DOCSLIB.ORG

Nervous System Disorders Structure and Function of the Nervous System Chap

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Nervous System Disorders Structure and Function of the Nervous System Chap Bio217 F2014 Unit 4 Bio217: Pathophysiology Class Notes Professor Linda Falkow Unit IV: Nervous System Disorders Structure and Function of the Nervous System Chap. 12: Structure & Function of the Nervous System Chapter 12 Chap. 13: Pain, Temperature, Sleep, and Sensory Chap. 14: Alterations in Cognitive Systems, Cerebral Dynamics, and Motor Function Chap. 15: Disorders of the Central and Peripheral Nervous Systems Overview of the Nervous System Overview of the Nervous System • Peripheral nervous system (PNS) • Central nervous system (_____) – Somatic nervous system – ____________ • Motor (efferent) and sensory (afferent) • Peripheral nervous system (_____) pathways regulating voluntary motor control of skeletal muscle – Cranial nerves – Autonomic nervous system (ANS) – Spinal nerves • Motor and sensory pathways regulating – Pathways body’s internal environment through • Afferent (__________) involuntary control of organ systems • Efferent (__________) – Sympathetic (“_____________”) – Parasympathetic (“Rest and repose”) Cells of the Nervous System Neuron • Neuron (conducts nerve impulses) • Axons – Variable size and structure – Myelin • Three components • Insulating layer of lipid material – Cell body (soma) • Formed by the Schwann cell • Nuclei = cell bodies in CNS – Endoneurium • Ganglia = cell bodies in PNS are ganglia • Delicate layer of CT around each axon – Dendrites – Neurilemma • __________ impulses • Thin membrane between myelin sheath and endoneurium – Axons • Carry impulses ________ from cell body 1 Bio217 F2014 Unit 4 Neuron Structural Classification of Neurons • Axons –Nodes of Ranvier • Based on number of processes • Regular interruptions of the myelin extending from cell body sheath –Unipolar – –Saltatory conduction Bipolar • Flow of ions between segments of –Multipolar myelin rather than along entire length of axon Functional Classification of Neurons Neurons • Sensory (afferent) – Transmit impulses from sensory receptors to CNS • Associational (interneurons) – Transmit impulses from neuron to neuron • Motor (efferent) – Transmit impulses from CNS to an effector Neuroglia Neuroglia • “Nerve glue” • Support the neurons of the CNS – Astrocytes – Oligodendroglia (oligodendrocytes) – Microglia – Ependemal A – astrocyte B – oligodendrocyte C – microglia D - ependymal 2 Bio217 F2014 Unit 4 Nerve Impulse Synapses • Region between adjacent neurons (pre- and • Neurons generate action potentials by postsynaptic neurons) is called a synapse selectively changing the electrical portion • Impulses are transmitted across synapse by of their plasma membranes and chemical and electrical conduction influencing other nearby neurons by release of neurotransmitters (chemicals) • Neurotransmitters – More than 30 substances • (ACh, serotonin, NE, dopamine) – Excitatory or Inhibitory Forebrain: Cerebrum Central Nervous System Gyri, sulci, and fissures Gray matter and white matter BRAIN: Cerebral nuclei (basal ganglia) • Forebrain – Cerebral hemispheres • Midbrain – Corpora quadrigemina, substantia nigra, and cerebral peduncles • Hindbrain – Cerebellum, pons, and medulla Forebrain Central Nervous System - functional areas • Diencephalon – Thalamus – Hypothalamus • Midbrain – Corpora quadrigemina • Superior and inferior colliculi – Tegmentum • Red nucleus and substantia nigra ( dopamine NE) • Cerebral peduncles 3 Bio217 F2014 Unit 4 Central Nervous System Spinal Cord • ____________ • Located in vertebral canal, protected – Cerebellum by vertebral column – Connects the brain and the body – Pons – Conducts somatic and autonomic reflexes – Medulla oblongata – Modulates sensory and motor function