DOCSLIB.ORG

Chapter 12 Central Nervous System

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Chapter 12 Central Nervous System CHAPTER 12 CENTRAL NERVOUS SYSTEM Copyright © 2010 Pearson Education, Inc. CENTRAL NERVOUS SYSTEM Embryonic Development Copyright © 2010 Pearson Education, Inc. Figure 12.1 Development of the neural tube from embryonic ectoderm (1 of 4). Surface Head ectoderm Neural plate Tail 1 The neural plate forms from surface ectoderm. Copyright © 2010 Pearson Education, Inc. Figure 12.1 Development of the neural tube from embryonic ectoderm (2 of 4). Neural folds Neural groove 2 The neural plate invaginates, forming the neural groove, flanked by neural folds. Copyright © 2010 Pearson Education, Inc. Figure 12.1 Development of the neural tube from embryonic ectoderm (3 of 4). Neural crest 3 Neural fold cells migrate to form the neural crest, which will form much of the PNS and many other structures. Copyright © 2010 Pearson Education, Inc. Figure 12.1 Development of the neural tube from embryonic ectoderm (4 of 4). Head Surface ectoderm Neural tube Tail 4 The neural groove becomes the neural tube, which will form CNS structures. Copyright © 2010 Pearson Education, Inc. Neural tube formation involves all of these stages except… 1) Neural plate 2) Neural ring 3) Neural groove 4) Surface ectoderm 5) Neural tube Copyright © 2010 Pearson Education, Inc. Figure 12.2 Embryonic development of the human brain. (a) (b) Primary brain (c) Secondary brain (d) Adult brain (e) Adult Neural vesicles vesicles structures neural tube canal regions Cerebrum: cerebral Lateral hemispheres (cortex, Telencephalon ventricles white matter, basal nuclei) Anterior Prosencephalon Diencephalon (rostral) (forebrain) Diencephalon (thalamus, hypothalamus, Third ventricle epithalamus), retina Mesencephalon Cerebral Mesencephalon Brain stem: midbrain (midbrain) aqueduct Rhombencephalon Metencephalon Brain stem: pons (hindbrain) Cerebellum Fourth ventricle Myelencephalon Brain stem: medulla Posterior oblongata (caudal) Spinal cord Central canal Copyright © 2010 Pearson Education, Inc. Which of these adult brain structures is derived from the prosencephalon? 1) Brain stem 2) Cerebellum 3) Cerebrum 4) All of the above Copyright © 2010 Pearson Education, Inc. CENTRAL NERVOUS SYSTEM Regions and Organization Copyright © 2010 Pearson Education, Inc. Figure 12.3d Effect of space restriction on brain development. Cerebral hemisphere Diencephalon Cerebellum Brain stem • Midbrain • Pons • Medulla (d) Birth oblongata Copyright © 2010 Pearson Education, Inc. Figure 12.4 Pattern of gray and white matter in the CNS (highly simplified). Central cavity Cortex of gray matter Migratory Inner gray pattern of matter neurons Cerebrum Outer white Cerebellum matter Gray matter Region of cerebellum Central cavity Inner gray matter Outer white matter Gray matter Brain stem Central cavity Outer white matter Inner gray matter Spinal cord Copyright © 2010 Pearson Education, Inc. CENTRAL NERVOUS SYSTEM Ventricles Copyright © 2010 Pearson Education, Inc. Figure 12.5 Ventricles of the brain. Lateral ventricle Septum pellucidum Anterior horn Posterior horn Inferior horn Interventricular Lateral foramen aperture Third ventricle Median aperture Inferior horn Lateral Cerebral aqueduct aperture Fourth ventricle Central canal (a) Anterior view (b) Left lateral view Copyright © 2010 Pearson Education, Inc. White matter represents… 1) High density areas of neuron cell bodies 2) Muscle 3) Blood vessels 4) High density areas of unmyelinated axons 5) High density areas of myelinated axons Copyright © 2010 Pearson Education, Inc. True or false: The central canal of the spinal Cord is continuous with the ventricles of the Brain. 