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Distance Learning Program Anatomy of the Human Brain/Sheep Brain Dissection
Distance Learning Program Anatomy of the Human Brain/Sheep Brain Dissection This guide is for middle and high school students participating in AIMS Anatomy of the Human Brain and Sheep Brain Dissections. Programs will be presented by an AIMS Anatomy Specialist. In this activity students will become more familiar with the anatomical structures of the human brain by observing, studying, and examining human specimens. The primary focus is on the anatomy, function, and pathology. Those students participating in Sheep Brain Dissections will have the opportunity to dissect and compare anatomical structures. At the end of this document, you will find anatomical diagrams, vocabulary review, and pre/post tests for your students. The following topics will be covered: 1. The neurons and supporting cells of the nervous system 2. Organization of the nervous system (the central and peripheral nervous systems) 4. Protective coverings of the brain 5. Brain Anatomy, including cerebral hemispheres, cerebellum and brain stem 6. Spinal Cord Anatomy 7. Cranial and spinal nerves Objectives: The student will be able to: 1. Define the selected terms associated with the human brain and spinal cord; 2. Identify the protective structures of the brain; 3. Identify the four lobes of the brain; 4. Explain the correlation between brain surface area, structure and brain function. 5. Discuss common neurological disorders and treatments. 6. Describe the effects of drug and alcohol on the brain. 7. Correctly label a diagram of the human brain National Science Education -
The Nerve Lesion in the Carpal Tunnel Syndrome
J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.39.7.615 on 1 July 1976. Downloaded from Journal of Neurology, Neurosurgery, and Psychiatry, 1976, 39, 615-626 The nerve lesion in the carpal tunnel syndrome SYDNEY SUNDERLAND From the Department of Experimental Neurology, University of Melbourne, Parkville, Victoria, Australia SYNOPSIS The relative roles of pressure deformation and ischaemia in the production of compres- sion nerve lesions remain a controversial issue. This paper concerns the genesis of the structural changes which follow compression of the median nerve in the carpal tunnel. The initial lesion is an intrafunicular anoxia caused by obstruction to the venous return from the funiculi as the result of increased pressure in the tunnel. This leads to intrafunicular oedema and an increase in intrafunicular pressure which imperil and finally destroy nerve fibres by impairing their blood supply and by compression. The final outcome is the fibrous tissue replacement of the contents of the funiculi. Protected by copyright. In 1862 Waller described the motor, vasomotor, (Gasser, 1935; Allen, 1938; Bentley and Schlapp, and sensory changes which followed the com- 1943; Richards, 1951; Moldaver, 1954; Gelfan pression of nerves in his own arm. His account and Tarlov, 1956). carried no reference to the mechanism In the 1940s Weiss and his associates (Weiss, responsible for blocking conduction in the nerve 1943, 1944; Weiss and Davis, 1943; Weiss and fibres, presumably because he regarded it as Hiscoe, 1948), who were primarily concerned obvious that pressure was the offending agent. with the technical problem of uniting severed Interest in the effects of nerve compression nerves, observed that a divided nerve enclosed was not renewed until the 1920s when cuff or in a tightly fitting arterial sleeve became swollen tourniquet compression was used to produce a proximal and distal to the constriction. -
The Strain Rates in the Brain, Brainstem, Dura, and Skull Under Dynamic Loadings