Spinal Cord Spinal Cord Reflex Arc Neuromuscular Junction • Receptor • Afferent (sensory) neuron • Efferent neuron • Effector 4 Bio217 F2014 Unit 4 Protective Structures Meninges • Cranium – Eight bones • Frontal, Occipital, Temporal (2), Parietal (2), Sphenoid, Ethmoid – Galea aponeurotica • Meninges – Protective membranes surrounding brain & SC • Dura mater • Arachnoid • Pia mater Protective Structures Protective Structures • Cerebrospinal fluid (CSF) • Vertebral column – Clear, colorless fluid similar to blood plasma and interstitial fluid – 33 vertebrae • 7 cervical, 12 thoracic, 5 lumbar, – 125 to 150 mL 5 fused sacral, 4 fused coccygeal – Produced by _____________ in lateral, third, and – Intervertebral disks fourth ventricles • Annulus fibrosus – Reabsorbed through _______________ • Nucleus pulposus Vertebral Column Blood Supply to the Brain • 800 to 1000 mL per minute • CO2 is the primary regulator for CNS blood flow • Internal carotid and vertebral arteries • Arterial circle (circle of Willis) 5 Bio217 F2014 Unit 4 Blood Supply to the Brain Blood Supply to the Brain Peripheral Nervous System Cranial Nerves • 31 pairs of spinal nerves – Named for vertebral level from which they exit – Mixed nerves – Arise from gray matter of the spinal cord • 12 pairs of cranial nerves – Sensory, motor, and mixed Spinal Nerves Autonomic Nervous System • Located in both the CNS and PNS • Maintains a homeostasis in visceral (internal) organs • Neurons – Preganglionic (myelinated) – Postganglionic (unmyelinated) 6 Bio217 F2014 Unit 4 Autonomic Nervous System Sympathetic Nervous System • Two divisions – Sympathetic • “Fight or flight” response • Thoracolumbar • Sympathetic (paravertebral) ganglia – Parasympathetic • “Rest or repose” response • Craniosacral • Preganglionic neurons travel to ganglia close to organs they innervate Neurotransmitters and Parasympathetic Nervous System Neuroreceptors of the ANS • SNS preganglionic fibers – ACh (_____________) • SNS postganglionic fibers – NE (_______________) • PSN preganglionic & postganglionic fibers – ACh Neurotransmitters and Aging and the Nervous System Neuroreceptors of the ANS • Decrease in the number of neurons – Decreased brain weight and size • Senile plaques • Neurofibrillary tangles • Slowing of neurologic responses 7 Bio217 F2014 Unit 4 Concept Check: • 1. One function of somatic NS that is not performed • 3. Which of the following best describes the SC? by the ANS is conduction of impulses: – A. Descends inferior to the lumbar vertebrae – A. To involuntary muscles and glands – B. Conducts motor impulses from the brain – B. To the CNS – C. To skeletal muscles – C. Descends to L4 – D. Between the brain and SC – D. Conducts sensory impulses to the brain • 2. Neurons are specialized for the conduction of impulses, while neuroglia: • 4. Which is not a protective covering of the CNS? – A. Support nerve tissue – A. Cauda equina – B. Serve as motor end plates – B. Dura mater – C. Synthesize ACh and AChE – C. Arachnoid – D. All of the above – D. Cranial bone • 5. The SNS: – A. Mobilizes E in times of need – B. Is innervated by cell bodies from T1 L2 – C. Is innervated by cell bodies located in the Pain, Temperature, Sleep, and cranial nerve nuclei – D. Both A and B are correct Sensory Function • 6. The PSN : Chapter 13 – A. Conserves and stores E – B. Has relatively short postganglionic neurons – C. Both A and B are correct – D. Has paravertebral ganglia Pain Neuroanatomy of Pain • “Pain is whatever the experiencing • Nociception person says it is, existing whenever he – Perception of pain says it does” —McCaffrey • Nociceptors – Free nerve endings in skin, muscle, joints, arteries, and the viscera that respond to chemical, mechanical, and thermal stimuli 8 Bio217 F2014 Unit 4 Pathways of Nociception Neuromodulation of Pain - Spinothalamic tracts • Neuromodulators – Located in pathways of NS – Triggered by tissue injury and or inflammation – Excitatory neuromodulation • Substance P, glutamate, somatostatin – Inhibitory neuromodulation • GABA, glycine, serotonin, NE, endorphins Neuromodulation of Pain Endorphin Response • Endorphins (endogenous morphines) – Neuropeptides – inhibit pain transmission in CNS – Bind opioid receptors • Beta-endorphins (rel. from hypothalamus & pit. gland) • Enkephalin (weaker than other endorphins) • Dynorphins (can stimulate pain) • Endomorphins (cause VD due to NO2 released from endothelial cells) Acute Pain Acute Pain • Referred pain – Pain present in an area removed or distant • Manifestations from point of origin – Fear and anxiety – Area of referred pain is supplied by same • Tachycardia, hypertension, fever, spinal segment as the actual site diaphoresis, dilated pupils, outward • Myocardial pain behaviors, elevated BG, infarction pain decreased gastric acid secretion and intestinal motility, and a general decrease in blood flow 9 Bio217 F2014 Unit 4 Chronic Pain Neuropathic Pain • May be sudden or develop insidiously • Result of trauma or disease of nerves • Usually defined as lasting at least 3 to 6 months • Peripheral • Produces significant behavior and psychologic changes – Painful diabetic neuropathy • Types: • Central – Low back pain – Phantom limb – Myofascial pain syndromes – Chronic postoperative pain – Cancer pain Temperature Regulation Heat Loss • Peripheral & central thermoreceptors • Hypothalamic control (range ~37o + 0.7o) • Radiation, Conduction, Convection • Vasodilation • Heat production • Decreased muscle tone – Metabolism • Evaporation – Skeletal muscle contraction • Increased respirations – Chemical thermogenesis • Voluntary measures • Heat conservation • Adaptation to warmer climates – Vasoconstriction – Voluntary mechanisms Temperature Regulation Fever • Resetting of the hypothalamic thermostat • Aging – Slow blood circulation, vasoconstrictive response, and metabolic rate • Activate heat production and conservation – Decreased sweating and perception
Load more

Recommended publications
  • A Cyclops and a Synotus by K
    J Neurol Psychopathol: first published as 10.1136/jnnp.s1-17.65.48 on 1 July 1936. Downloaded from 48 ORIGINAL PAPERS A CYCLOPS AND A SYNOTUS BY K. H. BOUMAN, AMSTERDAM, AND V. W. D. SCHENK, TiH HAGUE INTRODUCTION ONLY a small number of cases of cyclopia in human beings and mammals have been minutely examined. The number becomes still smaller if a more or less complete microscopic investigation of the central nervous system is stipulated. It is really only the cases of Davidson Black and Winkler and perhaps that of Naegli which answer this requirement. In contrast therewith there is an abundance of experimental studies in this field in urodela and other lower classes of animals. For all that, unanimity does not by any means prevail here, although the Protected by copyright. views of Stockard and his followers-who held that the first determination of the eye lay unpaired in the median line-and those of Spemann-who pointed to a paired rudiment from the outset, which views were originally diametrically opposed-appear to have drawn somewhat nearer to each other in recent years. Woerdeman, for instance, found that the paired rudiment of the eye shifts its position laterally downwards very early (when the folds of the medullary plate become visible) and he rightly says that this is not the same as Stockard's lateral growth of an unpaired eye rudiment. Yet, by saying this, he admits certain changes and growth conditions to which Fischel, for instance, did not do full justice. E. Manchot, on the other hand, who defends Stockard's views, admits that between the two regions of the eye http://jnnp.bmj.com/ rudiment there must be a tract of brain tissue (lamina terminalis and regio chiasmatica).
