connects IIIrd and IVth ventricles) superior cerebellar peduncles: connect mesencephalon and cerebellum parts: cerebral peduncle: ventral to cerebral aqueduct cerebral crus (basis pedunculi): interpeduncular fossa, posterior perforating substance, exit of oculomotor n. (CN III) tegmentum: substantia nigra, red nucleus tectum: dorsal to cerebral aqueduct superior colliculi brachium of superior colliculi (part of visual pathway) inferior colliculi brachium of inferior colliculi (part of auditory pathway) exit of trochlear n. (CN IV) CEREBELLUM vermis: middle unpaired part hemisphere anterior lobe posterior lobe flocculonodular lobe external features: folia of cerebellum fissures of cerebellum: primary fissure: between anterior lobe and posterior lobe posterolateral fissure: between posterior lobe and flocculonodular lobe internal features: cerebellar cortex: gray matter tree of life (arbor vitae): white matter cerebellar nuclei: gray matter fastigial nuclei emboliform nucleus globose nuclei dentate nucleus

4 superior cerebellar peduncles: connect cerebellum to midbrain middle cerebellar peduncles: connect cerebellum to pons inferior cerebellar peduncles: connect cerebellum to medulla oblongata anatomical division of cerebellum: vermis hemisphere lingula vinculum lingulae central lobule ala of central lobule culmen quadrangular lobule primary fissure declive lobulus simplex folium superior semilunar lobule horizontal fissure tuber inferior semilunar lobule pyramis biventral lobule uvula tonsil posterolateral fissure nodulus flocculus DIENCEPHALON located upward and in front of midbrain hypothalamic sulcus: border between sensory and motor parts of diencephalon Hypothalamus primary centre of ANS, located below hypothalamic sulcus structures: mammillary body tuber cinereum infundibulum hypophysis optic chiasma optic tract Thalamus sensory above hypothalamic sulcus, the largest portion of diencephalon 'gate to consciousness', receives all sensory information (except olfactory) structures: Medial surface interthalamic adhesion (intermediate mass) medullary stria of thalamus tenia thalami Dorsal surface terminal sulcus superior thalamostriate v., terminal stria tenia choroidea choroid plexus of lateral ventricle lamina affixa anterior tubercle pulvinar Metathalamus: medial geniculate body subcortical auditory centre lateral geniculate body subcortical visual centre Epithalamus dorsomedially to thalamus, connected with limbic system structures: habenula habenular trigone habenular commissure epiphysis (pineal body) posterior commissure

5 TELENCEPHALON cerebral hemispheres: cerebral cortex gray matter medullary body white matter basal ganglia gray matter rhinencephalon and limbic systems Surfaces: superolateral, medial, and inferior surfaces Margins: superior, medial, and inferior margins Lobes: frontal, parietal, occipital, temporal lobes, and insula Poles: frontal, occipital, and temporal poles Cerebral cortex gyri and sulci Superolateral surface lateral sulcus anterior, ascending, and posterior rami central sulcus Frontal lobe precentral gyrus precentral sulcus superior frontal gyrus superior frontal sulcus middle frontal gyrus inferior frontal sulcus inferior frontal gyrus orbital part anterior ramus of lateral sulcus triangular part ascending ramus of lateral opercular part posterior ramus of lateral sulcus Parietal lobe postcentral gyrus postcentral sulcus superior parietal lobule intraparietal sulcus inferior parietal lobule supramarginal gyrus: around end of posterior ramus of lateral sulcus angular gyrus: around end of superior temporal sulcus Occipital lobe occipital gyri transverse occipital sulcus lunate sulcus preoccipital notch Temporal lobe superior temporal gyrus transverse temporal gyri superior temporal sulcus Insula middle temporal gyrus inferior temporal sulcus inferior temporal gyrus limen of insula circular sulcus long gyrus central sulcus of insula short gyri

