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Chapter 11 ppt A
Chapter 11 ppt A

... – Formerly called nodes of Ranvier ...
Spinal Cord, Spinal Nerves, and the Autonomic Nervous System
Spinal Cord, Spinal Nerves, and the Autonomic Nervous System

... cord transection in an auto accident). The muscle receives no stimulation; thus, it becomes flaccid and atrophies. Spastic paralysis occurs as a result of upper motor neuron damage (e.g. from brain hemorrhage). Voluntary motor activity is lost, but reflex movements initiated by spinal cord neurons s ...
Neural pathways
Neural pathways

... ◦ Each branch may synapse with several CN (‘second order’) neurons ◦ Each CN neuron may receive information from one or more primary neurons ...
The Ear
The Ear

... Tip-links –Hair Bundle Motor ...
Open Document - Clinton Community College
Open Document - Clinton Community College

... Neuron at rest: ◦ Slightly negative charge ◦ Contains ions flowing back and forth ...
Examination of sensory physiology Obgective:To determine the
Examination of sensory physiology Obgective:To determine the

... nervous system via large myelinated peripheral nerve fibers through posterior column pathway ,while nociceptive (pain and temperature ) modalities enter via small, myelinated OR unmyelinated fibers such as pain and temperature through spinothalamic pathway Term in sensation : 1.Hyposthesia :decrease ...
Chapter 8
Chapter 8

...  Ballistic movement - A habitual, rapid, wellpracticed movement that does not depend on sensory feedback; controlled by the cerebellum. ...
The Autonomic Nervous System and Visceral Reflexes
The Autonomic Nervous System and Visceral Reflexes

... emotions of stress, anger, fear ...
Motor Units (cont`d)
Motor Units (cont`d)

... Copyright © 2012 American College of Sports Medicine ...
Sensation_and_Perception
Sensation_and_Perception

... Energy detected is physical pressure on tissue. Many nerve endings in the skin act as touch receptors. Touch is both an active and passive sense. Changes in touch provide most important sensory information. ...
Done by : Noor Bjant.hala Dr: loai zghol
Done by : Noor Bjant.hala Dr: loai zghol

... This graded potential can indicate the intensity of the stimulus, while at the hillock and at nodes of ranvier the potential is action potential because there're voltage gated ion channels. Note : When the receptor potential rises above the threshold, action potentials appear and the receptor is act ...
abstract - ELSC at
abstract - ELSC at

... Turbulent Relationships – Single Cell Dynamics and the Decay of Information in Balanced Neuronal Circuits Neuronal circuits in the central nervous system process information by the collective dynamics of large recurrently connected networks of nerve cells interacting with each other by sending and r ...
Brain Stem Reticular Formation
Brain Stem Reticular Formation

...  Includes only fibers for torso, arms, legs (i.e., headless HAL)  Decussates at a single point in the pyramids of the medulla (pyramidal decussation) ...
but all of the same type
but all of the same type

... hears someone else do the same (V+S), when he only sees it (V), and when he only hears it (S) below-right: a neuron in premotor cortex fires when an object is grasped even if the object is hidden by a screen (but known to be in place) ...
Electrophysiology of Brachial and Lumbosacral Plexopathies
Electrophysiology of Brachial and Lumbosacral Plexopathies

... mild conduction slowing (due to loss of fast conducting axons) may be observed when axonal loss is significant. Side-to-side comparisons of amplitude are sometimes useful in demonstrating more subtle abnormalities, with a 50% reduction compared to the uninvolved side considered abnormal. MNCS are im ...
EEG - Wayne State University
EEG - Wayne State University

... i. Prolonged latency/absent F-wave indicates proximal slowing, seen w/ radiculopathies, spinal processes, Guillen Barre 2. Electromyography (used to distinguish btw neuropathies/myopathies) a. Fibrillation: pathological, indicates denervation in either case b. Amplitude: i. Neuropathy = large, indic ...
Introduction to Neuroscience: Systems Neuroscience – Concepts
Introduction to Neuroscience: Systems Neuroscience – Concepts

... spatial-frequency + temporal-frequency (velocity) + direction of the grating. Æ A technical (but important) corollary of this is that the “best stimulus” of a neuron may therefore be difficult, or even impossible to find, even if you try running your experiment following some gradient-ascent optimiz ...
Reflexes. Reaction time.
Reflexes. Reaction time.

