The Mechanics of Hearing Jonathan Ashmore 1
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Pathophysiological Mechanisms and Functional Hearing Consequences of Auditory Neuropathy
doi:10.1093/brain/awv270 BRAIN 2015: 138; 3141–3158 | 3141 REVIEW ARTICLE Pathophysiological mechanisms and functional hearing consequences of auditory neuropathy Gary Rance1 and Arnold Starr2 The effects of inner ear abnormality on audibility have been explored since the early 20th century when sound detection measures were first used to define and quantify ‘hearing loss’. The development in the 1970s of objective measures of cochlear hair cell Downloaded from function (cochlear microphonics, otoacoustic emissions, summating potentials) and auditory nerve/brainstem activity (auditory brainstem responses) have made it possible to distinguish both synaptic and auditory nerve disorders from sensory receptor loss. This distinction is critically important when considering aetiology and management. In this review we address the clinical and pathophysiological features of auditory neuropathy that distinguish site(s) of dysfunction. We describe the diagnostic criteria for: (i) presynaptic disorders affecting inner hair cells and ribbon synapses; (ii) postsynaptic disorders affecting unmyelinated auditory http://brain.oxfordjournals.org/ nerve dendrites; (iii) postsynaptic disorders affecting auditory ganglion cells and their myelinated axons and dendrites; and (iv) central neural pathway disorders affecting the auditory brainstem. We review data and principles to identify treatment options for affected patients and explore their benefits as a function of site of lesion. 1 Department of Audiology and Speech Pathology, The University of Melbourne, -
Reticular Lamina and Basilar Membrane Vibrations in Living Mouse Cochleae
Reticular lamina and basilar membrane vibrations in living mouse cochleae Tianying Rena,1, Wenxuan Hea, and David Kempb aOregon Hearing Research Center, Department of Otolaryngology, Oregon Health & Science University, Portland, OR 97239; and bUniversity College London Ear Institute, University College London, London WC1E 6BT, United Kingdom Edited by Mario A. Ruggero, Northwestern University, Evanston, IL, and accepted by Editorial Board Member Peter L. Strick July 1, 2016 (received for review May 9, 2016) It is commonly believed that the exceptional sensitivity of mamma- (Fig. 1 A and B and Materials and Methods). The results from this lian hearing depends on outer hair cells which generate forces for study do not demonstrate the commonly expected cochlear local amplifying sound-induced basilar membrane vibrations, yet how feedback but instead indicate a global hydromechanical mecha- cellular forces amplify vibrations is poorly understood. In this study, nism for outer hair cells to enhance hearing sensitivity. by measuring subnanometer vibrations directly from the reticular lamina at the apical ends of outer hair cells and from the basilar Results membrane using a custom-built heterodyne low-coherence interfer- Vibrations of the Reticular Lamina and Basilar Membrane in Sensitive ometer, we demonstrate in living mouse cochleae that the sound- Cochleae. Vibrations of the reticular lamina and basilar membrane induced reticular lamina vibration is substantially larger than the measured from a sensitive cochlea are presented in Fig. 1 C–J. basilar membrane vibration not only at the best frequency but Below 50 dB sound pressure level (SPL) (0 dB SPL = 20 μPa), the surprisingly also at low frequencies. -
Sound and the Ear Chapter 2
© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Chapter© Jones & Bartlett 2 Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Sound and the Ear © Jones Karen &J. Kushla,Bartlett ScD, Learning, CCC-A, FAAA LLC © Jones & Bartlett Learning, LLC Lecturer NOT School FOR of SALE Communication OR DISTRIBUTION Disorders and Deafness NOT FOR SALE OR DISTRIBUTION Kean University © Jones & Bartlett Key Learning, Terms LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR Acceleration DISTRIBUTION Incus NOT FOR SALE OR Saccule DISTRIBUTION Acoustics Inertia Scala media Auditory labyrinth Inner hair cells Scala tympani Basilar membrane Linear scale Scala vestibuli Bel Logarithmic scale Semicircular canals Boyle’s law Malleus Sensorineural hearing loss Broca’s area © Jones & Bartlett Mass Learning, LLC Simple harmonic© Jones motion (SHM) & Bartlett Learning, LLC Brownian motion Membranous labyrinth Sound Cochlea NOT FOR SALE OR Mixed DISTRIBUTION hearing loss Stapedius muscleNOT FOR SALE OR DISTRIBUTION Compression Organ of Corti Stapes Condensation Osseous labyrinth Tectorial membrane Conductive hearing loss Ossicular chain Tensor tympani muscle Decibel (dB) Ossicles Tonotopic organization © Jones Decibel & hearing Bartlett level (dB Learning, HL) LLC Outer ear © Jones Transducer & Bartlett Learning, LLC Decibel sensation level (dB SL) Outer hair cells Traveling wave theory NOT Decibel FOR sound SALE pressure OR level DISTRIBUTION -
Status and Strategies Analysis on International Standardization of Auricular Acupuncture Points
Online Submissions:http://www.journaltcm.com J Tradit Chin Med 2013 June 15; 33(3): 408-412 [email protected] ISSN 0255-2922 © 2013 JTCM. All rights reserved. REVIEWTOPIC Status and strategies analysis on international standardization of auricular acupuncture points Lei Wang, Baixiao Zhao, Liqun Zhou aa Lei Wang, Baixiao Zhao, School of Acupuncture-Moxibus- Germany. Clinical AAP research was done in Italy, tion and Tuina, Beijing University of Chinese Medicine, Bei- Austria, Switzerland, Spain, the UK, Holland, Japan, jing 100029, China Russia, and Africa. However, AAP research was not Liqun Zhou, Department of Humanities of Traditional Chi- communicated internationally. The World Federa- nese Medicine, School of Basic Medical Sciences, Beijing Uni- tion of Acupuncture-Moxibustion Societies recom- versity of Chinese Medicine, Beijing 100029, China Supported by a Grant of Key Technology Standard Promo- mended international standard of auricular acu- tion Project (No. 2006BAK04A20) from the Ministry of Sci- puncture points (ISAAPs). Standardized nomencla- ence and Technology of China, and a Grant (No. 2009B26) ture and locations of AAPs would provide a solid from the World Federation of Acupuncture and Moxibustion basis to draft an international standard organiza- Societies tion. Correspondence to: Prof. Baixiao Zhao, School of Acu- puncture-Moxibustion and Tuina, Beijing University of Chi- CONCLUSION: Experts need to find common nese Medicine, Beijing 100029, China. baixiao100@gmail. points from different countries or regions, provide com evidence of different ideas, and list the proposal as Telephone: +86-10-64286737; +86-13911040781 a recommendation for an international standard. Accepted: January 27, 2013 © 2013 JTCM. All rights reserved. Abstract Key words: Acupuncture, ear; Reference standards; Information storage and retrieval OBJECTIVE: To supply literature for developing an international standard of auricular acupuncture points. -
Study Guide Medical Terminology by Thea Liza Batan About the Author
Study Guide Medical Terminology By Thea Liza Batan About the Author Thea Liza Batan earned a Master of Science in Nursing Administration in 2007 from Xavier University in Cincinnati, Ohio. She has worked as a staff nurse, nurse instructor, and level department head. She currently works as a simulation coordinator and a free- lance writer specializing in nursing and healthcare. All terms mentioned in this text that are known to be trademarks or service marks have been appropriately capitalized. Use of a term in this text shouldn’t be regarded as affecting the validity of any trademark or service mark. Copyright © 2017 by Penn Foster, Inc. All rights reserved. No part of the material protected by this copyright may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the copyright owner. Requests for permission to make copies of any part of the work should be mailed to Copyright Permissions, Penn Foster, 925 Oak Street, Scranton, Pennsylvania 18515. Printed in the United States of America CONTENTS INSTRUCTIONS 1 READING ASSIGNMENTS 3 LESSON 1: THE FUNDAMENTALS OF MEDICAL TERMINOLOGY 5 LESSON 2: DIAGNOSIS, INTERVENTION, AND HUMAN BODY TERMS 28 LESSON 3: MUSCULOSKELETAL, CIRCULATORY, AND RESPIRATORY SYSTEM TERMS 44 LESSON 4: DIGESTIVE, URINARY, AND REPRODUCTIVE SYSTEM TERMS 69 LESSON 5: INTEGUMENTARY, NERVOUS, AND ENDOCRINE S YSTEM TERMS 96 SELF-CHECK ANSWERS 134 © PENN FOSTER, INC. 2017 MEDICAL TERMINOLOGY PAGE III Contents INSTRUCTIONS INTRODUCTION Welcome to your course on medical terminology. You’re taking this course because you’re most likely interested in pursuing a health and science career, which entails proficiencyincommunicatingwithhealthcareprofessionalssuchasphysicians,nurses, or dentists. -