1) True 2) False Copyright © 2010 Pearson Education, Inc. CENTRAL NERVOUS SYSTEM Cerebral Hemispheres: Cerebral Cortex Copyright © 2010 Pearson Education, Inc. Figure 12.6a Lobes and fissures of the cerebral hemispheres. Precentral Central gyrus sulcus Postcentral Frontal gyrus lobe Parietal lobe Parieto-occipital sulcus (on medial surface of hemisphere) Lateral sulcus Occipital lobe Temporal lobe Transverse cerebral fissure Cerebellum Pons Fissure Medulla oblongata (a deep Spinal cord sulcus) Gyrus Cortex (gray matter) Sulcus White matter (a) Copyright © 2010 Pearson Education, Inc. Figure 12.6b Lobes and fissures of the cerebral hemispheres. Central Frontal lobe sulcus Gyri of insula Temporal lobe (pulled down) (b) Copyright © 2010 Pearson Education, Inc. Figure 12.6c Lobes and fissures of the cerebral hemispheres. Anterior Longitudinal Frontal lobe fissure Cerebral veins and arteries Parietal covered by lobe arachnoid mater Left cerebral Right cerebral hemisphere hemisphere Occipital lobe (c) Posterior Copyright © 2010 Pearson Education, Inc. Figure 12.7 Functional neuroimaging (fMRI) of the cerebral cortex. Central sulcus Longitudinal Left frontal Left temporal Areas active fissure lobe lobe in speech and hearing (fMRI) Copyright © 2010 Pearson Education, Inc. Figure 12.8a Functional and structural areas of the cerebral cortex. Motor areas Central sulcus Sensory areas and related Primary motor cortex association areas Premotor cortex Primary somatosensory cortex Frontal eye field Somatic Somatosensory sensation association cortex Broca’s area Gustatory cortex (outlined by dashes) Taste (in insula) Prefrontal cortex Working memory Wernicke’s area for spatial tasks (outlined by dashes) Executive area for task management Working memory for Primary visual object-recall tasks cortex Vision Solving complex, Visual multitask problems association area Auditory association area Hearing Primary auditory cortex (a) Lateral view, left cerebral hemisphere Primary motor cortex Motor association cortex Primary sensory cortex Sensory association cortex Multimodal association cortex Copyright © 2010 Pearson Education, Inc. Figure 12.8b Functional and structural areas of the cerebral cortex. Cingulate Primary Premotor cortex gyrus motor cortex Central sulcus Corpus Primary somatosensory callosum cortex Frontal eye field Parietal lobe Prefrontal Somatosensory cortex association cortex Parieto-occipital sulcus Processes emotions Occipital related to personal lobe and social interactions Visual Orbitofrontal association area cortex Olfactory bulb Olfactory tract Primary Fornix visual cortex Temporal lobe Uncus Calcarine sulcus Primary Parahippocampal olfactory cortex gyrus (b) Parasagittal view, right hemisphere Primary motor cortex Motor association cortex Primary sensory cortex Sensory association cortex Multimodal association cortex Copyright © 2010 Pearson Education, Inc. Figure 12.9 Body maps in the primary motor cortex and somatosensory cortex of the cerebrum. Posterior Motor Sensory Motor map in Anterior Sensory map in precentral gyrus postcentral gyrus Toes Genitals Jaw Tongue Primary motor Primary somato- cortex sensory cortex Intra- Swallowing (precentral gyrus) (postcentral gyrus) abdominal Copyright © 2010 Pearson Education, Inc. Quiz Q1: All of these are true of the primary motor cortex except it… 1) Is located anterior to the central sulcus 2) Is located on the precentral gyrus 3) Controls voluntary muscle movement 4) Coordinates repeated/learned complex muscle movements Copyright © 2010 Pearson Education, Inc. Quiz Q2: The sensory homunculus has the fingers mapped to a large area of the brain because… 1) The fingers have a very large surface area 2) The fingers have lots of muscles required to move them 3) The fingers contain many sensory receptors 4) All of the above Copyright © 2010 Pearson Education, Inc. Quiz Q3: True or false: The neural crest develops into the central nervous system. 1) True 2) False Copyright © 2010 Pearson Education, Inc. Quiz Q4: Information from the premotor cortex mostly gets sent to… 1) muscles directly. 