... one motor neuron; monosynaptic refers to the presence of a single chemical synapse) – peripheral muscle reflexes (patellar reflex, achilles reflex): brief stimulation to the muscle spindle results in contraction of the muscle – high conduction velocity, short latency, without extension (i.e. no irra ...
Shier, Butler, and Lewis: Hole`s Human Anatomy and Physiology
Shier, Butler, and Lewis: Hole`s Human Anatomy and Physiology

... a. Pain receptors can be stimulated by damaged tissue. b. Pain receptors adapt very little, if at all. 3. Visceral Pain a. Visceral pain receptors respond differently to stimulation than those of surface tissues. b. Pain in visceral organs result from stimulation of mechanoreceptors and from decreas ...
Perception - Department of Psychology
Perception - Department of Psychology

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Document
Document

... primary motor cortex • When stimulated, muscles on the opposite side of the body contract. • Has complete representation of body’s musculature. • Greater space for fine motor control than for less precise motor control • Very focal stimulation --> organized movement (excitation and inhibition) Wed. ...
05. Motor Pathways 2011.jnt
05. Motor Pathways 2011.jnt

... Most corticospinal lesions are in the internal capsule or cerebral cortex in the distribution of the middle cerebral artery and result in classic signs. When the tract is lesioned in the brain stem these signs are associated with cranial nerve signs A. ...
FIGURE LEGENDS FIGURE 35.1 Functional organization of the
FIGURE LEGENDS FIGURE 35.1 Functional organization of the

... exhibits respiratory long-term facilitation. Peak electrical activity in the phrenic nerve corresponds to the magnitude of inspiration. When arterial O2 and CO2 are normal (prehypoxia), the phrenic bursts are rhythmic and consistent (shown with expanded time scale). Upon exposure to intermittent (up ...
Reflexes and Brain - Sinoe Medical Association
Reflexes and Brain - Sinoe Medical Association

... perception of pain in response to potentially damaging stimulus. Nociceptors are the nerve endings responsible for nociception, one of the two types of persistent pain (the other, neuropathic pain, occurs when nerves in the central or peripheral nervous system are damaged). When they are activated, ...
Glossary of Neuroanatomical Terms and Eponyms
Glossary of Neuroanatomical Terms and Eponyms

... Amygdala. L. amygdalum, from Gr. amygdale, almond. Amygdala or amygdaloid body in the temporal lobe of the cerebral hemisphere. Aneurysm. Gr. aneurysma, dilation or widening. An abnormal widening of an artery. It can compress nearby structures and may burst. Anopsia. an, neg. + Gr. opsis, vision. De ...
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Rheobase



Rheobase is a measure of membrane excitability. In neuroscience, rheobase is the minimal current amplitude of infinite duration (in a practical sense, about 300 milliseconds) that results in the depolarization threshold of the cell membranes being reached, such as an action potential or the contraction of a muscle. In Greek, the root ""rhe"" translates to current or flow, and ""basi"" means bottom or foundation: thus the rheobase is the minimum current that will produce an action potential or muscle contraction.Rheobase can be best understood in the context of the strength-duration relationship (Fig. 1). The ease with which a membrane can be stimulated depends on two variables: the strength of the stimulus, and the duration for which the stimulus is applied. These variables are inversely related: as the strength of the applied current increases, the time required to stimulate the membrane decreases (and vice versa) to maintain a constant effect. Mathematically, rheobase is equivalent to half the current that needs to be applied for the duration of chronaxie, which is a strength-duration time constant that corresponds to the duration of time that elicits a response when the nerve is stimulated at twice rheobasic strength.The strength-duration curve was first discovered by G. Weiss in 1901, but it was not until 1909 that Louis Lapicque coined the term ""rheobase"". Many studies are being conducted in relation to rheobase values and the dynamic changes throughout maturation and between different nerve fibers. In the past strength-duration curves and rheobase determinations were used to assess nerve injury; today, they play a role in clinical identification of many neurological pathologies, including as Diabetic neuropathy, CIDP, Machado-Joseph Disease, and ALS.
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