Developmental Anomalies of the Cranial Nerve Motor Nuclei
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Cranial Nerves
Cranial Nerves (1,5,7,8,9,10,11 and 12) Slides not included 9th and 10th Cranial 11th and 12th Cranial 8th Cranial Nerve 5th and 7th Cranial 1st Cranial Nerve Nerves Nerves Nerves (3,7,11,12,13,21,23,24) - (10,16) (12,23) Slides included: (14 to 17) *Slides that are not included mostly are slides of summaries or pictures. Nouf Alabdulkarim. Med 435 Olfactory Nerve [The 1st Cranial Nerve] Special Sensory Olfactory pathway 1st order neuron Receptors Axons of 1st order Neurons Olfactory receptors are specialized, ciliated nerve cells The axons of these bipolar cells 12 -20 fibers form the that lie in the olfactory epithelium. true olfactory nerve fibers. Which passes through the cribriform plate of ethmoid → They join the olfactory bulb Preliminary processing of olfactory information It is within the olfactory bulb, which contains interneurones and large Mitral cells; axons from the latter leave the bulb to form the olfactory tract. nd 2 order neuron • It is formed by the Mitral cells of olfactory bulb. • The axons of these cells form the olfactory tract. • Each tract divides into 2 roots at the anterior perforated substance: Lateral root Medial root Carries olfactory fibers to end in cortex of the Uncus & • crosses midline through anterior commissure adjacent part of Hippocampal gyrus (center of smell). and joins the uncrossed lateral root of opposite side. • It connects olfactory centers of 2 cerebral hemispheres. • So each olfactory center receives smell sensation from both halves of nasal cavity. NB. Olfactory pathway is the only sensory pathway which reaches the cerebral cortex without passing through the Thalamus . -
Pharnygeal Arch Set - Motor USMLE, Limited Edition > Neuroscience > Neuroscience
CNs 5, 7, 9, 10 - Pharnygeal Arch Set - Motor USMLE, Limited Edition > Neuroscience > Neuroscience PHARYNGEAL ARCH SET, CNS 5, 7, 9, 10 • They are derived from the pharyngeal (aka branchial) arches • They have special motor and autonomic motor functions CRANIAL NERVES EXIT FROM THE BRAINSTEM CN 5, the trigeminal nerve exits the mid/lower pons.* CN 7, the facial nerve exits the pontomedullary junction.* CN 9, the glossopharyngeal nerve exits the lateral medulla.* CN 10, the vagus nerve exits the lateral medulla.* CRANIAL NERVE NUCLEI AT BRAINSTEM LEVELS Midbrain • The motor trigeminal nucleus of CN 5. Nerve Path: • The motor division of the trigeminal nerve passes laterally to enter cerebellopontine angle cistern. Pons • The facial nucleus of CN 7. • The superior salivatory nucleus of CN 7. Nerve Path: • CN 7 sweeps over the abducens nucleus as it exits the brainstem laterally in an internal genu, which generates a small bump in the floor of the fourth ventricle: the facial colliculus • Fibers emanate from the superior salivatory nucleus, as well. Medulla • The dorsal motor nucleus of the vagus, CN 10 • The inferior salivatory nucleus, CN 9 1 / 3 • The nucleus ambiguus, CNs 9 and 10. Nerve Paths: • CNs 9 and 10 exit the medulla laterally through the post-olivary sulcus to enter the cerebellomedullary cistern. THE TRIGEMINAL NERVE, CN 5  • The motor division of the trigeminal nerve innervates the muscles of mastication • It passes ventrolaterally through the cerebellopontine angle cistern and exits through foramen ovale as part of the mandibular division (CN 5[3]). Clinical Correlation - Trigeminal Neuropathy THE FACIAL NERVE, CN 7  • The facial nucleus innervates the muscles of facial expression • It spans from the lower pons to the pontomedullary junction. -
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 -
GLOSSARY Glossary Adapted with Permission from R
GLOSSARY Glossary adapted with permission from R. Kalb (ed.) Multiple Sclerosis: The Questions You Have: The Answers You Need (5th ed.) New York: Demos Medical Publishing, 2012. This glossary is available in its entirety (as well as additional MS terms) online at nationalMSsociety.org/glossary. 106 | KNOWLEDGE IS POWER 106 | KNOWLEDGE IS POWER Americans with Disabilities Act Blood-brain barrier (ADA) A semi-permeable cell layer around The first comprehensive legislation blood vessels in the brain and spinal to prohibit discrimination on the cord that prevents large molecules, basis of disability. The ADA (passed immune cells, and potentially in 1990) guarantees full participation damaging substances and disease- in society to people with disabilities. causing organisms (e.g., viruses) from The four areas of social activity passing out of the blood stream into the covered by the ADA are employment; central nervous system (brain, spinal public services and accommodations; cord and optic nerves). A break in the transportation; and communications blood-brain barrier may underlie the Autoimmune(e.g., telephone disease services). Centraldisease process nervous in system MS. A process in which the body’s immune The part of the nervous system that system causes illness by mistakenly includes the brain, optic nerves, and attacking healthy cells, organs or tissues Cerebrospinalspinal cord. fluid (CSF) in the body that are essential for good health. In multiple sclerosis, the specific antigen — or target — that the immune A watery, colorless, clear fluid that cells are sensitized to attack remains bathes and protects the brain and unknown, which is why MS is considered spinal cord. -