2) the primary somatosensory cortex 3) the somatosensory association cortex 4) the primary motor cortex Copyright © 2010 Pearson Education, Inc. Quiz Q5: Gray matter includes… 1) myelinated axons 2) neuron cell bodies 3) Schwann cells 4) ganglia Copyright © 2010 Pearson Education, Inc. Figure 12.10 Types of fiber tracts in white matter. Longitudinal fissure Association fibers Superior Lateral Commissural fibers (corpus callosum) ventricle Corona Basal nuclei radiata • Caudate • Putamen • Globus Fornix pallidus Internal Thalamus capsule Gray matter Third White matter ventricle Projection Pons fibers Decussation Medulla oblongata of pyramids (a) (b) Copyright © 2010 Pearson Education, Inc. Figure 12.11a Basal nuclei. Fibers of corona radiata Caudate nucleus Thalamus Lentiform Tail of Corpus nucleus caudate striatum • Putamen • Globus pallidus nucleus (deep to putamen) Projection fibers run deep to (a) lentiform nucleus Copyright © 2010 Pearson Education, Inc. Figure 12.11b Basal nuclei (1 of 2). Anterior Cerebral cortex Cerebral white matter Corpus callosum Anterior horn of lateral ventricle Caudate nucleus Putamen Globus Lentiform pallidus nucleus Thalamus Tail of caudate nucleus Third ventricle Inferior horn of lateral ventricle (b) Posterior Copyright © 2010 Pearson Education, Inc. Figure 12.11b Basal nuclei (2 of 2). Cerebral cortex Cerebral white matter Corpus callosum Anterior horn of lateral ventricle Caudate nucleus Lentiform nucleus Thalamus Third ventricle Inferior horn of lateral ventricle (b) Copyright © 2010 Pearson Education, Inc. Basal nuclei are… 1) Part of the cerebral cortex 2) Part of the cerebral hemispheres 3) Gray matter 4) 2 and 3 only 5) All of the above Copyright © 2010 Pearson Education, Inc. CENTRAL NERVOUS SYSTEM Cerebral Hemispheres: Lateralization and Contralateralization Copyright © 2010 Pearson Education, Inc. CENTRAL NERVOUS
Load more

Recommended publications
  • Frontal Lobe Anterior Corpora Commissure Quadrigemina Superior Colliculus Optic Chiasm Inferior Colliculus
    Chapter 16 The Nervous System The Brain and Cranial Nerves Lecture Presentation by Steven Bassett Southeast Community College © 2015 Pearson Education, Inc. Introduction • The brain is a complex three-dimensional structure that performs a bewildering array of functions • Think of the brain as an organic computer • However, the brain is far more versatile than a computer • The brain is far more complex than the spinal cord • The brain consists of roughly 20 billion neurons © 2015 Pearson Education, Inc. An Introduction to the Organization of the Brain • Embryology of the Brain • The CNS begins as a neural tube • The lumen of the tube (neurocoel) is filled with fluid • The lumen of the tube will expand thus forming the various ventricles of the brain • In the fourth week of development, the cephalic area of the neural tube enlarges to form: • Prosencephalon • Mesencephalon • Rhombencephalon © 2015 Pearson Education, Inc. Table 16.1 Development of the Human Brain © 2015 Pearson Education, Inc. An Introduction to the Organization of the Brain • Embryology of the Brain (continued) • Prosencephalon eventually develops to form: • Telencephalon forms: • Cerebrum • Diencephalon forms: • Epithalamus, thalamus, and hypothalamus. © 2015 Pearson Education, Inc. Table 16.1 Development of the Human Brain © 2015 Pearson Education, Inc. An Introduction to the Organization of the Brain • Embryology of the Brain (continued) • Mesencephalon • Does not subdivide • Becomes the midbrain © 2015 Pearson Education, Inc. Table 16.1 Development of the Human Brain © 2015 Pearson Education, Inc. An Introduction to the Organization of the Brain • Embryology of the Brain (continued) • Rhombencephalon • Eventually develops to form: • Metencephalon: forms the pons and cerebellum • Myelencephalon: forms the medulla oblongata © 2015 Pearson Education, Inc.
