Show Advanced Search

REFINE YOUR SEARCH:

Containing Text
- - -
+
Filter by author or institution
GO
Filter by publication date
From:
October, 2006
Until:
Today
Filter by journal section

Filter by science education

 
 
Ear, External: The outer part of the hearing system of the body. It includes the shell-like Ear auricle which collects sound, and the External ear canal, the Tympanic membrane, and the External ear cartilages.

Ear Exam

JoVE 10148

Source: Richard Glickman-Simon, MD, Assistant Professor, Department of Public Health and Community Medicine, Tufts University School of Medicine, MA

This video describes the examination of the ear, beginning with a review of its surface and interior anatomy (Figure 1). The cartilaginous auricle consists of the helix, antihelix, earlobe, and tragus. The mastoid process is positioned just behind the earlobe. The slightly curving auditory canal ends at the tympanic membrane, which transmits sound waves collected by the external ear to the air-filled middle ear. The Eustachian tube connects to the middle ear with the nasopharynx. Vibrations of the tympanic membrane transmit to the three connected ossicles of the middle ear (the malleus, incus, and stapes). The vibrations are transformed into electrical signals in the inner ear, and then carried to the brain by the cochlear nerve. Hearing, therefore, comprises a conductive phase that involves the external and middle ear, and a sensorineural phase that involves the inner ear and cochlear nerve. The auditory canal and the tympanic membrane are examined with the otoscope, a handheld instrument with a light source, a magnifier, and a disposable cone-shaped speculum. It is important to be familiar with the tympanic membrane landmarks (


 Physical Examinations II

An Introduction to Molecular Developmental Biology

JoVE 5328

Molecular signals play a major role in the complex processes occurring during embryonic development. These signals regulate activities such as cell differentiation and migration, which contribute to the formation of specific cell types and structures. The use of molecular approaches allows researchers to investigate these physical and chemical mechanisms in detail.

This video will review a brief history of the study of molecular events during development. Next, key questions asked by molecular developmental biologists today will be reviewed, followed by a discussion of several prominent methods used to answer these questions, such as staining, explant culture, and live-cell imaging. Finally, we will look at some current applications of these techniques to the study of developmental biology.


 Developmental Biology

Rodent Identification I

JoVE 10189

Source: Kay Stewart, RVT, RLATG, CMAR; Valerie A. Schroeder, RVT, RLATG. University of Notre Dame, IN

A fundamental requirement of biomedical research is the proper identification of research animals. It is essential that the right animal is utilized for procedures and data collection. Laboratory mice and rats can be identified with the following permanent methods: ear tags, ear punch codes, microchip implantation, tail tattoos for adult mice, and toe tattoos for neonates. Temporary methods of dyes and marking pens can also be used for acute studies. This video covers the technical aspects of ear tagging and punching for mice and rats, as well as the benefits of each with respect to the type of research being conducted on the animals. Knowledge of the basic manual restraint techniques for each animal (covered in a separate video) is required for these identification methods to be properly accomplished.


 Lab Animal Research

Cranial Nerves Exam II (VII-XII)

JoVE 10005

Source:Tracey A. Milligan, MD; Tamara B. Kaplan, MD; Neurology, Brigham and Women's/Massachusetts General Hospital, Boston, Massachusetts, USA

The cranial nerve examination follows the mental status evaluation in a neurological exam. However, the examination begins with observations made upon greeting the patient. For example, weakness of the facial muscles (which are innervated by cranial nerve VII) can be readily apparent during the first encounter with the patient. Cranial nerve VII (the facial nerve) also has sensory branches, which innervate the taste buds on the anterior two-thirds of the tongue and the medial aspect of the external auditory canal. Therefore, finding ipsilateral taste dysfunction in a patient with facial weakness confirms the involvement of cranial nerve VII. In addition, knowledge of the neuroanatomy helps the clinician to localize the level of the lesion: unilateral weakness of the lower facial muscles suggests a supranuclear lesion on the opposite side, while lesions involving the nuclear or infranuclear portion of the facial nerve manifest with an ipsilateral paralysis of all the facial muscles on the involved side. Cranial nerve VIII (the acoustic nerve) has two divisions: the hearing (cochlear) division and the vestibular division, which innervates the semi


 Physical Examinations III

Lymph Node Exam

JoVE 10061

Source: Richard Glickman-Simon, MD, Assistant Professor, Department of Public Health and Community Medicine, Tufts University School of Medicine, MA

The lymphatic system has two main functions: to return extracellular fluid back to the venous circulation and to expose antigenic substances to the immune system. As the collected fluid passes through lymphatic channels on its way back to the systemic circulation, it encounters multiple nodes consisting of highly concentrated clusters of lymphocytes. Most lymph channels and nodes reside deep within the body and, therefore, are not accessible to physical exam (Figure 1). Only nodes near the surface can be inspected or palpated. Lymph nodes are normally invisible, and smaller nodes are also non-palpable. However, larger nodes (>1 cm) in the neck, axillae, and inguinal areas are often detectable as soft, smooth, movable, non-tender, bean-shaped masses imbedded in subcutaneous tissue. Lymphadenopathy usually indicates an infection or, less commonly, a cancer in the area of lymph drainage. Nodes may become enlarged, fixed, firm, and/or tender depending on the pathology present. For example, a soft, tender lymph node palpable near the angle of the mandible may indicate an infected tonsil, whereas a firm, enlarged, non-tender lymph