Progress and Challenges in Probing the Human Brain
University of Pennsylvania ScholarlyCommons Neuroethics Publications Center for Neuroscience & Society 10-2015 Progress and Challenges in Probing the Human Brain Russell A. Poldrack Martha J. Farah University of Pennsylvania, [email protected] Follow this and additional works at: https://repository.upenn.edu/neuroethics_pubs Part of the Bioethics and Medical Ethics Commons, Neuroscience and Neurobiology Commons, and the Neurosciences Commons Recommended Citation Poldrack, R. A., & Farah, M. J. (2015). Progress and Challenges in Probing the Human Brain. Nature, 526 (7573), 371-379. http://dx.doi.org/10.1038/nature15692 This paper is posted at ScholarlyCommons. https://repository.upenn.edu/neuroethics_pubs/136 For more information, please contact [email protected]. Progress and Challenges in Probing the Human Brain Abstract Perhaps one of the greatest scientific challenges is to understand the human brain. Here we review current methods in human neuroscience, highlighting the ways that they have been used to study the neural bases of the human mind. We begin with a consideration of different levels of description relevant to human neuroscience, from molecules to large-scale networks, and then review the methods that probe these levels and the ability of these methods to test hypotheses about causal mechanisms. Functional MRI is considered in particular detail, as it has been responsible for much of the recent growth of human neuroscience research. We briefly er view its inferential strengths and weaknesses and present examples of new analytic approaches that allow inferences beyond simple localization of psychological processes. Finally, we review the prospects for real-world applications and new scientific challenges for human neuroscience. -
The Use of Cholinesterase Techniques to Study Topographical Localization in the Hypoglossal Nucleus of the Rat
J. Anat. (1971), 110, 2, pp. 203-213 203 With 1O figures Printed in Great Britain The use of cholinesterase techniques to study topographical localization in the hypoglossal nucleus of the rat P. R. LEWIS*, B. A. FLUMERFELTt AND C. C. D. SHUTE* Department ofAnatomy, University of Cambridge (Accepted 4 August 1971) INTRODUCTION The hypoglossal nucleus is perhaps the most suitable motor nucleus for the experi- mental study of the cytological changes occurring in cholinergic neurons following axotomy. The cells are large and the nucleus is easy to find even in a fresh unfixed brain; furthermore, the nucleus is so close to the midline that it is possible to use one side as a control for the other with complete confidence and to view equivalent control and experimental neurons simultaneously at quite high magnifications. An added advantage is that the hypoglossal nerve trunk in the neck region is almost purely motor; the central effects of axotomy are therefore not complicated by any significant loss of sensory fibres. Our interest in the nucleus was heightened by the discovery that in the rat a group of neurons at the caudal end contained a high concentration of an enzyme resembling in its histochemical reactions pseudocholin- esterase (Shute & Lewis, 1963). The enzyme will hydrolyse acetylthiocholine and is inhibited by ethopropazine, but its most characteristic property is a rapid hydrolysis of butyrylthiocholine; BuChE would thus seem an appropriate abbreviation to distinguish it from true cholinesterase (AChE), the enzyme typically present in motor neurons. It was shown originally by Schwarzacher (1958) that there is a marked decrease in AChE activity in hypoglossal neurons during the second and third weeks following axotomy (although he also looked at the response of pseudocholinesterase he did not comment on the specifically staining group of cells). -
Basic Brain Anatomy
