MINISTRY of HEALTH of UKRAINE Higher State Educational Establishment of Ukraine “Ukranian Medical Stomatological Academy”
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MINISTRY OF HEALTH OF UKRAINE Higher State Educational Establishment of Ukraine “Ukranian Medical Stomatological Academy” "Approved" at the meeting of the Department Human Anatomy on 29.08. 2019. Minutes № 1 Head of Department Professor O. O. Sherstiuk _____________________ METHODICAL GUIDANCE for students’ self-directed work at practical sessions (when preparing for and during practical sessions) Academic subject Human Anatomy Module №2 «Splanchnology. Central nervous system and sensory organs» Year of study I Faculty foreign students’ training faculty, specialty «Medicine» Poltava 2019 Ministry of Health of Ukraine Higher State Educational Establishment of Ukraine “Ukranian Medical Stomatological Academy” Department of Human Anatomy Composed by N.L. Svinthythka, Associate Professor at the Department of Human Anatomy, PhD in Medicine, Associate Professor V.H. Hryn, Associate Professor at the Department of Human Anatomy, PhD in Medicine, Associate Professor A.V. Pilugin, Associate Professor at the Department of Human Anatomy, PhD in Medicine, Associate Professor K.A. Lazarieva, Lecturer at the Department of Human Anatomy. Schedule of classes for students of foreign students’ Training faculty, specialty «Medicine» on module № 2 «Splanchnology. Central nervous system and sensory organs» № Topic Instru ction Нours 21 Internal structure of spinal cord. White and grey matters of the 2 spinal cord. 22 Medulla oblongata, pons. 2 23 Cerebellum. The isthmus of the rhombencephalon. 2 24 The fourth ventricle, the rhomboid fossa. 2 25 Midbrain. 2 26 Diencephalon, the third ventricle. 2 27 External structure of cerebral hemispheres. 2 28 The rhinencephalon. Limbic brain. The basal nuclei. 2 29 Structure of grey matter and cortex of cerebral hemispheres. 2 Functional arrangement of the cerebral cortex. 30 The lateral ventricles. The white matter of the cerebral 2 hemispheres. The meninges of the brain. Circulation of cerebrospinal liquid. 31 General esthesiology. Visual analyzer. Eyeball: layers, chambers, 2 refracting medias. 32 Accessory structures of visual analyzer. Nervous pathway of 2 visual analyzer. 33 General characteristic of organ for hearing. External and middle 2 ears. Bones of middle ear, tympanic cavity, its walls. Topic 21. Internal structure of spinal cord. White and grey matters of the spinal cord. 1. Relevance of the topic: In spinal cord injury complications arise that result in violations of sensitivity, motor activity. Knowledge of the structure of the spinal cord allows the patient to put a true topical diagnosis. 2. The specific aims: Explain the internal structure of the spinal cord. To explain: - Structure of the gray matter of the spinal cord; - The structure of the white matter of the spinal cord; - The nucleus of the spinal cord, their function. 3. Basic knowledge and skills necessary to study the topic (inter-disciplinary integration). Biology Knowing the structure of the To be able to distinguish between spinal cord of mammals gray and white matter of the spinal Histology Know the histological structure Tocord be able to distinguish between of gray and white matter gray and white matter of the spinal 4. The tasks for students' individual work. cord 4.1. The list of basic terms, parameters, characteristics which the student should master while preparing for the class. Canalis centralis The central channel Substantia grisea Grey matter Cornu anterius The front horn Cornu laterale Side horns Cornu posterius Rear horns Substantia alba White matter Substantia gelatinosa centralis Central gelatinous substance Columnae griseae Gray column Columna anterior The front pillar Columna posterior The rear pillar 4.2. Theoretical questions for the class: 1. Name the boundaries and show the spinal cord. 2. The name and display the external structure of the spinal cord. 3. What is spinal segment and that their number. 4. How many segments distinguish each of the spinal cord reflex What? 5. What are the components of the reflex arc. 6. What is represented mostly gray and white matter of the spinal cord? 7. What distinguished cord in the spinal cord? 8. What form the gray matter of the spinal cord and which parts of it are distinguished (in operechnomu cut)? 9. What are the core distinction within the gray matter of the spinal cord, and where are they? 10. As built spinal nerve? 11. Due to what formed the anterior and posterior roots of spinal nerves? 