    [Show full text]
  • How Does the Human Brain Differentiate? —Normal and Abnormal Development—
    Forum Forma, 27, S29–S31, 2012 How does the Human Brain Differentiate? —Normal and Abnormal Development— Yoshihiro Fukui Department of Anatomy and Developmental Neurobiology, University of Tokushima Graduate School, Institute of Health Biosciences, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan E-mail address: [email protected] (Received January 24, 2012; Accepted March 17, 2012) Keywords: Neural Tube, Brain Vesicle, Cerebrospinal Fluid, Hydrocephalus, Anencephaly, Microcephaly 1. Three Primary Brain Vesicles Convert into Five Sec- 2. Development of the Brain Ventricular System ondary Brain Vesicles The expanded primitive ventricles formed by the neural The central nervous system (CNS) appears during the 3rd canal in the secondary brain vesicles give rise to the ven- week as a neural plate growing out from the ectoderm of tricular system of the brain (Fig. 2). The ventricles of the the germ disc. The lateral edges elevate to form the neural brain include the lateral, third, and fourth ventricles. The folds, and finally fuse, forming the neural tube. Neurula- two lateral ventricles communicate through the interven- tion begins on day 22, and the cranial neuropore, which is tricular foramina (of Monro) with the third ventricle. The an opening at anterior end of the embryonic neural canal, third ventricle is connected to the fourth ventricle by the closes on day 24. The future eyes appear as outpouchings cerebral aqueduct (aqueduct of Sylvius). The fourth ven- from the forebrain neural folds by day 22. Before neu- tricle in turn is continuous with the narrow central canal of rulation begins, the primordia of the three primary brain the spinal cord and, through the three foramina in its roof, vesicles are visible as broadenings in the neural plate as with the subarachnoid space.
    [Show full text]
  • Neuroanatomy Dr
    Neuroanatomy Dr. Maha ELBeltagy Assistant Professor of Anatomy Faculty of Medicine The University of Jordan 2018 Prof Yousry 10/15/17 A F B K G C H D I M E N J L Ventricular System, The Cerebrospinal Fluid, and the Blood Brain Barrier The lateral ventricle Interventricular foramen It is Y-shaped cavity in the cerebral hemisphere with the following parts: trigone 1) A central part (body): Extends from the interventricular foramen to the splenium of corpus callosum. 2) 3 horns: - Anterior horn: Lies in the frontal lobe in front of the interventricular foramen. - Posterior horn : Lies in the occipital lobe. - Inferior horn : Lies in the temporal lobe. rd It is connected to the 3 ventricle by body interventricular foramen (of Monro). Anterior Trigone (atrium): the part of the body at the horn junction of inferior and posterior horns Contains the glomus (choroid plexus tuft) calcified in adult (x-ray&CT). Interventricular foramen Relations of Body of the lateral ventricle Roof : body of the Corpus callosum Floor: body of Caudate Nucleus and body of the thalamus. Stria terminalis between thalamus and caudate. (connects between amygdala and venteral nucleus of the hypothalmus) Medial wall: Septum Pellucidum Body of the fornix (choroid fissure between fornix and thalamus (choroid plexus) Relations of lateral ventricle body Anterior horn Choroid fissure Relations of Anterior horn of the lateral ventricle Roof : genu of the Corpus callosum Floor: Head of Caudate Nucleus Medial wall: Rostrum of corpus callosum Septum Pellucidum Anterior column of the fornix Relations of Posterior horn of the lateral ventricle •Roof and lateral wall Tapetum of the corpus callosum Optic radiation lying against the tapetum in the lateral wall.