Mathematical and Computational Applications Article The Strain Rates in the Brain, Brainstem, Dura, and Skull under Dynamic Loadings Mohammad Hosseini-Farid 1,2,* , MaryamSadat Amiri-Tehrani-Zadeh 3, Mohammadreza Ramzanpour 1, Mariusz Ziejewski 1 and Ghodrat Karami 1 1 Department of Mechanical Engineering, North Dakota State University, Fargo, ND 58104, USA; [email protected] (M.R.); [email protected] (M.Z.); [email protected] (G.K.) 2 Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN 55905, USA 3 Department of Computer Science, North Dakota State University, Fargo, ND 58104, USA; [email protected] * Correspondence: [email protected]; Tel.: +1-7012315859 Received: 7 March 2020; Accepted: 5 April 2020; Published: 7 April 2020 Abstract: Knowing the precise material properties of intracranial head organs is crucial for studying the biomechanics of head injury. It has been shown that these biological tissues are significantly rate-dependent; hence, their material properties should be determined with respect to the range of deformation rate they experience. In this paper, a validated finite element human head model is used to investigate the biomechanics of the head in impact and blast, leading to traumatic brain injuries (TBI). We simulate the head under various directions and velocities of impacts, as well as helmeted and unhelmeted head under blast shock waves. It is demonstrated that the strain rates for the brain 1 are in the range of 36 to 241 s− , approximately 1.9 and 0.86 times the resulting head acceleration under impacts and blast scenarios, respectively. The skull was found to experience a rate in the range 1 of 14 to 182 s− , approximately 0.7 and 0.43 times the head acceleration corresponding to impact and blast cases. -
Nervous Tissue
Nervous Tissue • Controls and integrates all body activities within limits that maintain life • Three basic functions – sensing changes with sensory receptors • fullness of stomach or sun on your face – interpreting and remembering those changes – reacting to those changes with effectors • muscular contractions • glandular secretions Major Structures of the Nervous System • Brain, cranial nerves, spinal cord, spinal nerves, ganglia, enteric plexuses and sensory receptors Organization of the Nervous System • CNS is brain and spinal cord • PNS is everything else Nervous System Divisions • Central nervous system (CNS) – consists of the brain and spinal cord • Peripheral nervous system (PNS) – consists of cranial and spinal nerves that contain both sensory and motor fibers – connects CNS to muscles, glands & all sensory receptors Subdivisions of the PNS • Somatic (voluntary) nervous system (SNS) – neurons from cutaneous and special sensory receptors to the CNS – motor neurons to skeletal muscle tissue • Autonomic (involuntary) nervous systems – sensory neurons from visceral organs to CNS – motor neurons to smooth & cardiac muscle and glands • sympathetic division (speeds up heart rate) • parasympathetic division (slow down heart rate) • Enteric nervous system (ENS) – involuntary sensory & motor neurons control GI tract – neurons function independently of ANS & CNS Neurons • Functional unit of nervous system • Have capacity to produce action potentials – electrical excitability • Cell body – single nucleus with prominent nucleolus – Nissl -
Deconstructing Spinal Interneurons, One Cell Type at a Time Mariano Ignacio Gabitto
Deconstructing spinal interneurons, one cell type at a time Mariano Ignacio Gabitto Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy under the Executive Committee of the Graduate School of Arts and Sciences COLUMBIA UNIVERSITY 2016 © 2016 Mariano Ignacio Gabitto All rights reserved ABSTRACT Deconstructing spinal interneurons, one cell type at a time Mariano Ignacio Gabitto Abstract Documenting the extent of cellular diversity is a critical step in defining the functional organization of the nervous system. In this context, we sought to develop statistical methods capable of revealing underlying cellular diversity given incomplete data sampling - a common problem in biological systems, where complete descriptions of cellular characteristics are rarely available. We devised a sparse Bayesian framework that infers cell type diversity from partial or incomplete transcription factor expression data. This framework appropriately handles estimation uncertainty, can incorporate multiple cellular characteristics, and can be used to optimize experimental design. We applied this framework to characterize a cardinal inhibitory population in the spinal cord. Animals generate movement by engaging spinal circuits that direct precise sequences of muscle contraction, but the identity and organizational logic of local interneurons that lie at the core of these circuits remain unresolved. By using our Sparse Bayesian approach, we showed that V1 interneurons, a major inhibitory population that controls motor output, fractionate into diverse subsets on the basis of the expression of nineteen transcription factors. Transcriptionally defined subsets exhibit highly structured spatial distributions with mediolateral and dorsoventral positional biases. These distinctions in settling position are largely predictive of patterns of input from sensory and motor neurons, arguing that settling position is a determinant of inhibitory microcircuit organization. -