 Physical Examinations II

The Staircase Procedure for Finding a Perceptual Threshold

JoVE 10231

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University

Psychophysics is the name for a set of methods in perceptual psychology designed in order to relate the actual intensity of stimuli to their perceptual intensity. One important aspect of psychophysics involves the measurement of perceptual thresholds: How bright does a light need to be for a person to be able to detect it? How little pressure applied to the skin is detectable? How soft can a sound be and still be heard? Put another way, what are the smallest amounts of stimulation that humans can sense? The staircase procedure is an efficient technique for identifying a person's perceptual threshold. This video will demonstrate standard methods for applying the staircase procedure in order to identify a person's auditory threshold, that is, the minimal volume necessary for a tone to be perceived.


 Sensation and Perception

Decoding Auditory Imagery with Multivoxel Pattern Analysis

JoVE 10267

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel—University of Southern California

Imagine the sound of a bell ringing. What is happening in the brain when we conjure up a sound like this in the "mind's ear?" There is growing evidence that the brain uses the same mechanisms for imagination that it uses for perception.1 For example, when imagining visual images, the visual cortex becomes activated, and when imagining sounds, the auditory cortex is engaged. However, to what extent are these activations of sensory cortices specific to the content of our imaginations? One technique that can help to answer this question is multivoxel pattern analysis (MPVA), in which functional brain images are analyzed using machine-learning techniques.2-3 In an MPVA experiment, we train a machine-learning algorithm to distinguish among the various patterns of activity evoked by different stimuli. For example, we might ask if imagining the sound of a bell produces different patterns of activity in auditory cortex compared with imagining the sound of a chainsaw, or the sound of a violin. If our classifier learns to tell apart the brain activity patterns produced by these three stimuli, then we can conclude that the auditory cortex is activated in a distinct


 Neuropsychology

Anesthesia Induction and Maintenance

JoVE 10263

Source: Kay Stewart, RVT, RLATG, CMAR; Valerie A. Schroeder, RVT, RLATG. University of Notre Dame, IN

The Guide for the Care and Use of Laboratory Animals ("The Guide") states that pain assessment and alleviation are integral components of the veterinary care of laboratory animals.1 The definition of anesthesia is the loss of feeling or sensation. It is a dynamic event involving changes in anesthetic depth with respect to an animal's metabolism, surgical stimulation, or variations in the external environment.


 Lab Animal Research

A Comparative Study of Drug Delivery Methods Targeted to the Mouse Inner Ear: Bullostomy Versus Transtympanic Injection

1Instituto de Investigaciones Biomédicas (IIBm) Alberto Sols CSIC-UAM, 2Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), 3Instituto de Investigación Sanitaria La Paz (IdiPAZ), 4Facultad de Veterinaria, Universidad Complutense de Madrid, 5Departmento de Otorrino laringología, Hospital Universitario La Paz

JoVE 54951


 Biology

Using Diffusion Tensor Imaging in Traumatic Brain Injury

JoVE 10276

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel—University of Southern California

Traditional brain imaging techniques using MRI are very good at visualizing the gross structures of the brain. A structural brain image made with MRI provides high contrast of the borders between gray and white matter, and information about the size and shape of brain structures. However, these images do not detail the underlying structure and integrity of white matter networks in the brain, which consist of axon bundles that interconnect local and distant brain regions. Diffusion MRI uses pulse sequences that are sensitive to the diffusion of water molecules. By measuring the direction of diffusion, it is possible to make inferences about the structure of white matter networks in the brain. Water molecules within an axon are constrained in their movements by the cell membrane; instead of randomly moving in every direction with equal probability (isotropic movement), they are more likely to move in certain directions, in parallel with the axon (anisotropic movement; Figure 1). Therefore, measures of diffusion anisotropy are thought to reflect properties of the white matter such as fiber density, axon thickness, and degree of myelination. One common measure is fractional anisotropy


 Neuropsychology

Measuring Vital Signs

JoVE 10107

Source: Meghan Fashjian, ACNP-BC, Beth Israel Deaconess Medical Center, Boston MA

The vital signs are objective measurements of a patient's clinical status. There are five commonly accepted vital signs: blood pressure, heart rate, temperature, respiratory rate, and oxygen saturation. In many practices, pain is considered the sixth vital sign and should regularly be documented in the same location as the other vital signs. However, the pain scale is a subjective measurement and, therefore, has a different value according to each individual patient. The vital signs assessment includes estimation of heart rate, blood pressure (demonstrated in a separate video), respiratory rate, temperature, oxygen saturation, and the presence and severity of pain. The accepted ranges for vital signs are: heart rate (HR), 50-80 beats per minute (bpm); respiratory rate (RR), 14-20 bpm; oxygen saturation (SaO2), > 92%; and average oral temperature, ~98.6 °F (37 °C) (average rectal and tympanic temperatures are ~1° higher, and axillary temperature is ~1° lower compared to the average oral temperature). Vital signs serve as the first clue that something may be amiss with a patient, especially if the patient is unable to communicate. Although there are


