NEUROANATOMY NEUROLOGY NEUROPHYSIOLOGY PART I (OT Class) CENTRAL NERVOUS SYSTEM DERIVATIVES os Ventriles [Telencephalon erebral hemispheres and [Lateral ventricle frost of basal ganglia Tensephalon alamus, pineal gland, Third ventricle hypophysis, ypothalamus, and the fesencephalon bra, substantia nigra Cerebral aqueduct ctencephalon "ons and cerebellum rth ventricle Myeleneephalon Medulla MENINGES and SPACES Arranged according to layers: 1. Dura Mater outermost 2. Subdural space ~space between the dura and arachnoid 3. Arachnoid membrane 4. Subarachnoid space ~space between the arachnoid and pia 5. Pia mater innermost DURA MATER + Aka. pachymenins + Tough fibrous strcture with an inner (meningeal) and an outer (periosteal layer + Possesses numerous sensory endings that are sensitive to stretching wich produce the sensation of headache + Numerous arteries supply the dura mater from the intemal carotid, maxillary, ‘ascending pharyngeal, ocipital, and vertebral arteries + From aclinical standpoint, the most important i the middle meningeal artery, ‘hich can be damaged in head injuries Fakx cerebri ‘+ Extends down into the longitudinal fissure between the cerebral hemispheres, Tentorium corebell! + Aroughly transverse membrane that separates the occipital lobes from the cerebellum Falx cerebell! * Projects between the cerebellar hemispheres from the inner surface ofthe ‘occipital bone to form a small triangular dural septum Diaphragma sellae ‘+ Forms an incomplete lid over the bypophysis in the sella turcica by connecting the clinoid attachments of the two sides ofthe tentorium eerebelli + The pituitary stalk passes through the opening in the diaphragmaARACHNOID MEMBRANE + Delicate avascular membrane that covers the subarachnoid space 2 Am impermeable membrane covering the brain and lying between the pia mater internally and the dura mater exterally + Thoabural space fa potential space filed bya film of fd that separates ihe dura and arachnoid membrane «The subarachnotd space is filled with CSF tht separates the arachnoid mem rane and pia mater « Sublrachnoid space becomes much wider in areas tthe base ofthe brain—the CCisterns formed by the subarachnoid space + Cisterna magna between medulla and cerebellar hemispheres Pontine cistern anterior to the pons containing the basilar artery and some veins + Chiasmatic cistern -above the optic chiasm + Suprasellar citer —above the diaphragma see 1 Tnterpeduncular cistera between cerebral peduncles Sears. fhe lateral Assure (citer of Sylvius) between frontal, temporal, and parietal labes MATER, «A thin connective tissue membrane that covers the brain surface and extends into fale and fissures and around blood vessels throughout the brain «Extends into the wansverse cerebral fissure under the corpus callosum 1 Ebsinsthe tela choroidea ofthe third and lateral ventcles and combines with the pendyma and choroid vessels to form the choroid plexus ofthese wenrsles + Pla mater arachnoid membrane = leptomeninges CLINICAL CORRELATIONS Epidural hemorrhage Vietally ways traumatic ‘Usually associated with skull facture “Tear of dural arteries, most frequently middle meningeal artery [Lends to cerebral herniation (usually subfalcine) if not promptly evacuated Lucid interval before LOC (“talk & die syndrome”) (Ct scan findings of epidural hematoma is a lenticular-shaped hematoma Subdural hemorrhage “+ collection of blood under the dura 1 CEused by a facture or trauma with tearing of “bridging” veins that pass through, the space between the cortical surfaze and the dural venous sinuses «+ CTrscan findings of subdural hematoma is a crescent-shaped hematoma Subarachnoid hemorrhage «+ Most frequent cause ruptured berry aneurysm Blood excravasating from an artery on the surface of the brain cam fill the Riperachnoid space and cause serious neurologic deficits due to mass effect, ‘vasospasm, seizutes, et. + Sudden “thunderclap headache”, and nuchal rigidityTHE SPINAL CORD, GENERAL FEATURES * Continuous with the Medulla Oblongata beginning above atthe Foramen “Magnum terminating a the Conus Medullaris inferiorly at Ll or 1.2 evel in adults Spinal cord ends just above L3 in young children Eight puirs of Cervical spinal nerves Cervical enlargement gives rise to the Brachial plexus Twelve pairs of Thoracic spinal nerves mostly innervating the trunk Five pars of Lumbar spinal nerves that give rise o the Lumbar end Lumbosaeral plexus Five pairs of Sacral spinal nerves that contribute tothe Lumbosacral plexus + One pair of Coceygeal spinal nerve + Cauca equina consists ofthe dorsal and ventral roots ofthe lumbar, sacra, and coceygeal spinal nerves + Filum Terminale extends from the tip ofthe Conus Medullaris and ataches to the distal dural sac tthe back of the eoccys Posterior (dorsal) columnDORSAL HORN Dominated by neurons that respond to sensory stimulation All incoming sensory fibers enter the dorsolateral fasciculus of Lissauer ‘VENTRAL HORN Contains Alpha and Gamma motoneurons ‘Alpe motoneurons innervate the skeletal musele (extrafusal fibers) Gamma motoneurons innervate the contractile intrafusal fibers of the musele spindle Alpha and Gamma motoneurons that innervate the flexors are posterior to those that innervate the extensors Alpha and Gamma motoneurons that innervate the proximal musculature are ‘medial to those that innervate the distal musculature + Axons ofthe