The Nervous System
The Nervous System • A network of billions of nerve cells linked together in a highly organized fashion to form the rapid control center of the body. • Functions include: – Integrating center for homeostasis, movement, and almost all other body functions. – The mysterious source of those traits that we think of as setting humans apart from animals Basic Functions of the Nervous System 1. Sensation • Monitors changes/events occurring in and outside the body. Such changes are known as stimuli and the cells that monitor them are receptors. 2. Integration • The parallel processing and interpretation of sensory information to determine the appropriate response 3. Reaction • Motor output. – The activation of muscles or glands (typically via the release of neurotransmitters (NTs)) Organization of the Nervous System • 2 big initial divisions: 1. Central Nervous System • The brain + the spinal cord – The center of integration and control 2. Peripheral Nervous System • The nervous system outside of the brain and spinal cord • Consists of: – 31 Spinal nerves » Carry info to and from the spinal cord – 12 Cranial nerves » Carry info to and from the brain Peripheral Nervous System • Responsible for communication btwn the CNS and the rest of the body. • Can be divided into: – Sensory Division • Afferent division – Conducts impulses from receptors to the CNS – Informs the CNS of the state of the body interior and exterior – Sensory nerve fibers can be somatic (from skin, skeletal muscles or joints) or visceral (from organs w/i the ventral body cavity) – Motor Division • Efferent division – Conducts impulses from CNS to effectors (muscles/glands) – Motor nerve fibers Motor Efferent Division • Can be divided further: – Somatic nervous system • VOLUNTARY (generally) • Somatic nerve fibers that conduct impulses from the CNS to skeletal muscles – Autonomic nervous system • INVOLUNTARY (generally) • Conducts impulses from the CNS to smooth muscle, cardiac muscle, and glands. -
Meninges,Cerebrospinal Fluid, and the Spinal Cord
The Nervous System SPINAL CORD Spinal Cord Continuation of CNS inferior to foramen magnum (medulla) Simpler Conducts impulses to and from brain Two way conduction pathway Reflex actions Spinal Cord Passes through vertebral canal Foramen magnum L2 Conus medullaris Filum terminale Cauda equina Cervical Cervical spinal nerves enlargement Dura and arachnoid Thoracic mater spinal nerves Lumbar enlargement Conus medullaris Lumbar Cauda spinal nerves equina Filum (a) The spinal cord and its nerve terminale Sacral roots, with the bony vertebral spinal nerves arches removed. The dura mater and arachnoid mater are cut open and reflected laterally. Figure 12.29a Spinal Cord Spinal nerves 31 pairs Cervical and lumbar enlargements The nerves serving the upper and lower limbs emerge here Cervical Cervical spinal nerves enlargement Dura and arachnoid Thoracic mater spinal nerves Lumbar enlargement Conus medullaris Lumbar Cauda spinal nerves equina Filum (a) The spinal cord and its nerve terminale Sacral roots, with the bony vertebral spinal nerves arches removed. The dura mater and arachnoid mater are cut open and reflected laterally. Figure 12.29a Spinal Cord Protection Bone, meninges, and CSF Spinal tap-inferior to second lumbar vertebra 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 Spinal Cord Cross section Central gray matter Cortex of white matter Epidural -
Spinal Cord Organization