    [Show full text]
  • Hamburger Hamilton Stages
    UNSW Embryology- Chicken Development Stages http://embryology.med.unsw.edu.au/OtherEmb/chick1.htm Hamburger Hamilton Stages Hamburger Identification of Hamilton Age Stages Stages Before Laying Shell membrane of 3.5-4.5 Early egg formed in hr cleavage isthmus of oviduct Germ wall formed During from marginal cleavage periblast 4.5-24.0 Shell of egg Late cleavage hr formed in uterus After Laying Preprimitive streak 1 (embryonic shield) Initial primitive 2 6-7 hr streak, 0.3-0.5 mm long Intermediate 12-13 hr 3 primitive streak Definitive primitive 4 18-19 hr streak, ±1.88 mm long Head process 19-22 hr 5 (notochord) 6 23-25 hr Head fold 1 somite; neural 23-26 hr 7 folds ca. 1-3 somites; 7 to 8- 23-26 hr coelom 1 / 5 2007/03/20 9:05 UNSW Embryology- Chicken Development Stages http://embryology.med.unsw.edu.au/OtherEmb/chick1.htm 4 somites; blood 26-29 hr 8 islands 7 somites; primary 29-33 hr 9 optic vesicles 8-9 somites; 9+ to 10- ca. 33 hr anterior amniotic fold 10 somites; 3 10 33-38 hr primary brain vesicles 13 somites; 5 11 40-45 hr neuromeres of hindbrain 16 somites; 45-49 hr 12 telencephalon 19 somites; 13 48-52 hr atrioventricular canal ca. 20-21 somites; tail 13+ to 14- 50-52 hr bud 22 somites; trunk flexure; visceral 50-53 hr 14 arches I and II, clefts 1 and 2 23 somites; ca. premandibular 14+ to 15- 50-54 hr head cavities 24-27 somites; 15 50-55 hr visceral arch III, cleft 3 26-28 somites; 16 51-56 hr wing bud; posterior 2 / 5 2007/03/20 9:05 UNSW Embryology- Chicken Development Stages http://embryology.med.unsw.edu.au/OtherEmb/chick1.htm
    [Show full text]
  • Nervous System Cns
    THE NERVOUS SYSTEM CNS • Function The Spinal Cord • General Structure • Enclosed In: • Neural Foramen – length • Connects With: • Foramen magnum – need for protection Coverings • Coverings: • meninges (3) • Subarachnoid space • location • composition • diagnostic use Spinal Nerves • Caudal equina Finer Structures of Spinal Cord • Gray Matter • composition • function • horns (2) • horns form roots (2) • gray commisure • central canal Finer Structures of Spinal Cord • White matter • arrangement • columns contain tracts • description • names The Brain •General Structure •Protection •Skeletal •Membranous The Brain • Development • Neural Plate • Neural Tube and 3 swellings The Brain • Other Structures • Ventricles • Foramen of Monroe • Cerebral Aqueduct The Brain - finer structures • Brain Stem • Medulla • location • connection • gray matter vs. white matter • function • kinds of reflexes The Brain • Brain stem • Pons • Structure • Composition • Nerves The Brain • Brain stem • Midbrain • Location • Composition: • Cerebral peduncles • Substantia nigra • Tegmentum • Corpora quadrigemina • Cerebral aqueduct The Brain • Cerebellum • Location • Structure • Cortex The Brain • Cerebellum • White Matter • Cerebellar Nuclei • Dentate Nuclei • Furrows • Divisions • Functions The Brain • Interbrain • Contains structures (2) • Location • How functions were determined Interbrain • The Thalamus • Function • Result of Injury Interbrain • The Hypothalmus • Function • Reason for these functions • Result of Injury The Brain • The Cerebrum • Size • Complexity •
    [Show full text]
  • Metabolic Responses in Discrete, Mice Brain Regions Like CC, CG, H and CQ During PTZ Induced Epileptic Seizures
    Current Neurobiology 2012; 3 (1): 31-38 ISSN 0975-9042 Scientific Publishers of India Metabolic responses in discrete, Mice brain regions like CC, CG, H and CQ during PTZ induced epileptic seizures. K. K. Therisa and P.V. Desai Department of Zoology, Goa University, Taleigao Plateau, Goa 403206, India. Abstract Epilepsy, a neurological disorder with recurrent seizures, involves disruption of different metabolic enzymes and its related metabolites altering the normal processes of metabolism, either during the onset or post epilepsy in the brain. In the present work, it is convincingly, observed that the Mice brain regions such as Corpus callosum (CC), Cingulate gyrus (CG), Hippocampus (H) and Corpora quadrigemina (CQ) shows significant changes in the activi- ties of metabolic enzymes such as AST, ALT, LDH; ATPases like Na +, K +-ATPase, Mg 2+ - ATPase, Ca 2+ -ATPase along with their metabolites such as Glucose, Pyruvate, Lactate and Glutamate, altering the metabolic integrity during Pentylenetetrazole (PTZ) induced epilep- tic seizure. We report from the present work that, H and CG are affected completely during epileptic seizure as compared to its control but CC and CQ shows partly altered as far as metabolism in brain is concerned. Keywords: Corpus callosum, Hippocampus, Cingulate gyrus, Corpora Quadrigemina, Metabolic enzymes and metabo- lites. Accepted April 07 2012 Introduction may overlap with other frontal lobe epilepsy syndromes. But, an aberrant behaviors observed in epileptic patients Epilepsy, involves a disruption of brain energy homeosta- completely resolved after lesionectomy of Cingulate sis and is potentially manageable through principles of gyrus [6]. Hippocampus and Cingulate gyrus forms the metabolic control theory.