6 Medial surface of telencephalon medial frontal gyrus paracentral lobule precuneus parietooccipital sulcus cuneus calcarine sulcus cingulate sulcus cingulate gyrus isthmus of cingulate gyrus sulcus of corpus callosum corpus callosum rostrum, genu, body, splenium septum pellucidum laminae and cave of septum pellucidum fornix column, body, and crus of fornix paraterminal gyrus subcallosal area Inferior surface of telencephalon straight gyrus olfactory sulcus olfactory bulb olfactory tract medial and lateral olfactory striae olfactory trigone anterior perforating substance optic n. (CN II) optic chiasma optic tract orbital gyri orbital sulci hippocampal sulcus uncus of parahippocampal gyrus parahippocampal gyrus lingual gyrus collateral sulcus rhinal sulcus medial occipitotemporal gyrus occipitotemporal sulcus lateral occipitotemporal gyrus Functional cortical areas: Brodmannꞌs cytoarchitectonic map (1907) motor and sensory Homunculus motor areas in frontal lobe sensory areas in parietal, occipital, and temporal lobes cortical areas: primary: exact function, somatotopic organisation secondary: close to primary areas, less detail organisation, gnostic function association (tertiary): close to secondary areas, analysis and synthesis of information individual consciousness and personality Dominance of hemisphere left hemisphere analytic thinking, logic, mathematic, languages, science for right-handers and 1/2 of left-handers right hemisphere holistic thinking, intuition, creativity, music, art for 1/2 of left-handers Medullary body white matter myelinated nerve fibers, have origin or/and termination in cerebral cortex semioval centre in horizontal section between cortex and basal ganglia corona radiata below semioval centre, above of corpus callosum internal capsule between basal ganglia and thalamus corpus callosum radiation of corpus callosum, forceps major and forceps minor

7 Basal ganglia masses of gray mater, initiation and control of voluntary movements inhibition of involuntary activity, revision of information from primary motor cortex caudate ncl. head, body, and tail of caudate ncl. lentiform ncl. globus pallidus lateral (external) and medial (internal) putamen claustrum amygdaloid body (amygdala) striatum = caudate ncl. + putamen lentiform ncl. = putamen + globus pallidus corpus striatum = caudate ncl. + lentiform ncl. Basal ganglia are separated by bundles of white matter: internal capsule between head of caudate ncl. (in front) + thalamus (behind) lentiform ncl. V shaped in horizontal section: anterior limb, genu and posterior limb external capsule between putamen and claustrum extreme capsule between claustrum and cortex of insula Olfactory system olfactory bulb olfactory tract medial and lateral olfactory striae olfactory trigone anterior perforating substance Piriform lobe: primary olfactory cortex piriform area in uncus of parahippocampal gyrus in temporal lobe: prepiriform area + periamygdalar area secondary olfactory cortex enthorinal area in parahippocampal gyrus in temporal lobe orbitofrontal cortex in frontal lobe Limbic system functional system of cortical and subcortical neurons Limbic lobe: septum cingulate gyrus parahippocampal gyrus amygdala border between cortical areas and subcortical nuclei (limbus) emotions, behaviour, learning, memory mind and consciousness instincts connects with hypothalamus, expresses by ANS not only parts of telencephalon, but also parts of diencephalon and mesencephalon telencephalon: cortical areas: hippocampal formation, septum Limbic association cortex: orbitofrontal cortex, cingulate and parahippocampal gyri, entorhinal area subcortical areas: amygdala, basal ganglia diencephalon: thalamus anterior ncl., mediodorsal ncl. (associating ncl.) hypothalamus mammillary body, ventromedial ncl. epithalamus habenular ncll. (connect with olfactory system) mesencephalon: reticular formation Papez circuit hippocampus fornix mammillary body anterior ncl. of thalamus cingulate gyrus hippocampus