 Physical Examinations I

Diagnostic Necropsy and Tissue Harvest

JoVE 10294

Source: Kay Stewart, RVT, RLATG, CMAR; Valerie A. Schroeder, RVT, RLATG. University of Notre Dame, IN

Many animal experiments rely on final data collection time points that are gathered from the harvesting and testing of organs and tissues. The use of appropriate methods for the collection of organs and tissues can impact the quality of the samples and the analysis of the data that is gleaned for the testing of the tissues. The method of euthanasia of the animal can also impact the quality of the samples. This manuscript will outline proper necropsy techniques for rats.


 Lab Animal Research

Cranial Nerves Exam I (I-VI)

JoVE 10091

Source:Tracey A. Milligan, MD; Tamara B. Kaplan, MD; Neurology, Brigham and Women's/Massachusetts General Hospital, Boston, Massachusetts, USA

During each section of the neurological testing, the examiner uses the powers of observation to assess the patient. In some cases, cranial nerve dysfunction is readily apparent: a patient might mention a characteristic chief complaint (such as loss of smell or diplopia), or a visually evident physical sign of cranial nerve involvement, such as in facial nerve palsy. However, in many cases a patient's history doesn't directly suggest cranial nerve pathologies, as some of them (such as sixth nerve palsy) may have subtle manifestations and can only be uncovered by a careful neurological exam. Importantly, a variety of pathological conditions that are associated with alterations in mental status (such as some neurodegenerative disorders or brain lesions) can also cause cranial nerve dysfunction; therefore, any abnormal findings during a mental status exam should prompt a careful and complete neurological exam. The cranial nerve examination is applied neuroanatomy. The cranial nerves are symmetrical; therefore, while performing the examination, the examiner should compare each side to the other. A physician should approach the examination in a


 Physical Examinations III

Intra-Operative Neural Monitoring of Thyroid Surgery in a Porcine Model

1Department of Otorhinolaryngology, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, 2Department of Otorhinolaryngology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, 3Department of Otorhinolaryngology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, 4Department of Nursing, Kaohsiung Medical University Hospital, Kaohsiung Medical University, 5Department of Anesthesiology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, 6Laboratory Animal Center, Kaohsiung Medical University Hospital, Kaohsiung Medical University, 7Department of Thyroid and Parathyroid Surgery, China-Japan Union Hospital and Jilin Provincial Key Laboratory of Surgical Translational Medicine, Jilin University, 8Division of Thyroid and Parathyroid Endocrine Surgery, Department of Otolaryngology, Massachusetts Eye and Ear Infirmary; Division of Surgical Oncology, Department of Surgery, Massachusetts General Hospital; Department of Otology and Laryngology, Harvard Medical School, 9Division for Endocrine Surgery, Department of Human Pathology in Adulthood and Child-hood "G. Barresi", University Hospital G. Martino, University of Messina, 10Department of Anesthesiology, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, 11Department of Anesthesiology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University

Video Coming Soon

JoVE 57919


 JoVE In-Press

Stress Distribution During Cold Compression of Rocks and Mineral Aggregates Using Synchrotron-based X-Ray Diffraction

1Mineral Physics Institute, Department of Geoscience, Stony Brook University, 2Geological Engineering, Department of Civil and Environmental Engineering, University of Wisconsin-Madison, 3Rock and Ice Physics Laboratory, Department of Earth Sciences, University College London, 4Department of Chemistry, Stony Brook University

JoVE 57555


 Environment

The Endoscope-Assisted Minimally Invasive Retro-Sigmoid Approach (EAMIRSA): A Combination of Techniques for Improving Middle Skull Base Surgery

1Permanent Temporal Bone Dissection Laboratory, University of Perugia, 2Otolaryngology Department, Meyer Children Hospital, 3Highland Instruments, 4Otolaryngology Department, Cochlear Implant Unit, Santobono Children Hospital, 5Otolaryngology Department, Ospedale Civile of Mantua

Video Coming Soon

JoVE 58522


 JoVE In-Press

Analyzing Spatial Learning and Prosocial Behavior in Mice Using the Barnes Maze and Damsel-in-Distress Paradigms

1Department of Biology, Hampden-Sydney College, 2College of Medicine at the Medical University of South Carolina, College of South Carolina

Video Coming Soon

JoVE 58008


 JoVE In-Press

Porcine As a Training Module for Head and Neck Microvascular Reconstruction

1Department of Otolaryngology, Head and Neck Surgery, King Abdullah Medical City, 2Department of Otorhinolaryngology, Yonsei University, College of Medicine, 3Severance Biomedical Science Institute, Yonsei University, College of Medicine, 4The George W.Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 5Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University College of Medicine

JoVE 58104


 Medicine

Three-dimensional Organotypic Cultures of Vestibular and Auditory Sensory Organs

1Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of the University of Southern California, 2Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, 3Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University

JoVE 57527


 Developmental Biology

1234
More Results...