4.3. Practical tasks pertaining to the topic and to be completed during the class:The isolated preparation (cut the spinal cord) to be able to show gray, white matter, rear, front spine, spinal ganglion. The content of the topic: INTERNAL ORGANIZATION In transverse section, the spinal cord is incompletely divided into symmetrical halves by a dorsal (posterior) median septum and a ventral (anterior) median sulcus . It consists of an outer layer of white matter and an inner core of grey matter; their relative sizes and configuration vary according to level. The amount of grey matter reflects the number of neurones present; it is proportionately largest in the cervical and lumbar enlargements, which contain the neurones that innervate the limbs. The absolute amount of white matter is greatest at cervical levels, and decreases progressively at lower levels, because descending tracts shed fibres as they descend and ascending tracts accumulate fibres as they ascend. A diminutive central canal, lined by columnar, ciliated epithelium (ependyma) and containing cerebrospinal fluid (CSF), extends the whole length of the spinal cord lying in the centre of the spinal grey matter. Rostrally, the central canal extends into the caudal half of the medulla oblongata and then opens into the fourth ventricle. SPINAL GREY MATTER In three dimensions, the spinal grey matter is shaped like a fluted column .In transverse section the column is often described as being ‘butterfly-shaped’ or resembling the letter ‘H’ .It consists of four linked cellular masses, the right and left dorsal and ventral horns, that project dorsolaterally and ventrolaterally towards the surface respectively. The grey matter that immediately surrounds the central canal and unites the two sides constitutes the dorsal and ventral grey commissures. The dorsal horn is the site of termination of the primary afferent fibres that enter the cord via the dorsal roots of spinal nerves. The tip of the dorsal horn is separated from the dorsolateral surface of the cord by a thin fasciculus or tract (of Lissauer) in which primary afferent fibres ascend and descend for a short distance before terminating in the subjacent grey matter. The ventral horn contains efferent neurones whose axons leave the spinal cord in ventral nerve roots. A small intermediate, or lateral, horn is present at thoracic and upper lumbar levels; it contains the cell bodies of preganglionic sympathetic neurones. Spinal grey matter is a complex mixture of neuronal cell bodies, their processes and synaptic connections, neuroglia and blood vessels. Neurones in the grey matter are multipolar. They vary in size and features such as the length and the arrangement of their axons and dendrites. Neurones may be intrasegmental, i.e. contained within a single segment, or intersegmental, i.e. their ramifications spread through several segments. Neuronal cell groups of the spinal cord Viewed from the perspective of its longitudinal columnar organization, the grey matter of the spinal cord consists of a series of discontinuous cell groupings associated with their corresponding segmentally arranged spinal nerves. At any particular cross-sectional level these cell groupings are often considered to correspond approximately with one or more of ten cell layers, known as Rexed's laminae. These laminae are defined on the basis of neuronal size, shape, cytological features and density and are numbered in a dorsoventral sequence. Laminae I–IV correspond to the dorsal part of the dorsal horn, and are the main site of termination of cutaneous primary afferent terminals and their collaterals. Many complex polysynaptic reflex paths (ipsilateral, contralateral, intrasegmental and intersegmental) start from this region, as also do many long ascending tract fibres which pass to higher levels. Lamina I (lamina marginalis) is a very thin layer with an ill- defined boundary at the dorsolateral tip of the dorsal horn. It has a reticular appearance, reflecting its content of intermingling bundles of coarse and fine nerve fibres. It contains small, intermediate and large neuronal somata, many of which are fusiform in shape. The much larger lamina II consists of densely packed small neurones, responsible for its dark appearance in Nissl-stained sections. With myelin stains, lamina II is characteristically distinguished from adjacent laminae by the almost total lack of myelinated fibres. Lamina II corresponds to the substantia gelatinosa. Lamina III consists of somata which are mostly larger, more variable and less closely packed than those in lamina II. It also contains many myelinated fibres. Some workers consider that the substantia gelatinosa contains part or all of lamina III as well as lamina II. The ill- defined nucleus proprius of the dorsal horn corresponds to some of the cell constituents of laminae III and IV. Lamina IV is a thick, loosely packed, heterogeneous zone permeated by fibres. Its neuronal somata vary considerably in size and shape, from small and round, through intermediate and triangular, to very large and stellate. Laminae V and VI lie at the base of the dorsal horn. They receive most of the terminals of proprioceptive primary afferents, profuse corticospinal projections from the motor and sensory cortex and input from subcortical levels, suggesting their involvement in the regulation of movement. Lamina V is a thick layer, divisible into a lateral third and medial two-thirds. Both have a mixed cell population but the former contains many prominent well-staining somata interlaced by numerous bundles of transverse, dorsoventral and longitudinal fibres. Lamina VI is most prominent in the limb enlargements. It has a densely staining medial third of small, densely packed neurones and a lateral two-thirds containing larger, more loosely packed, triangular or stellate somata.