8 Hippocampal formation learning, memory hippocampus dentate gyrus: medially to hippocampus subiculum: under hippocampus, on upper part of parahippocampal gyrus Septum verum (septum) positive emotions, pleasure, releases serotonin (like drugs, sex) Septal area: paraterminal gyrus subcallosal area Amygdala (amygdaloid body) negative emotions: aggression, anger, anxiety, fear unconscious memory from early childhood when hippocampus is still immature VESSELS AND DURAL SINUSES Arteries of brain Telencephalon is supplied by: posterior cerebral a. mostly inferior surface of hemisphere and pons middle cerebral a. mostly superolateral surface of hemisphere anterior cerebral a. mostly medial surface of hemisphere Arterial circle of Willis (circulus arteriosus cerebri): cerebral aa. cortex and central aa. deep parts provides multiple paths for blood to supply brain if any of arteries are constricted anterior communicating a. (one): between two anterior cerebral aa. posterior communicating a. (two): between posterior cerebral a. and internal carotid a. (or middle cerebral a.) vertebral a. posterior inferior cerebellar a. basilar a.: from connection of two vertebral aa. for brainstem and cerebellum anterior inferior cerebellar a. pontine and mesencephalic aa. superior cerebellar a. posterior cerebral a. posterior communicating a. internal carotid a. anterior cerebral a. anterior communicating a. middle cerebral a. Veins of brain have no valves superficial cerebral vv. in subarachnoid space, drain cerebral cortex superior and inferior cerebral vv. superior and inferior anastomotic vv. superficial and deep middle cerebral vv. deep cerebral vv. drain internal structures of brain internal cerebral v. in choroid tela of IIIrd ventricle superior thalamostriate v. anterior septal v. superior choroidal v. basal v. drains brainstem, opens to great cerebral v. great cerebral v. below splenium of corpus callosum, from two internal cerebral vv.

9 Dural sinuses between two layers of dura matter Confluence of sinuses: superior sagittal sinus straight sinus occipital sinus transverse sinus Origin of internal jugular v. in jugular foramen from: sigmoid sinus superior and inferior petrosal sinus others: inferior sagittal sinus sphenoparietal sinus cavernous sinus BRAIN VENTRICLES filled by cerebrospinal fluid made by choroid plexus (from arachnoid mater) IVth ventricle unpaired ventricle in rhombencephalon floor: rhomboid fossa roof: superior medullary velum (frenulum of superior medullary velum) cerebellum fastigium (highest point in roof of IVth ventricle) inferior medullary velum: choroid tela and choroid plexus of IVth ventricle median aperture of IVth ventricle (unpaired), obex laterally: lateral recess of IVth ventricle lateral aperture of IVth ventricle (paired) upward: cerebral aqueduct downward: central canal Cerebral aqueduct: along midbrain, connects IVth and IIIrd ventricles IIIrd ventricle unpaired ventricle located in diencephalon and partially in telencephalon is connected to lateral ventricles through interventricular foramens roof: choroid tela and choroid plexus of IIIrd ventricle in front: lamina terminalis, anterior commissure floor: optic recess, optic chiasma, infundibular recess (infundibulum), tuber cinereum, mammillary body behind: posterior commissure, pineal recess, habenular commissure, suprapineal recess laterally: medial surface of thalamus (medullary stria, choroid tenia, interthalamic adhesion, hypothalamic sulcus, interventricular foramen, column of fornix) Recesses of IIIrd ventricle: optic recess in front of optic chiasma infundibular recess above stalk of hypophysis suprapineal recess above pineal body pineal recess into pineal body Lateral ventricle paired, in both hemispheres, in all four lobes of telencephalon communicate with the IIIrd ventricle through interventricular foramen Anterior (frontal) horn: septum pellucidum, head of caudate ncl., rostrum and genu of corpus callosum