    [Show full text]
  • The Brain and Behavior
    This page intentionally left blank The Brain and Behavior The Brain and Behavior An Introduction to Behavioral Neuroanatomy Third Edition David L. Clark Nash N. Boutros Mario F. Mendez CAMBRIDGE UNIVERSITY PRESS Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo, Delhi, Dubai, Tokyo Cambridge University Press The Edinburgh Building, Cambridge CB2 8RU, UK Published in the United States of America by Cambridge University Press, New York www.cambridge.org Information on this title: www.cambridge.org/9780521142298 © D. Clark, N. Boutros, M. Mendez 2010 This publication is in copyright. Subject to statutory exception and to the provision of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published in print format 2010 ISBN-13 978-0-511-77469-0 eBook (EBL) ISBN-13 978-0-521-14229-8 Paperback Cambridge University Press has no responsibility for the persistence or accuracy of urls for external or third-party internet websites referred to in this publication, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate. Every effort has been made in preparing this book to provide accurate and up-to- date information which is in accord with accepted standards and practice at the time of publication. Although case histories are drawn from actual cases, every effort has been made to disguise the identities of the individuals involved. Nevertheless, the authors, editors, and publishers can make no warranties that the information contained herein is totally free from error, not least because clinical standards are constantly changing through research and regulation.
    [Show full text]
  • Human Physiology/The Nervous System 1 Human Physiology/The Nervous System
    Human Physiology/The Nervous System 1 Human Physiology/The Nervous System ← Integumentary System — Human Physiology — Senses → Homeostasis — Cells — Integumentary — Nervous — Senses — Muscular — Blood — Cardiovascular — Immune — Urinary — Respiratory — Gastrointestinal — Nutrition — Endocrine — Reproduction (male) — Reproduction (female) — Pregnancy — Genetics — Development — Answers The central nervous system includes the brain and spinal cord. The brain and spinal cord are protected by bony structures, membranes, and fluid. The brain is held in the cranial cavity of the skull and it consists of the cerebrum, cerebellum, and the brain stem. The nerves involved are cranial nerves and spinal nerves. Overview of the entire nervous system The nervous system has three main functions: sensory input, integration of data and motor output. Sensory input is when the body gathers information or data, by way of neurons, glia and synapses. The nervous system is composed of excitable nerve cells (neurons) and synapses that form between the neurons and connect them to centers throughout the body or to other neurons. These neurons operate on excitation or inhibition, and although nerve cells can vary in size and location, their communication with one another determines their function. These nerves conduct impulses from sensory receptors to the brain and spinal cord. The data is then processed by way of integration of data, which occurs only in the brain. After the brain has processed the information, impulses are then conducted from the brain and spinal cord to muscles and glands, which is called motor output. Glia cells are found within tissues and are not excitable but help with myelination, ionic regulation and extracellular fluid. The nervous system is comprised of two major parts, or subdivisions, the central nervous system (CNS) and the peripheral nervous system Nervous system (PNS).
    [Show full text]
  • Chapter 3: Internal Anatomy of the Central Nervous System
    10353-03_CH03.qxd 8/30/07 1:12 PM Page 82 3 Internal Anatomy of the Central Nervous System LEARNING OBJECTIVES Nuclear structures and fiber tracts related to various functional systems exist side by side at each level of the After studying this chapter, students should be able to: nervous system. Because disease processes in the brain • Identify the shapes of corticospinal fibers at different rarely strike only one anatomic structure or pathway, there neuraxial levels is a tendency for a series of related and unrelated clinical symptoms to emerge after a brain injury. A thorough knowl- • Recognize the ventricular cavity at various neuroaxial edge of the internal brain structures, including their shape, levels size, location, and proximity, makes it easier to understand • Recognize major internal anatomic structures of the their functional significance. In addition, the proximity of spinal cord and describe their functions nuclear structures and fiber tracts explains multiple symp- toms that may develop from a single lesion site. • Recognize important internal anatomic structures of the medulla and explain their functions • Recognize important internal anatomic structures of the ANATOMIC ORIENTATION pons and describe their functions LANDMARKS • Identify important internal anatomic structures of the midbrain and discuss their functions Two distinct anatomic landmarks used for visual orientation to the internal anatomy of the brain are the shapes of the • Recognize important internal anatomic structures of the descending corticospinal fibers and the ventricular cavity forebrain (diencephalon, basal ganglia, and limbic (Fig. 3-1). Both are present throughout the brain, although structures) and describe their functions their shape and size vary as one progresses caudally from the • Follow the continuation of major anatomic structures rostral forebrain (telencephalon) to the caudal brainstem.
