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The Peripheral Nervous System
The Peripheral Nervous System

... • The autonomic nervous system can be divided into the sympathetic and parasympathetic nervous systems, two branches with antagonistic actions ...
video slide
video slide

... somatosensory cortex ...
introduction to peripheral nervous system 26. 02. 2014
introduction to peripheral nervous system 26. 02. 2014

... divisions of the autonomic system carry information to the effectors. In general, these two divisions have opposing functions. The sympathetic nervous system is typically activated in stressful situations and is often referred to as the fight-or flight response. The sympathetic neurons release a neu ...
5.4 Muscle Tissues
5.4 Muscle Tissues

... – 2. Neuroglial Cells: Support and protect neurons • Parts of Neuroglial Cells: – Shwann Cells: produce myelin sheath around the PNS. – Synapse: gap between neurons ...
File
File

... A) chemical messenger that triggers muscle contractions. B) automatic response to sensory input. C) neural network. D) junction between a sending neuron and a receiving neuron. E) neural cable containing many axons. ...
Spinal cord- 2 - Weebly
Spinal cord- 2 - Weebly

... neuron in the CNS controls a lower-motor neuron in the brain stem or spinal cord. The axon of the lower-motor neuron has direct control over skeletal muscle fibers. Stimulation of the lower- motor neuron always has an excitatory effect on the skeletal muscle fibers. ...
Cardiac Qs
Cardiac Qs

... permeability to calcium and sodium ions reduces the slope of the pacemaker potential. This response is faster to occur than sympathetic stimulation. Parasympathetic fibers also innervate the atria and the AV node where it increases the AV node delay. The action potential duration itself is lengthene ...
Chapter 7
Chapter 7

... • Salty food activates a taste receptor by causing Na+ ions to move through Na+ ion channels in the cell membrane. • H+ ions in sour foods and sugar molecules in sweet foods close the K+ ion channels in receptor membranes, preventing K+ ions from leaving the cell. • In bitter foods, alkaloid compoun ...
Bolt IRM Mod 03
Bolt IRM Mod 03

... Receptor: one person who stands between the dendrite membranes with outstretched arms. ...
Nervous System III – Senses
Nervous System III – Senses

... i. Optic fibers radiate outward into the temporal lobe before reaching their destination in the visual cortex in the occipital lobe. ...
Exam - McLoon Lab
Exam - McLoon Lab

... C. A strand of mRNA is read by a ribosome and used to determine the sequence in which amino acids are linked together. D. A strand of mRNA is read by a ribosome and used to determine the sequence in which nucleotides are linked together. E. A strand of protein is read by a ribosome and used to deter ...
Composition of the Nervous System
Composition of the Nervous System

... -Schwann: found surrounding some peripheral nerve cell processes where they form the axonal myelin sheath, which improves the conduction velocity of impulses -Satellite: surround nerve cell bodies located in the ganglia of the peripheral nervous system and have functions similar to astroglia -Perine ...
REFLEX ARC A Reflex arc is the neural pathway that mediates a
REFLEX ARC A Reflex arc is the neural pathway that mediates a

... reflex actions to occur relatively quickly by activating spinal motor neurons without the delay of routing signals through the brain, although the brain will receive sensory input while the reflex action occurs. There are two types of Reflex Arc - Autonomic reflex arc affecting inner organs and Soma ...
reflex
reflex

... reflex actions to occur relatively quickly by activating spinal motor neurons without the delay of routing signals through the brain, although the brain will receive sensory input while the reflex action occurs. There are two types of Reflex Arc - Autonomic reflex arc affecting inner organs and Soma ...
The Central Nervous System
The Central Nervous System

... differ in their ionic composition, and (2) the cell membrane is selectively permeable to these ions. The membrane potential can quickly change, as the ionic permeability of the cell membrane changes, in response to chemical or physical stimuli. ...
Chapter 28 - Montville.net
Chapter 28 - Montville.net

...  A stimulus – Alters the permeability of a section of membrane – Allows ions to pass through – Changes the membrane’s voltage ...
week4am
week4am

...  Other terms – spike, firing, generating an AP ...
here - CSE IITK
here - CSE IITK

... Graded Potentials: Hyperpolarization and  Depolarization • Graded potentials are changes in membrane  potential ...
A&P Ch 8 PowerPoint(Nervous System)
A&P Ch 8 PowerPoint(Nervous System)

... differ in their ionic composition, and (2) the cell membrane is selectively permeable to these ions. The membrane potential can quickly change, as the ionic permeability of the cell membrane changes, in response to chemical or physical stimuli. ...
6.1 The Nervous System - Blyth-Exercise
6.1 The Nervous System - Blyth-Exercise

... causes the quadriceps to contract, reciprocal inhibition causes the antagonist (opposing) muscle group (hamstrings in this case) to relax • Makes it easier for the quadriceps to contract • Allows constant adjustment between the two muscle groups ...
the pain process
the pain process

... Pain involves an incredibly complicated myriad of physiochemical responses leading to the perception of an unpleasant sensation arising from actual or potential tissue damage. While the full complexities of the pain process are beyond the scope of this discussion, an understanding of the terminology ...
Spinal Cord
Spinal Cord

... sensory neurons towards the brain, and higher brain centers to motor neurons • Modulates neural activity within motor systems. • Are also involved in reflexes. ...
Primary motor cortex (M1)
Primary motor cortex (M1)

... • Internal models adapt when there is a discrepancy between expected and actual sensory feedback. • In amputation, internal models must adapt in response to very large errors. ...
Motor functions
Motor functions

... of corticospinal tracts, the paralysis and weakness affects all muscles below a given level. • C1-C4 – central lesion of UE and LE • C5-Th2 – peripheral lesion UE, central LE • Th2-Th11 – central lesion of LE • Th12-L3 – peripheral lesion of LE • In bilateral spinal cord lesion, the bladder and bowe ...
Spinal Nerves
Spinal Nerves

... Common fibular Tibial Sural (cut) Deep fibular Superficial fibular Plantar branches (b) Distribution of the major nerves from the sacral plexus to the lower limb Copyright © 2010 Pearson Education, Inc. ...
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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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