Lecture 4 Spinal Cord Organization The spinal cord . Afferent tract • connects with spinal nerves, through afferent BRAIN neuron & efferent axons in spinal roots; reflex receptor interneuron • communicates with the brain, by means of cell ascending and descending pathways that body form tracts in spinal white matter; and white matter muscle • gives rise to spinal reflexes, pre-determined gray matter Efferent neuron by interneuronal circuits. Spinal Cord Section Gross anatomy of the spinal cord: The spinal cord is a cylinder of CNS. The spinal cord exhibits subtle cervical and lumbar (lumbosacral) enlargements produced by extra neurons in segments that innervate limbs. The region of spinal cord caudal to the lumbar enlargement is conus medullaris. Caudal to this, a terminal filament of (nonfunctional) glial tissue extends into the tail. terminal filament lumbar enlargement conus medullaris cervical enlargement A spinal cord segment = a portion of spinal cord that spinal ganglion gives rise to a pair (right & left) of spinal nerves. Each spinal dorsal nerve is attached to the spinal cord by means of dorsal and spinal ventral roots composed of rootlets. Spinal segments, spinal root (rootlets) nerve roots, and spinal nerves are all identified numerically by th region, e.g., 6 cervical (C6) spinal segment. ventral Sacral and caudal spinal roots (surrounding the conus root medullaris and terminal filament and streaming caudally to (rootlets) reach corresponding intervertebral foramina) collectively constitute the cauda equina. Both the spinal cord (CNS) and spinal roots (PNS) are enveloped by meninges within the vertebral canal. Spinal nerves (which are formed in intervertebral foramina) are covered by connective tissue (epineurium, perineurium, & endoneurium) rather than meninges. -
Major Motor & Sensory Projections
Major Motor & Sensory Projections Neuroanatomy > Brainstem > Brainstem MAJOR MOTOR & SENSORY PROJECTIONS  FULL TEXT OVERVIEW • Here, we will learn a consolidated view of the major descending (motor) and ascending (sensory) pathways from the cerebrum through the brainstem into the spinal cord. • Start a table, specify that we will learn about the following major pathway projections: Motor • Corticospinal tract (CST) • Corticobulbar (aka corticonuclear) tract Sensory • Posterior column/medial lemniscus • Anterolateral system (spinothalamic) tract • Trigeminothalamic tract MOTOR PATHWAYS Anatomical Structures Begin with the motor pathways. • Label the superior/inferior axes. • Draw a coronal view of the right brain. • Then, the brainstem. • The upper cervical spinal cord. 1 / 5 • And the lumbar cord. Innervation • Start another table. Write that for the motor fibers: • The corticospinal tract fibers innervate the body via spinal motor neurons. - Specify that the lateral CST innervates distal musculature for fine motor movements - Whereas the anterior CST innervates proximal musculature for gross motor movements. • The corticobulbar fibers (aka corticonuclear fibers) innervate the face via the CNs. Projections • Now, demarcate the internal capsule deep within the cerebrum – the motor fibers consolidate here before entering the ipsilateral cerebral peduncle in the midbrain. • Next, draw the twisting descent of each fiber group through the subcortical white matter. • Show that the facial fibers [RED] emerge from the lateral convexity, descend medially and, generally, decussate to synapse on different cranial nerve nuclei throughout their descent. • Then, show that the leg fibers [GREEN] emerge paracentrally, descend laterally through the brainstem into the ipsilateral medullary pyramid. • Show that the arm fibers [BLUE] emerge from the upper convexity, descend in between the facial and leg fibers, medial to the leg fibers through the brainstem into the ipsilateral medullary pyramid. -
Nerve and Nerve Injuries” Sunderland : 50 Years Later
2019 Nerve and Nerve Injuries” Sunderland : 50 years later Faye Chiou Tan, MD Professor, Dir. EDX, H. Ben Taub PMR, Baylor College of Medicine Chief PMR, Dir. EDX, Harris Health System 2019 Financial Disclosure • Elsevier Book Royalties for “EMG Secrets” textbook • Revance, consultation panel 2019 Warning Videotaping or taking pictures of the slides associated with this presentation is prohibited. The information on the slides is copyrighted and cannot be used without permission and author attribution. Introduction – Sydney Sunderland was Professor of Experimental Neurology at the University of Melbourne. – His textbook “Nerve and Nerve lnjuries” published in 1968 