Bedside Neuro-Otological Examination and Interpretation of Commonly
J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.2004.054478 on 24 November 2004. Downloaded from BEDSIDE NEURO-OTOLOGICAL EXAMINATION AND INTERPRETATION iv32 OF COMMONLY USED INVESTIGATIONS RDavies J Neurol Neurosurg Psychiatry 2004;75(Suppl IV):iv32–iv44. doi: 10.1136/jnnp.2004.054478 he assessment of the patient with a neuro-otological problem is not a complex task if approached in a logical manner. It is best addressed by taking a comprehensive history, by a Tphysical examination that is directed towards detecting abnormalities of eye movements and abnormalities of gait, and also towards identifying any associated otological or neurological problems. This examination needs to be mindful of the factors that can compromise the value of the signs elicited, and the range of investigative techniques available. The majority of patients that present with neuro-otological symptoms do not have a space occupying lesion and the over reliance on imaging techniques is likely to miss more common conditions, such as benign paroxysmal positional vertigo (BPPV), or the failure to compensate following an acute unilateral labyrinthine event. The role of the neuro-otologist is to identify the site of the lesion, gather information that may lead to an aetiological diagnosis, and from there, to formulate a management plan. c BACKGROUND Balance is maintained through the integration at the brainstem level of information from the vestibular end organs, and the visual and proprioceptive sensory modalities. This processing takes place in the vestibular nuclei, with modulating influences from higher centres including the cerebellum, the extrapyramidal system, the cerebral cortex, and the contiguous reticular formation (fig 1). -
GLOSSARY of MEDICAL and ANATOMICAL TERMS
GLOSSARY of MEDICAL and ANATOMICAL TERMS Abbreviations: • A. Arabic • abb. = abbreviation • c. circa = about • F. French • adj. adjective • G. Greek • Ge. German • cf. compare • L. Latin • dim. = diminutive • OF. Old French • ( ) plural form in brackets A-band abb. of anisotropic band G. anisos = unequal + tropos = turning; meaning having not equal properties in every direction; transverse bands in living skeletal muscle which rotate the plane of polarised light, cf. I-band. Abbé, Ernst. 1840-1905. German physicist; mathematical analysis of optics as a basis for constructing better microscopes; devised oil immersion lens; Abbé condenser. absorption L. absorbere = to suck up. acervulus L. = sand, gritty; brain sand (cf. psammoma body). acetylcholine an ester of choline found in many tissue, synapses & neuromuscular junctions, where it is a neural transmitter. acetylcholinesterase enzyme at motor end-plate responsible for rapid destruction of acetylcholine, a neurotransmitter. acidophilic adj. L. acidus = sour + G. philein = to love; affinity for an acidic dye, such as eosin staining cytoplasmic proteins. acinus (-i) L. = a juicy berry, a grape; applied to small, rounded terminal secretory units of compound exocrine glands that have a small lumen (adj. acinar). acrosome G. akron = extremity + soma = body; head of spermatozoon. actin polymer protein filament found in the intracellular cytoskeleton, particularly in the thin (I-) bands of striated muscle. adenohypophysis G. ade = an acorn + hypophyses = an undergrowth; anterior lobe of hypophysis (cf. pituitary). adenoid G. " + -oeides = in form of; in the form of a gland, glandular; the pharyngeal tonsil. adipocyte L. adeps = fat (of an animal) + G. kytos = a container; cells responsible for storage and metabolism of lipids, found in white fat and brown fat. -