    [Show full text]
  • Is Composed from Spinal Cord and Brain
    doc. MUDr. Adriana Boleková, PhD. MVDr. Natália Hvizdošová, PhD. CENTRAL NERVOUS SYSTEM – is composed from spinal cord and brain 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
    [Show full text]
  • Brachycephaly and Cerebrospinal Fluid Disorders
    life Review The Need for Head Space: Brachycephaly and Cerebrospinal Fluid Disorders Clare Rusbridge 1,2,* and Penny Knowler 1 1 Faculty of Health & Medical Sciences, School of Veterinary Medicine, University of Surrey, Guildford GU2 7AL, UK; [email protected] 2 Fitzpatrick Referrals, Godalming GU7 2QQ, UK * Correspondence: [email protected] Abstract: Brachycephalic dogs remain popular, despite the knowledge that this head conformation is associated with health problems, including airway compromise, ocular disorders, neurological dis- ease, and other co-morbidities. There is increasing evidence that brachycephaly disrupts cerebrospinal fluid movement and absorption, predisposing ventriculomegaly, hydrocephalus, quadrigeminal cistern expansion, Chiari-like malformation, and syringomyelia. In this review, we focus on cere- brospinal fluid physiology and how this is impacted by brachycephaly, airorhynchy, and associated craniosynostosis. Keywords: ventriculomegaly; hydrocephalus; Chiari malformation; syringomyelia; canine; cran- iosynostosis; supracollicular fluid collection; quadrigeminal cistern; lateral aperture; sleep disordered breathing; brachycephalic obstructive airway disease 1. Introduction Brachycephalic dogs and cats have proved to be increasingly popular since they Citation: Rusbridge, C.; Knowler, P. were introduced to Europe in Victorian times. This rising popularity defies a high preva- The Need for Head Space: lence of conformation-related morbidity, including breathing, ocular, and neurological Brachycephaly and Cerebrospinal disorders [1,2]. Brachycephaly in domestic pets is a consequence of selecting for juvenile Fluid Disorders. Life 2021, 11, 139. characteristics of a flattened face and a rounded head [3]. Calvarial doming associated https://doi.org/10.3390/life11020139 with wide zygomatic arches and a wide, flattened, or convex palate is compensation for premature closure of skull-base sutures, including the basispheno-presphenoid syn- Academic Editor: Edgar Lehr chondrosis and spheno-occipital synchondrosis [4,5].
    [Show full text]
  • Redalyc.Magendie and Luschka. Holes in the 4 Th Ventricle
    Dementia & Neuropsychologia ISSN: 1980-5764 [email protected] Associação Neurologia Cognitiva e do Comportamento Brasil Engelhardt, Eliasz Magendie and Luschka. Holes in the 4 th ventricle Dementia & Neuropsychologia, vol. 10, núm. 3, julio-septiembre, 2016, pp. 254-258 Associação Neurologia Cognitiva e do Comportamento São Paulo, Brasil Available in: http://www.redalyc.org/articulo.oa?id=339547442015 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Dement Neuropsychol 2016 September;10(3):254-258 History Note Magendie and Luschka Holes in the 4th ventricle Eliasz Engelhardt1 ABSTRACT. Cerebrospinal fluid (CSF) is a complex liquid formed mainly by the choroid plexuses. After filling the ventricular system where it circulates, CSF flows out to the subarachnoid spaces through openings in the 4th ventricle. Following numerous studies on CSF pathways, these openings were first discovered in the 19th century by two notable researchers, François Magendie and Hubert von Luschka, who described the median and lateral openings subsequently named after them. Even after the studies of Axel Key and Gustav Magnus Retzius confirming these openings, their existence was questioned by many anatomists, yet acknowledged by others. Finally gaining the acceptance of all, recognition of the holes endures to the present day. Interest in these openings may be attributed to the several congenital or acquired pathological conditions that may affect them, usually associated with hydrocephalus. We report some historical aspects of these apertures and their discoverers.
    [Show full text]
  • Brain Stem  Consists: - Medulla Oblongata - Pons - Midbrain (Mesencephalon)