10 Central part (in parietal lobe): body of caudate ncl., lamina affixa of thalamus, body of fornix, body of corpus callosum Posterior (occipital) horn: bulb of posterior horn, calcar avis, collateral trigone Inferior (temporal) horn: collateral eminence, collateral trigone, choroid glomus in bottom of inferior horn lies hippocampus pes hippocampi, hippocampal digitations, fimbria of hippocampus fimbria of fornix, dentate gyrus COVERINGS OF BRAIN Dura mater tough fibrous membrane, toughly adherent to skull forms duplicatures into skull cavity: falx cerebri between two cerebral hemispheres falx cerebelli between two cerebellar hemispheres tentorium cerebelli between cerebellum and occipital lobe sellar diaphragm covers sella turcica, has opening only for stalk of hypophysis Arachnoid mater soft translucent membrane, has no vessels and no nerves arachnoid granulations protrude to dural sinuses for absorption of cerebrospinal fluid subarachnoid space between arachnoid and pia maters, filled by cerebrospinal fluid and vessels subarachnoid cisterns extension of subarachnoid space, filled by cerebrospinal fluid the biggest is: cerebellomedullary cistern (cisterna magna) others: cistern of lateral fossa, interpeduncular cistern, pontine cistern, chiasmatic cistern, quadrigeminal cistern, pericallosal cistern, cisterna ambiens Pia mater thin, highly vascular membrane closely adherent to brain surface follows brain surface, gyri and sulci choroid plexus NERVE PATHWAYS white mater, myelinated nerve fibers: Association tracts: connect various areas in same hemisphere, ypsilaterally long intracortical fibers: inferior and superior longitudinal fascicles, cingulum, frontooccipital fasciculus, uncinate and arcuate fasciculi short subcortical fibers: between two neighbouring gyri, U-fibers Commissural tracts: connect same areas between two hemispheres, contralaterally corpus callosum, anterior commissure, posterior commissure, habenular commissure, commissure of fornix Projection tracts: connect areas of various levels of CNS, cortical areas subcortical areas Ascending fibers = sensory = afferent = corticopetal = directed to upper centers Descending fibers = motor = efferent = corticofugal = directed to lower centers direct sensory pathways, indirect sensory pathways direct motor pathways, indirect motor pathways PROJECTION TRACTS Ascending tracts General sensory tracts: from skin and movement system 1st neuron is inside of sensory ganglion of spinal or cranial nerve Special sensory tracts: from specialised sensory organs

11 Direct sensory pathways: conscious information A. General sensation: system of 3 neurons, 2nd neuron crosses, termination in sensory cerebral cortex superficial sensation = exteroception from skin: epicritic (fine) sensation: fine touch, discriminative sensation, vibration, recognition protophatic (crude) sensation: touch and pressure, pain and temperature deep sensation proprioception from joints, tendons, and muscles movement sense a) Sensory pathways from neck, trunk and limbs general sensation: Dorsal column pathway = main sensory pathway = spino-bulbo-thalamo-cortical tract epicritic and proprioceptive sensation Anterior spinothalamic tract protophatic sensation: touch and pressure Lateral spinothalamic tract protophatic sensation: urgent pain and temperature Spinoreticular tract slow and diffuse pain Spinotectal tract (has only 2 neurons) spinovisual reflexes b) Sensory pathways from head: Trigeminothalamic tract orofacial epicritic and protophatic sensation orofacial proprioception B. Special sensation Visual pathway and collaterals from visual pathway: Pathway of pupillary contraction and accommodation Pathway of pupillary dilatation Acoustic (auditory) pathway Vestibular pathway Gustatory (taste) pathway Olfactory pathway Indirect sensory pathways unconscious information, system of 2 neurons, termination in cerebellum coordination of movement, posture, and balance Posterior and anterior spinocerebellar tracts: information from lower half of body Cuneocerebellar tract: information from upper half of body Descending tracts Direct motor pathways: conscious motor activity of skeletal muscles Motor pathways to muscles of neck, trunk and limbs: Corticospinal (pyramidal) pathway the youngest pathway phylogenetically, upper motoneuron: in cerebral cortex, lower motoneuron: in anterior horn of spinal cord Lateral corticospinal tract: 80% of fibers cross in pyramidal decussation, run in lateral funiculus of spinal cord to muscles of limbs Anterior corticospinal tract: 20% of fibers cross in anterior commissure of spinal cord run in anterior funiculus of spinal cord to muscles of trunk Motor pathways to muscles of head and neck: Corticonuclear tract conscious movements of head and neck, facial expression, chewing, speech, upper motoneuron: cerebral cortex; lower motoneuron: nuclei of cranial nerves Indirect motor pathways (extrapyramidal) old pathways phylogenetically, unconscious motor activity, more upper motoneurons: ncl. ruber, black substance, reticular formation, vestibular ncll., tectum; lower motoneuron: motor nuclei in anterior horn of spinal cord and of cranial nerves basal ganglia modifying system, information from sensory cerebral cortex modulates unconscious motor activity from cerebral cortex, involuntary reflexes cerebellum controlling system, coordinate postural, supporting, and locomotor mechanism