is no longer in print (copies $1000 on the internet) – Here is a review as relates to new technology: Ultrahigh frequency musculoskeletal ultrasound Part I – I. Anatomic and physiologic features of A. Peripheral nerve fibers B. Peripheral nerve trunks I.A. Peripheral nerve fibers – Axoplasm – Increased flow of cytoplasm from cell body into axons during electrical stimulation (Grande and Richter 1950) – Although overall proximal to distal axoplasmic flow, the pattern of streaming in the axon is bidirectional and faster (up to 3-7 cm/day) (Lubinska 1964). I. A. Peripheral nerve fibers – Sheath – Myelinated – Length of internode elongates with growth (Vizoso and Young 1948, Siminoff 1965) – In contrast, remyelination in adults produce short internodes of same length (Leegarrd 1880, Young 1945,…) – Incisures of Schmidt-Lantermann are clefts conical clefts that open when a nerve trunk is stretched thereby preventing distortion of myelin. (Glees, 1943) Schmidt-Lantermann Clefts Sunderland S. Nerve and Nerve Injuries, Sunderland, Livingstone,LTD, Edinburgh/London, 1968, p. 8 I. A. -
Review of Spinal Cord Basics of Neuroanatomy Brain Meninges
Review of Spinal Cord with Basics of Neuroanatomy Brain Meninges Prof. D.H. Pauža Parts of Nervous System Review of Spinal Cord with Basics of Neuroanatomy Brain Meninges Prof. D.H. Pauža Neurons and Neuroglia Neuron Human brain contains per 1011-12 (trillions) neurons Body (soma) Perikaryon Nissl substance or Tigroid Dendrites Axon Myelin Terminals Synapses Neuronal types Unipolar, pseudounipolar, bipolar, multipolar Afferent (sensory, centripetal) Efferent (motor, centrifugal, effector) Associate (interneurons) Synapse Presynaptic membrane Postsynaptic membrane, receptors Synaptic cleft Synaptic vesicles, neuromediator Mitochondria In human brain – neurons 1011 (100 trillions) Synapses – 1015 (quadrillions) Neuromediators •Acetylcholine •Noradrenaline •Serotonin •GABA •Endorphin •Encephalin •P substance •Neuronal nitric oxide Adrenergic nerve ending. There are many 50-nm-diameter vesicles (arrow) with dark, electron-dense cores containing norepinephrine. x40,000. Cell Types of Neuroglia Astrocytes - Oligodendrocytes – Ependimocytes - Microglia Astrocytes – a part of hemoencephalic barrier Oligodendrocytes Ependimocytes and microglial cells Microglia represent the endogenous brain defense and immune system, which is responsible for CNS protection against various types of pathogenic factors. After invading the CNS, microglial precursors disseminate relatively homogeneously throughout the neural tissue and acquire a specific phenotype, which clearly distinguish them from their precursors, the blood-derived monocytes. The ´resting´ microglia -
Nervous Tissue
Nervous Tissue • Controls and integrates all body activities within limits that maintain life • Three basic functions – sensing changes with sensory receptors • fullness of stomach or sun on your face – interpreting and remembering those changes – reacting to those changes with effectors • muscular contractions • glandular secretions 12-1 Major Structures of the Nervous System • Brain, cranial nerves, spinal cord, spinal nerves, ganglia, enteric plexuses and sensory receptors 12-2 Organization of the Nervous System • CNS is brain and spinal cord • PNS is everything else 12-3 Nervous System Divisions • Central nervous system (CNS) – consists of the brain and spinal cord • Peripheral nervous system (PNS) – consists of cranial and spinal nerves that contain both sensory and motor fibers – connects CNS to muscles, glands & all sensory receptors 12-4 Subdivisions of the PNS • Somatic (voluntary) nervous system (SNS) – neurons from cutaneous and special sensory receptors to the CNS – motor neurons to skeletal muscle tissue • Autonomic (involuntary) nervous systems – sensory neurons from visceral organs to CNS – motor neurons to smooth & cardiac muscle and glands • sympathetic division (speeds up heart rate) • parasympathetic division (slow down heart rate) • Enteric nervous system (ENS) – involuntary sensory & motor neurons control GI tract – neurons function independently of ANS & CNS 12-5 Neurons • Functional unit of nervous system • Have capacity to produce action potentials – electrical excitability • Cell body • Cell processes = dendrites