    Brain Stem Consists: - Medulla oblongata - Pons - Midbrain (Mesencephalon) Lies upon the basal portion of occipital bone (clivus) and is connected to cerebellum rostral : diencephalon caudal : spinal cord Contains numerous ascending and descending fibre tracts Brain stem nuclei receive fibres from or sent fibres into cranial nerves (III-XII) attach to the surface of the brain stem cranial nerve nuclei Ascenden and Descenden Pathway of Brain Stem Ascenden Descenden Lemniscus medialis Traktus corticospinalis Tractus spinothalamicus Tractus corticonuclearis Lemniscus trigeminalis Corticopontine fibres Lemniscus lateralis Tractus rubrospinalis Reticularis fibres system Tractus tectospinalis Fasciculus longitudinalis medialis Fasciculuc longitudinal medialis Pedunculus cerebellaris superior Tractus vestibulospinalis Pedunculus cerebellaris inferior Tractus reticulospinalis Secondary vestibularis fibres Tractus tegmentalis centralis Secondary gustatorius fibres Tractus descenden N.V Brain Stem Contains a complex and heterogeneous matrix of neurones reticular formation functions : - control over the level of consciousness - the perception of pain - regulation of the cardiovascular and respiratory systems It also has extensive connections with cranial nerve nuclei, cerebellum, brain stem and spinal motor mechanisms movement, posture and muscle tone Dorsal Surface (External Feature) Peduncles Dorsal median sulcus Dorsal columns (fasciculi gracilis and cuneatus) Gracile and cuneate tubercles (nuclei gracilis and cuneatus) Fossa rhomboidea
    [Show full text]
  • Midterm Exam 2014
    9.14_2014 Midterm Exam NAME KEY Class 19 1) Matching: Write the letter of the best match in the space before each name (11 points) A. Pioneer in biopsychology B. Chemical synapses H Fritch and Hitzig C. Neurons in tissue culture G Ramon y Cajal D. Nerve growth factor J Charles Scott Sherrington E. Gap junctions B Otto Loewi F. Induction of CNS development F Hans Spemann G. Prolific neuroanatomist, Golgi method K Bror Rexed H. Electrical stimulation of neocortex C Ross Harrison I. Pharmacological definitions A Karl Lashley J. Spinal reflexes, physiology L Walle Nauta K. Layers of the gray matter D Rita Levi-Montalcini L. Selective stains for degenerating axons N Hans Kuypers M. Tract tracing by MRI N. Descending pathways, motor control 2) Short definitions: (22 points) a) Anterograde degeneration When an axon is transected, the portion of the axon no longer connected to the cell body undergoes “anterograde” degeneration. [When neuronal cell bodies are destroyed, their axons undergo anterograde degeneration.] b) Motor neuron A neuron with an axon that leaves the CNS. It terminates on a muscle cell or on a peripheral ganglion. c) Schwann cell Glial cell found in peripheral nerves. Schwann cells form myelin in the PNS [by wrapping their membranes around axons]. 9.14, March 19, 2014 Page 1 9.14_2014 Midterm Exam NAME KEY Class 19 d) Sensory placode A thickening of a region of the ectodermal layer of the embryo in which some of the cells become primary sensory neurons. e) Rhombic lip A transient neural proliferative zone located in the alar plate of the rostral hindbrain.
    [Show full text]
  • CENTRAL NERVOUS SYSTEM Composed from Spinal Cord and Brain
    CENTRAL NERVOUS SYSTEM composed from spinal cord and brain SPINAL CORD − is developmentally the oldest part of CNS − is long about 45 cm in adult − fills upper 2/3 of vertebral canal cranial border at level of: foramen magnum, pyramidal decussation, exit of first pair of spinal nerves caudal border: level of L1 vertebra – medullary cone – filum terminale made by pia mater (ends at level of S2 vertebra) – spinal roots below L1 vertebra form cauda equina two enlargements: • cervical enlargement (CV – ThI): origin of nerves for upper extremity – brachial plexus • lumbosacral enlargement (LI – SII): origin of nerves for lower extremity – lumbosacral plexus Spinal segment is part of spinal cord where 1 pair of spinal n. exits. Spinal cord consists of 31 spinal segments and 31 pairs of spinal nn.: 8 cervical, 12 thoracic, 5 lumbar, 1 coccygeal. Spinal nn. leave spinal cord through íntervertebral foramens. Denticulate ligg. attach spinal segments to vertebral canal. Dermatome is part of skin innervated by 1 spinal nerve. external features: • anterior median fissure • anterolateral sulcus – exits of anterior roots of spinal nn. (laterally to anterior median fissure) • posterolateral sulcus – exits of 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) is divided by posterior intermediate sulcus to: − gracile fasciculus – medial one − cuneate fasciculus – lateral one, both for sensory tracts of fine sensation White matter of spinal cord contains fibres of ascending and descending nerve tracts.