Vibration Hotspots Reveal Longitudinal Funneling of Sound-Evoked Motion in the Mammalian Cochlea
ARTICLE DOI: 10.1038/s41467-018-05483-z OPEN Vibration hotspots reveal longitudinal funneling of sound-evoked motion in the mammalian cochlea Nigel P. Cooper 1, Anna Vavakou1 & Marcel van der Heijden 1 The micromechanical mechanisms that underpin tuning and dynamic range compression in the mammalian inner ear are fundamental to hearing, but poorly understood. Here, we present new, high-resolution optical measurements that directly map sound-evoked vibra- 1234567890():,; tions on to anatomical structures in the intact, living gerbil cochlea. The largest vibrations occur in a tightly delineated hotspot centering near the interface between the Deiters’ and outer hair cells. Hotspot vibrations are less sharply tuned, but more nonlinear, than basilar membrane vibrations, and behave non-monotonically (exhibiting hyper-compression) near their characteristic frequency. Amplitude and phase differences between hotspot and basilar membrane responses depend on both frequency and measurement angle, and indicate that hotspot vibrations involve longitudinal motion. We hypothesize that structural coupling between the Deiters’ and outer hair cells funnels sound-evoked motion into the hotspot region, under the control of the outer hair cells, to optimize cochlear tuning and compression. 1 Department of Neuroscience, Erasmus MC, Room Ee 1285, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands. Correspondence and requests for materials should be addressed to M.v.d.H. (email: [email protected]) NATURE COMMUNICATIONS | (2018) 9:3054 | DOI: 10.1038/s41467-018-05483-z -
ANATOMY of EAR Basic Ear Anatomy
ANATOMY OF EAR Basic Ear Anatomy • Expected outcomes • To understand the hearing mechanism • To be able to identify the structures of the ear Development of Ear 1. Pinna develops from 1st & 2nd Branchial arch (Hillocks of His). Starts at 6 Weeks & is complete by 20 weeks. 2. E.A.M. develops from dorsal end of 1st branchial arch starting at 6-8 weeks and is complete by 28 weeks. 3. Middle Ear development —Malleus & Incus develop between 6-8 weeks from 1st & 2nd branchial arch. Branchial arches & Development of Ear Dev. contd---- • T.M at 28 weeks from all 3 germinal layers . • Foot plate of stapes develops from otic capsule b/w 6- 8 weeks. • Inner ear develops from otic capsule starting at 5 weeks & is complete by 25 weeks. • Development of external/middle/inner ear is independent of each other. Development of ear External Ear • It consists of - Pinna and External auditory meatus. Pinna • It is made up of fibro elastic cartilage covered by skin and connected to the surrounding parts by ligaments and muscles. • Various landmarks on the pinna are helix, antihelix, lobule, tragus, concha, scaphoid fossa and triangular fossa • Pinna has two surfaces i.e. medial or cranial surface and a lateral surface . • Cymba concha lies between crus helix and crus antihelix. It is an important landmark for mastoid antrum. Anatomy of external ear • Landmarks of pinna Anatomy of external ear • Bat-Ear is the most common congenital anomaly of pinna in which antihelix has not developed and excessive conchal cartilage is present. • Corrections of Pinna defects are done at 6 years of age. -
Special Ear Problem (Worksheet)
Special Ear Problem (Worksheet) anvil hammer oval window Extenal auditory canal Cochlea Ear drum stirrip organ of corti Round window Basilar membrane A) Label on the drawing above: 1. External auditory canal 2. ear drum (tympanic membrane) 3. hammer (maleus) 4. anvil (incus) 5. stirrup (stapes) 6. cochlea 7. oval window 8. round window 9. basilar membrane 10. organ of Corti B) In one or two sentences, what is the function of the outer ear The outer ear collects sound and guides it to the eardrum. C) The external auditory canal functions like a 2.5 cm closed pipe. What are the first two resonances of this pipe and how do these explain features of Figure 12-7 on page 354 of your book (Giancoli)? The first two resonances are about 3500 Hz --- the frequency where your ear is most sensitive --- and 10,5000 --- which corresponds to