isha, Gamma, and preganglionic neurons leave the cord vi the ventral roat MOTOR svsTeMs, + LMN-cell bodies originate a the anterior hom cel of the spinal cord and axons ‘exitina ventral root and joins the spinal nerve to innervate the skeletal muscle + Axons of LMN in the brainstem exit in a cranial nerve + UMN -cell bodies are found inthe Red nucleus, reticular formation, lateral vestibular nuclei of the brainstem, and most importantly inthe cerebral cortex + Axons of cortical neurons course in the CSTNEUROANATOMY NEUROLOGY NEUROPHYSIOLOGY PART 1 (OT Class) (CENTRAL NERVOUS SYSTEM DERIVATIVES os Ventricles [Telencephaton Trebral hemispheres and [Lateral ventile most of basal ganglia jencephalon Thalamus, pineal gland, [Third ventile eurohypophy sis, sypothalamus, and the |Mesencephalon fidorain, substantia nigra [Cerebral aqueduct [Metencephalon. Pons and cerebellum JFourh ventricle [Myelencephalon edulla MENINGES and SPACES Amranged according to layers 1. Dura Mater -outermost 2. Subdural space -space between the dura and arachnoid 3. Arachnoid membrane 4. Subarachnoid space ~space between the arachnoid and pia 5. Pia mater ~innermost DURA MATER + Aka. pachymeninx + Tough fibrous structure with an inner (meningeal) and an outer (periosteal) layer + Possesses numerous sensory endings that are sensitive to stretching which, procice the sensation of headache + Numerous arteries supply the dura mater from the intemal carotid, maxillary, ascending pharyngeal, oceipital, and vertebral arteries ‘+ From aclinial standpoint, the most important isthe middle meningeal artery ‘which ean be damaged in head injuries Fats cerebri + Extends down into the longitudinal fissure between the cerebral hemispheres Tentorium cerebelli + A roughly transverse membrane that separates the occipital lobes from the cerebellum Falk cerebelli + Projects between the cerebellar hemispheres ftom the inner surface ofthe ‘occipital bone to form a small triangular dura septum Diaplvogma sellae + Forms an incomplete lid over the hypophysis in the sella turciea by connecting the clinoid attachments ofthe two sides of the tentorium cerebeli +The pituitary stalk passes through the opening in the diaphragma,ARACHNOID MEMBRANE Delicate avascular membrane that covers the subarachnoid space * An impermeable membrane covering the brain and lying between the pia mater internally and the dura mater extemaly *+ The subslural space is a potential space filled by a film of fluid that separates the dura and arachnoid membrane * The subarachnoid space is filled with CSF that separates the arachnoid membrane and pia mater * Subarachnoid space becomes much wider in areas atthe base ofthe brain the cisterns (Cisterns formed by the subarachnoid space: CCisterma magna ~between medulla and cerebellar hemispheres Pontne cistern -anterior tothe pons containing the basilar artery and some veins ‘Chiasmatecistem above the optic chasm Suprasellar cistern -above the diaphragma selloe Interpeduncular cistem between cerebral peduncles ‘Cistem of the lateral fissure (istem of Sylvius) -between frontal, temporal, and parietal lobes ATER + A thin connective tissue membrane that covers the brain surface and extends into ‘ule and fissures and around blood vessels throughout the brain + Extends into the transverse cerebral fisure under the corpus callosum ‘+ Forms the tela choroidea ofthe third and lateral ventricles and combines with the {pendyma and choroid vessels to form the choroid plexus oF these ventricles + Pia mater + arachnoid membrane = leptomeninges CLINICAL CORRELATIONS Epidural hemorrhage + Virtually always traumatic + Usually associated with skull facture + Tear of dural arteries, most frequently middle meningeal artery + Leads to cerebral herniation (usually subfaleine) if not prompily evacuated + Lucid interval before LOC (“talk & die syndrome”) (CT scan findings of epidural hematoma isa lenicula-shaped hematoma Subdural hemorrhage + collection of blood under the dura + caused by a facture or tauma with tearing of “bridging” veins that pas through the space between the conical surface andthe dural venous sinuses + CT scan findings of subdural hematoma i a erescent-shaped hematoma Subarachnoid hemorrhage + Most fiequent eause -ruptured berry aneurysm + Blood extravasating from an artery on the surface ofthe beain can ill the subarachnoid space and cause serious neurologic deficits dae to mass effect, ‘vasospasm, seizures, etc, + Sudden “thunderelap headache”, and nuchal rigidity aCEREBROSPINAL FLUID FLOW LATERAL VENTRICLE Feranen ‘of Monro, 4th VENTRICLE Foramen of Magendie -Foramen of Luschka SUB-ARACHNOID ‘SPACE fr ‘Arachnoid Granulations ‘SUPERIOR SAGITTAL SINUS —> VENOUS SYSTEM[REGION SHAPE [WHITE [ANTERIORPOSTERIORILATERAL ATER [ORAY RAY Koay ‘uum korusy_fotusy arial Prat Fasc [dal bs Pen bd fetetarneceen cues fs vais en Present besa! pounpropis pecs pres ree Cl Pan wae sce (C3 Flam) Br piece al gop feast nei Irs hres lord Frcs edt —fbsanta — Praca shes fans frupot pains, fate rraandflston ales” fretnloie fem fk” frome, ype mia fools friar” fibers om ral ces tan) cel | een ae raat er a eS a So frat Fereene froupot nism, fapraessie eat ety fees” opr femetiné fronts fyrmnete accu aie fikas”—fibos bss jal joen coun (cates coret fslin)at fer flehand fmol fiscal hee hte ins = a CS evans fpoupot pain edhe rm ren fetter fies St fr forertinb props frst ee Se EE