Chapter 2 Basic Brain Anatomy Where this icon appears, visit The Brain http://go.jblearning.com/ManascoCWS to view the corresponding video. The average weight of an adult human brain is about 3 pounds. That is about the weight of a single small To understand how a part of the brain is disordered by cantaloupe or six grapefruits. If a human brain was damage or disease, speech-language pathologists must placed on a tray, it would look like a pretty unim- first know a few facts about the anatomy of the brain pressive mass of gray lumpy tissue (Luria, 1973). In in general and how a normal and healthy brain func- fact, for most of history the brain was thought to be tions. Readers can use the anatomy presented here as an utterly useless piece of flesh housed in the skull. a reference, review, and jumping off point to under- The Egyptians believed that the heart was the seat standing the consequences of damage to the structures of human intelligence, and as such, the brain was discussed. This chapter begins with the big picture promptly removed during mummification. In his and works down into the specifics of brain anatomy. essay On Sleep and Sleeplessness, Aristotle argued that the brain is a complex cooling mechanism for our bodies that works primarily to help cool and The Central Nervous condense water vapors rising in our bodies (Aristo- tle, republished 2011). He also established a strong System argument in this same essay for why infants should not drink wine. The basis for this argument was that The nervous system is divided into two major sec- infants already have Central nervous tions: the central nervous system and the peripheral too much moisture system The brain and nervous system. -
Late Effects of Retinoic Acid on Neural Crest and Aspects of Rhombomere Identity
Development 122, 783-793 (1996) 783 Printed in Great Britain © The Company of Biologists Limited 1996 DEV2020 Late effects of retinoic acid on neural crest and aspects of rhombomere identity Emily Gale1, Victoria Prince2, Andrew Lumsden3, Jon Clarke4, Nigel Holder1 and Malcolm Maden1 1Developmental Biology Research Centre, The Randall Institute, King’s College London, 26-29 Drury Lane, London WC2B 5RL, UK 2Department of Molecular Biology, Princeton University, Washington Road, Princeton, NJ 08544, USA 3MRC Brain Development Programme, Division of Anatomy and Cell Biology, UMDS, Guy’s Hospital, London SE1 9RT, UK 4Department of Anatomy and Developmental Biology, University College, Windeyer Building, Cleveland St., London W1P 6DB, UK SUMMARY We exposed st.10 chicks to retinoic acid (RA), both ment of the facial ganglion in addition to a mis-direction of globally, and locally to individual rhombomeres, to look at the extensions of its distal axons and a dramatic decrease its role in specification of various aspects of hindbrain in the number of contralateral vestibuloacoustic neurons derived morphology. Previous studies have looked at RA normally seen in r4. Only this r4-specific neuronal type is exposure at earlier stages, during axial specification. Stage affected in r4; the motor neuron projections seem normal 10 is the time of morphological segmentation of the in experimental animals. The specificity of this result, hindbrain and is just prior to neural crest migration. combined with the loss of Hoxb-1 expression in r4 and the Rhombomere 4 localised RA injections result in specific work by Krumlauf and co-workers showing gain of con- alterations of pathways some crest cells that normally tralateral neurons co-localised with ectopic Hoxb-1 migrate to sites of differentiation of neurogenic derivatives. -
Clonal Dispersion During Neural Tube Formation 4097 of Neuromeres
Development 126, 4095-4106 (1999) 4095 Printed in Great Britain © The Company of Biologists Limited 1999 DEV2458 Successive patterns of clonal cell dispersion in relation to neuromeric subdivision in the mouse neuroepithelium Luc Mathis1,*, Johan Sieur1, Octavian Voiculescu2, Patrick Charnay2 and Jean-François Nicolas1,‡ 1Unité de Biologie moléculaire du Développement, Institut Pasteur, 25, rue du Docteur Roux, 75724 Paris Cedex 15, France 2Unité INSERM 368, Ecole Normale Supérieure, 46 rue d’Ulm, 75230 Paris Cedex 05, France *Present address: Beckman Institute (139-74), California Institute of Technology, Pasadena, CA, 91125, USA ‡Author for correspondence (e-mail: [email protected]) Accepted 5 July; published on WWW 23 August 1999 SUMMARY We made use of the laacz procedure of single-cell labelling the AP and DV axis of the neural tube. A similar sequence to visualize clones labelled before neuromere formation, in of AP cell dispersion followed by an arrest of AP cell 12.5-day mouse embryos. This allowed us to deduce two dispersion, a preferential DV cell dispersion and then by a successive phases of cell dispersion in the formation of the coherent neuroepithelial growth, is also observed in the rhombencephalon: an initial anterior-posterior (AP) cell spinal cord and mesencephalon. This demonstrates that a dispersion, followed by an asymmetrical dorsoventral (DV) similar cascade of cell events occurs in these different cell distribution during which AP cell dispersion occurs in domains of the CNS. In the prosencephalon, differences in territories smaller than one rhombomere. We conclude that spatial constraints may explain the variability in the the general arrest of AP cell dispersion precedes the onset orientation of cell clusters. -
The Human Brain Hemisphere Controls the Left Side of the Body and the Left What Makes the Human Brain Unique Is Its Size