    [Show full text]
  • Brain Anatomy
    BRAIN ANATOMY Adapted from Human Anatomy & Physiology by Marieb and Hoehn (9th ed.) The anatomy of the brain is often discussed in terms of either the embryonic scheme or the medical scheme. The embryonic scheme focuses on developmental pathways and names regions based on embryonic origins. The medical scheme focuses on the layout of the adult brain and names regions based on location and functionality. For this laboratory, we will consider the brain in terms of the medical scheme (Figure 1): Figure 1: General anatomy of the human brain Marieb & Hoehn (Human Anatomy and Physiology, 9th ed.) – Figure 12.2 CEREBRUM: Divided into two hemispheres, the cerebrum is the largest region of the human brain – the two hemispheres together account for ~ 85% of total brain mass. The cerebrum forms the superior part of the brain, covering and obscuring the diencephalon and brain stem similar to the way a mushroom cap covers the top of its stalk. Elevated ridges of tissue, called gyri (singular: gyrus), separated by shallow groves called sulci (singular: sulcus) mark nearly the entire surface of the cerebral hemispheres. Deeper groves, called fissures, separate large regions of the brain. Much of the cerebrum is involved in the processing of somatic sensory and motor information as well as all conscious thoughts and intellectual functions. The outer cortex of the cerebrum is composed of gray matter – billions of neuron cell bodies and unmyelinated axons arranged in six discrete layers. Although only 2 – 4 mm thick, this region accounts for ~ 40% of total brain mass. The inner region is composed of white matter – tracts of myelinated axons.
    [Show full text]
  • BRAINSTEM,CEREBELLUM, DIENCEPHALON-Dr. Kibe INTRODUCTION the Brain Is One of the Largest Organs in Adults
    THE CENTRAL NERVOUS SYSTEM BRAINSTEM,CEREBELLUM, DIENCEPHALON-Dr. Kibe INTRODUCTION The brain is one of the largest organs in adults. It consists approximately 100 billion neurons and 900 billion glia . And it weighs about 1.4 kg in adults Neurons of the brain undergo mitotic cell division only during the prenatal period and the first few months of postnatal life. No increase in number after that. Malnutrition during the crucial prenatal months of neuron multiplication is reported to hinder the process and result in fewer brain cells. The brain attains full size by about the eighteenth year but grows rapidly only during the first 9 years or so. BRAINSTEM • Three divisions of the brain make up the brainstem . • The medulla oblongata forms the lowest part of the brainstem, • The midbrain forms the uppermost part, • The pons lies between them, that is, above the medulla and below the midbrain. BRAIN STEM AND DIENCEPHALON Medulla Oblongata • The medulla oblongata is the part of the brain that attaches to the spinal cord. • It measures only a few centimeters (about 1 inch) in length and is separated from the pons above by a horizontal groove. • It is composed of white matter and a network of gray and white matter called the reticular formation • The pyramids are two bulges of white matter located on the ventral surface of the medulla. Fibers of the so-called pyramidal tracts form the pyramids. • The olive of the medulla is an oval projection appearing one on each side of the ventral surface of the medulla, lateral to the pyramids.