kinks in the curves of Fig. 12-7. D)What is the boundary between the outer ear and the middle ear? The Eardrum E) In one or two sentences, what is the function of the middle ear? The middle ear takes the pressure wave coming from the (large area) eardrum and “amplifies” the pressure by about 40 to generate a wave in the fluid of the cochlea through the (small area) oval window. F) What is the boundary between the middle ear and the inner ear? The oval window. G) In one or two sentences, what is the function of the inner ear? The inner ear generates electrical signals from the (liquid) pressure waves generated at the oval window. -
Cranial Nerve VIII
Cranial Nerve VIII Color Code Important (The Vestibulo-Cochlear Nerve) Doctors Notes Notes/Extra explanation Please view our Editing File before studying this lecture to check for any changes. Objectives At the end of the lecture, the students should be able to: ✓ List the nuclei related to vestibular and cochlear nerves in the brain stem. ✓ Describe the type and site of each nucleus. ✓ Describe the vestibular pathways and its main connections. ✓ Describe the auditory pathway and its main connections. Due to the difference of arrangement of the lecture between the girls and boys slides we will stick to the girls slides then summarize the pathway according to the boys slides. Ponto-medullary Sulcus (cerebello- pontine angle) Recall: both cranial nerves 8 and 7 emerge from the ventral surface of the brainstem at the ponto- medullary sulcus (cerebello-pontine angle) Brain – Ventral Surface Vestibulo-Cochlear (VIII) 8th Cranial Nerve o Type: Special sensory (SSA) o Conveys impulses from inner ear to nervous system. o Components: • Vestibular part: conveys impulses associated with body posture ,balance and coordination of head & eye movements. • Cochlear part: conveys impulses associated with hearing. o Vestibular & cochlear parts leave the ventral surface* of brain stem through the pontomedullary sulcus ‘at cerebellopontine angle*’ (lateral to facial nerve), run laterally in posterior cranial fossa and enter the internal acoustic meatus along with 7th (facial) nerve. *see the previous slide Auditory Pathway Only on the girls’ slides 04:14 Characteristics: o It is a multisynaptic pathway o There are several locations between medulla and the thalamus where axons may synapse and not all the fibers behave in the same manner. -
Research Reports
ARAŞTIRMALAR (ResearchUnur, Ülger, Reports) Ekinci MORPHOMETRICAL AND MORPHOLOGICAL VARIATIONS OF MIDDLE EAR OSSICLES IN THE NEWBORN* Yeni doğanlarda orta kulak kemikciklerinin morfometrik ve morfolojik varyasyonları Erdoğan UNUR 1, Harun ÜLGER 1, Nihat EKİNCİ 2 Abstract Özet Purpose: Aim of this study was to investigate the Amaç: Yeni doğanlarda orta kulak kemikciklerinin morphometric and morphologic variations of middle ear morfometrik ve morfolojik varyasyonlarını ortaya ossicles. koymak. Materials and Methods: Middle ear of 20 newborn Gereç ve yöntem: Her iki cinse ait 20 yeni doğan cadavers from both sexes were dissected bilaterally and kadavrasının orta kulak boşluğuna girilerek elde edilen the ossicles were obtained to investigate their orta kulak kemikcikleri üzerinde morfometrik ve morphometric and morphologic characteristics. morfolojik inceleme yapıldı. Results: The average of morphometric parameters Bulgular: Morfometrik sonuçlar; malleus’un toplam showed that the malleus was 7.69 mm in total length with uzunluğu 7.69 mm, manibrium mallei’nin uzunluğu 4.70 an angle of 137 o; the manibrium mallei was 4.70 mm, mm, caput mallei ve processus lateralis arasındaki and the total length of head and neck was 4.85 mm; the uzaklık 4.85 mm, manibrium mallei’nin ekseni ve caput incus had a total length of 6.47 mm, total width of 4.88 mallei arasındaki açı 137 o, incus’un toplam uzunluğu mm , and a maximal distance of 6.12 mm between the 6.47 mm, toplam genişliği 4.88 mm, crus longum ve tops of the processes, with an angle of 99.9 o; the stapes breve’nin uçları arasındaki uzaklık 6.12 mm, cruslar had a total height of 3.22 mm, with stapedial base being arasındaki açı 99.9 o, stapesin toplam uzunluğu 2.57 mm in length and 1.29 mm in width.