About the brain Cerebrum (also known as the The brain is made up of around 100 billion nerve cells - each one cerebral cortex or forebrain) is connected to another 10,000. This means that, in total, we The cerebrum is the largest part of the brain. It is split in to two have around 1,000 trillion connections in our brains. (This would ‘halves’ of roughly equal size called hemispheres. The two be written as 1,000,000,000,000,000). These are ultimately hemispheres, the left and right, are joined together by a bundle responsible for who we are. Our brains control the decisions we of nerve fibres called the corpus callosum. The right make, the way we learn, move, and how we feel. The human brain hemisphere controls the left side of the body and the left What makes the human brain unique is its size. Our brains have a hemisphere controls the right side of the body. The cerebrum is larger cerebral cortex, or cerebrum, relative to the rest of the The human brain is the centre of our nervous further divided in to four lobes: frontal, parietal, occipital, and brain than any other animal. (See the Cerebrum section of this temporal, which have different functions. system. It is the most complex organ in our fact sheet for further information.) This enables us to have abilities The frontal lobe body and is responsible for everything we do - such as complex language, problem-solving and self-control. The frontal lobe is located at the front of the brain. -
Stages of Embryonic Development of the Zebrafish
DEVELOPMENTAL DYNAMICS 2032553’10 (1995) Stages of Embryonic Development of the Zebrafish CHARLES B. KIMMEL, WILLIAM W. BALLARD, SETH R. KIMMEL, BONNIE ULLMANN, AND THOMAS F. SCHILLING Institute of Neuroscience, University of Oregon, Eugene, Oregon 97403-1254 (C.B.K., S.R.K., B.U., T.F.S.); Department of Biology, Dartmouth College, Hanover, NH 03755 (W.W.B.) ABSTRACT We describe a series of stages for Segmentation Period (10-24 h) 274 development of the embryo of the zebrafish, Danio (Brachydanio) rerio. We define seven broad peri- Pharyngula Period (24-48 h) 285 ods of embryogenesis-the zygote, cleavage, blas- Hatching Period (48-72 h) 298 tula, gastrula, segmentation, pharyngula, and hatching periods. These divisions highlight the Early Larval Period 303 changing spectrum of major developmental pro- Acknowledgments 303 cesses that occur during the first 3 days after fer- tilization, and we review some of what is known Glossary 303 about morphogenesis and other significant events that occur during each of the periods. Stages sub- References 309 divide the periods. Stages are named, not num- INTRODUCTION bered as in most other series, providing for flexi- A staging series is a tool that provides accuracy in bility and continued evolution of the staging series developmental studies. This is because different em- as we learn more about development in this spe- bryos, even together within a single clutch, develop at cies. The stages, and their names, are based on slightly different rates. We have seen asynchrony ap- morphological features, generally readily identi- pearing in the development of zebrafish, Danio fied by examination of the live embryo with the (Brachydanio) rerio, embryos fertilized simultaneously dissecting stereomicroscope. -
Hemisus Marmoratum
Neuroscience Letters 244 (1998) 5–8 Distribution of hypoglossal motor neurons innervating the prehensile tongue of the African pig-nosed frog, Hemisus marmoratum Curtis W. Andersona,*, Kiisa C. Nishikawab, Joyce Keifera aDepartment of Anatomy and Structural Biology, University of South Dakota School of Medicine, Vermillion, SD 57069, USA bDepartment of Biological Sciences, Physiology and Functional Morphology Group, Northern Arizona University, Flagstaff, AZ 86011, USA Received 15 December 1997; received in revised form 28 January 1998; accepted 28 January 1998 Abstract Using retrograde neuronal tracers, a study of the distribution of hypoglossal motor neurons innervating the tongue musculature was performed in the African pig-nosed frog, Hemisus marmoratum. This species is a radically divergent anuran amphibian with a prehensile tongue that can be aimed in three dimensions relative to the head. The results illustrate a unique rostrocaudal distribution of the ventrolateral hypoglossal nucleus and an unusually large number of motor neurons within this cell group. During the evolution of the long, prehensile tongue of Hemisus, the motor neurons innervating the tongue have greatly increased in number and have become more caudally distributed in the brainstem and spinal cord compared to other anurans. These observations have implications for understanding neuronal reconfiguring of motoneurons for novel morphologies requiring new muscle activation patterns. 1998 Elsevier Science Ireland Ltd. Keywords: Anuran amphibian; Hypoglossal nerve; Motor nuclei; Tongue Recent studies of feeding in anurans have revealed a hylidae [12,15]. In hydrostatic elongation, the tongue diversity of tongue morphologies and feeding mechanisms protractor muscle (M. genioglossus) has two types of mus- [1,5,7,8,10,11,15].