    [Show full text]
  • Nervous System and Eye Dissection
    Nervous System and Eye Dissection Friday 14th th • Monday 10 • Finish notes • Take notes on Slides 4-10 • Write pre-reflection for dissection (write • Introduction to Nervous System separate paper) • Brain Metaphor Activity • Quiz Each other on notes • Dissection lab Safety • • th Study Word Parts and Eye Dissection Tuesday 11 Terms • Guest Speaker th • Wednesday 12 Staple following order to turn in Monday 17th • Take notes on slides 11-13 and Eye 1. Brain Metaphor Activity Dissection PowerPoint (Online) 2. Notes Neuron , CNS, PNS • Thursday 13th 3. Eye terms • Take notes on Slides 14-19 4. Senses – Mechanoreceptors and • Notes for lab on Monday Thermoreceptors • Mechanoreceptors and 5. Pre-Reflection (write separate paper) Thermoreceptors • Take the Quizizz’s once you have finished and reviewed the notes. https://join.quizizz.com • Chapter 5 and Nervous System Code: 284401 • Sheep Eye Dissection Code : 709952 • Nervous System Code: 73542 • Senses and Eyes Code: 831720 1. Draw neuron , label parts, and functions 2. Quiz Self of Nervous Cell and Functions 3. http://myclass.theinspiredinstructor.com/science/health_diagrams/ Neuron_Label.htm The Nervous System is divided into two parts: 1. Central NS a. Brain and spinal cord b. Processes info 2. Peripheral NS a. Mainly of nerves, sense organs b. Connect the CNS to every other part of the body c. Receives/sends info to and from the body 3. Nerves that transmit signals from the brain are called motor or efferent nerves 4. Nerves that transmit information from the body to the CNS are called sensory or afferent. Central Nervous System •Cerebrum •Frontal •Parietal •Occipital •Temporal •Cerebellum •Brain Stem Peripheral Nervous System Divided into three parts: 1.
    [Show full text]
  • The Somatic Nervous System Mimi Jakoi, Phd Jennifer Carbrey, Phd
    Introductory Human Physiology ©copyright Jennifer Carbrey & Emma Jakoi The Somatic Nervous System Mimi Jakoi, PhD Jennifer Carbrey, PhD The underlined headings correspond to the two Somatic Nervous system videos. 1. Introduction and structure The efferent portion of the peripheral nervous system consists of the somatic nervous system and the autonomic nervous system. The autonomic nervous system controls the function of glands, smooth muscle, cardiac muscle, and the neurons of the GI tract. It is composed of two neurons in series that can either excite or inhibit the target organ. In contrast, the somatic nervous system contains single neurons that excite skeletal muscles. The movements controlled by the somatic nervous system can be voluntary or involuntary (reflexes). Motor Unit The axons of motor neurons are myelinated and have large diameters for fast conduction of action potentials. As the axon approaches a skeletal muscle fiber (muscle cell) it usually branches to form synapses with anywhere from three to one thousand muscle fibers. However, each muscle fiber is usually innervated by only a single neuron. A motor unit consists of a neuron and all of the muscle fibers it innervates. A single neuron innervates fibers from only one muscle and the innervated muscle fibers are usually spread throughout the muscle. The portion of the skeletal muscle fiber plasma membrane that synapses with the motor neuron axon is called the motor end plate. Once an action potential arrives at the axon terminal, the depolarization of the membrane opens voltage-gated calcium channels (Fig. 1). An increase in intracellular calcium at the terminal causes release of acetylcholine vesicles into the neuromuscular junction.
    [Show full text]
  • Nervous System Central Nervous System Peripheral Nervous System
    Peripheral Nervous System Involuntary reflexes (spinal cord); Organization of Nervous System: voluntary actions (higher brain centers) Nervous system Integration Central nervous system Peripheral nervous system (CNS) (PNS) Motor Sensory output input Brain Spinal cord Motor division Sensory division (efferent) (afferent) Autonomic nervous system Somatic nervous system (involuntary; smooth & cardiac muscle) (voluntary; skeletal muscle) Sympathetic division Parasympathetic division Peripheral Nervous System Motor Units: Motor Unit: A single motor neuron and all the muscle fibers innervated by it (motor unit = all-or-none) Motor unit size dictates control: Fine Control / Rapid Reaction: 1-10 fibers / MU (e.g., ocular muscles) Gross Control / Slow Reaction: 1000’s fibers / MU (e.g., quadriceps) Recruitment: Addition of motor units to produce smooth, steady muscle tension (multiple fiber summation) Motoneuron Pool: Set of motor neurons innervating Small large motor units activated… muscle fibers within the same muscle • Varying thresholds Motor units overlap; provides coordination Marieb & Hoehn – Figure 9.13 1 Peripheral Nervous System Types of Motor Neurons: 1) Alpha () motor neurons: • Give rise to large Type A alpha (A) motor nerve fibers (~ 14 µm diameter) • Innervate extrafusal skeletal muscle fibers (generate force) 2) Gamma () motor neurons: • Give rise to small Type A gamma (Aγ) motor nerve fibers (~ 5 µm diameter) • Innervate intrafusal muscle fibers (small, specialized fibers – muscle spindle) What is the length of the muscle? Proper
    [Show full text]