    [Show full text]
  • Median Aperture of the Fourth Ventricle Revisited
    Folia Morphol. Vol. 70, No. 2, pp. 84–90 Copyright © 2011 Via Medica O R I G I N A L A R T I C L E ISSN 0015–5659 www.fm.viamedica.pl Median aperture of the fourth ventricle revisited M. Ciołkowski1, 2, M. Sharifi1, 3, S. Tarka4, B. Ciszek1, 5 1Department of Descriptive and Clinical Anatomy, Medical University of Warsaw, Poland 2Department of Neurosurgery, Bielanski Hospital, Warsaw, Poland 3Department of Paediatric Otolaryngology, Medical University of Warsaw, Poland 4Department of Forensic Medicine, Medical University of Warsaw, Poland 5Department of Neurosurgery, Prof. Bogdanowicz Children’s Hospital, Warsaw, Poland [Received 22 March 2011; Accepted 5 April 2011] Background: The median aperture of Magendie is the largest of three open- ings of the fourth ventricle and thus it forms the main path for the outflow of the cerebrospinal fluid from the ventricle. The Magendie aperture connects the fourth ventricle with the cisterna magna and makes a natural corridor for neu- rosurgical approach and inspection of the ventricle and its floor. The purpose of this study was to give a contemporary anatomical view of this structure in the context of historical data. Material and methods: The Magendie foramen was studied in 30 fixed spe- cimens of human brainstems with cerebella. The microdissection technique was used. Measurements were taken with a microscope ocular ruler. Results: The aperture is limited by the following structures: obex and gracile tubercles inferiorly, and tela choroidea with choroid plexus superolaterally. Obex tubercles usually have the form of a piece of neural tissue bridging two halves of the brainstem above the entrance to the central canal.
    [Show full text]
  • Meninges,Cerebrospinal Fluid, and the Spinal Cord
    The Nervous System MENINGES CSF Introduction Protection of the brain Bone (skull) Membranes (meninges) Watery cushion (cerebrospinal fluid) Blood-brain barrier (astrocytes) The Meninges Series of membranes Cover and protect the CNS Anchor and cushion the brain Contain cerebrospinal fluid (CSF) The Meninges Three layers Dura mater Arachnoid mater Pia mater Skin of scalp Periosteum Bone of skull Periosteal Dura Meningeal mater Superior Arachnoid mater sagittal sinus Pia mater Subdural Arachnoid villus space Blood vessel Subarachnoid Falx cerebri space (in longitudinal fissure only) Figure 12.24 The Meninges Dura mater Strongest meninx Fibrous connective tissue Limit excessive movement of the brain Superior sagittal sinus Falx cerebri Straight sinus Crista galli of the Tentorium ethmoid cerebelli bone Falx Pituitary cerebelli gland (a) Dural septa Figure 12.25a The Meninges Arachnoid mater Middle layer with weblike extensions Separated from the dura mater by the subdural space Subarachnoid space contains CSF and blood vessels The Meninges Pia mater Layer of delicate vascularized connective tissue Clings tightly to the brain Meningitis Inflammation of meninges May be bacterial or viral Diagnosed by obtaining CSF sample via lumbar tap T12 Ligamentum flavum L5 Lumbar puncture needle entering subarachnoid space L4 Supra- spinous ligament L5 Filum terminale S1 Inter- Cauda equina vertebral Arachnoid Dura in subarachnoid disc matter mater space Figure 12.30 Cerebrospinal Fluid (CSF) Composition Watery solution Modified
    [Show full text]
  • Chapter 14 Lecture Outline
    Chapter 14 Lecture Outline See separate PowerPoint slides for all figures and tables pre- inserted into PowerPoint without notes. Copyright © McGraw-Hill Education. Permission required for reproduction or display. 1 Introduction • Evolution of human central nervous system shows that spinal cord has changed very little, while brain has changed a great deal – Greatest growth in areas of vision, memory, and motor control of the prehensile hand 14-2 Major Landmarks • Three major portions of the brain – Cerebrum is 83% of brain volume; cerebral hemispheres, gyri and sulci, longitudinal fissure, corpus callosum – Cerebellum contains 50% of the neurons; second largest brain region, located in posterior cranial fossa – Brainstem is the portion of the brain that remains if the cerebrum and cerebellum are Figure 14.1b removed; diencephalon, midbrain, pons, and medulla oblongata 14-3 Major Landmarks Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Longitudinal fissure—deep Cerebral hemispheres groove that separates cerebral hemispheres • Gyri—thick folds Frontal lobe Central sulcus • Sulci—shallow grooves Parietal lobe • Corpus callosum—thick nerve bundle at bottom of Occipital lobe longitudinal fissure that Longitudinal fissure connects hemispheres (a) Superior view Figure 14.1a 14-4 Major Landmarks Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Central sulcus Parietal lobe Cingulate gyrus Corpus callosum Parieto–occipital sulcus Frontal lobe Occipital lobe
    [Show full text]