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THE CENTRAL NERVOUS SYSTEM
THE CENTRAL NERVOUS SYSTEM

... one another. In a synapse, the neuron that sends the signal is the presynaptic neuron and the target cell receives that signal is the postsynaptic neuron or cell. Synapses can be either electrical or chemical. Electrical synapses are characterized by the formation of gap junctions that allow ions an ...
Review of Thoracic and Abdominal Autonomics
Review of Thoracic and Abdominal Autonomics

... The presynaptic fibers run from the spinal cord into the sympathetic chain, a line of paravertebral (= adjacent to the vertebrae) ganglia connected by vertical pathways— the sympathetic trunk. White rami communicantes connect the sympathetic chain to the spinal nerves—axons pass through these rami ...
Stimulus Response Time Lab
Stimulus Response Time Lab

... Sensory neurons of the PNS carry information to the CNS. Signals from the brain are carried to motor neurons (PNS), which carry out responses by muscles. In this lab, you will be comparing the rate at which sensory neurons, working through the brain, can elicit responses via motor neurons. Purpose: ...
Diabetic Peripheral Neuropathy - Remarkable Podiatrist at Foot
Diabetic Peripheral Neuropathy - Remarkable Podiatrist at Foot

... o Motor nerves, which control the muscles and give them their strength and tone o Autonomic nerves, which allow the body to perform certain involuntary functions, such as sweating Diabetic peripheral neuropathy doesn’t emerge overnight-instead, it usually develops slowly and worsens over time. Some ...
M555 Medical Neuroscience
M555 Medical Neuroscience

... All of the brain stem sections are taken from one human brain. They were cut 40 microns thick and the interval between the sections is about l mm. The sections are stained with Luxol fast blue and counterstained with cresyl violet. In general, white mater appears darker (bluer) than gray matter on ...
glossary of terms
glossary of terms

... Kinesphere  (reach  space):     “the  sphere  around  the  body  whose  periphery  can  be  reached  by  easily  extended   limbs  without  stepping  away  from  that  place  which  is  the  point  of  support  when   standing  on  on ...
Bio 12 - Test Review..
Bio 12 - Test Review..

... of a neuron. An action potential travel down the axon toward the terminal where it causes neurotransmitter to be released which bind to receptors on the following dendrite (post synaptic membrane) and a new action potential to be created. Cannot reverse this because dendrites do not ...
important ascending tracts
important ascending tracts

... The corticospinal tract is involved in voluntary movement. The majority of fibres of the corticospinal tract cross over in the medulla, resulting in muscles being controlled by the opposite side of the brain. The pyramidal tracts are named because they pass through the pyramids of the medulla. ...
Somatosensory System
Somatosensory System

... Posterior Columns. We can feel the position of our limbs and sense the degree of muscle tension in them. We can feel the weight of the body resting on our soles (i.e., we “feel the ground under our feet”). We can also perceive motion in the joints. Thus, at least some proprioceptive impulses must re ...
Schwann cells
Schwann cells

... 1. Consists of nerves extending from brain and spinal cord a. cranial nerves (off the brain) b. spinal nerves (off the spinal cord) 2. Peripheral nerves link all regions of the body to the CNS 3. Nucleus – group of nerve cell bodies in the brain/cord 4. Ganglion – group of nerve cell bodies outside ...
15. Nervous System: Autonomic Nervous System
15. Nervous System: Autonomic Nervous System

... skeletal muscle, it simply sends commands through somatic motor neurons, which stimulate contraction of the particular skeletal muscle. See Figure 15.1 for an overview. Somatic motor neurons can be activated consciously. However, they can also be activated unconsciously to maintain posture, breathe, ...
LPN-C
LPN-C

... The SNS • consists of sensory neurons from the head, body wall, extremities, and motor neurons to skeletal muscle. • The motor responses are under conscious control and therefore the SNS is voluntary. • Certain peripheral nerves perform specialized functions and form the autonomic nervous system; t ...
Lecture 5 Transmitters and receptors lecture 2015
Lecture 5 Transmitters and receptors lecture 2015

... Kainate: Kainic acid ...
successful transplantation of motoneurons into the peripheral nerve
successful transplantation of motoneurons into the peripheral nerve

... restore functional muscle activity, when combined with computer-programmed functional electrical stimulation (FES). The number of MNs required to restore innervation to denervated muscles in adult Fischer 344 rats was investigated by comparing two groups, one transplanted with 2 × 105 cells (group A ...
PPTX - Bonham Chemistry
PPTX - Bonham Chemistry

... Hormone: A chemical messenger released by an endocrine gland into the bloodstream and transported therein to reach its target cell. The distinction between a neurotransmitter and a hormone is physiological, not chemical. It depends on whether the molecule acts over a short distance (across a synapse ...
Muscle Twitches - Mount Carmel Academy
Muscle Twitches - Mount Carmel Academy

... Nerve impulses are delivered to the muscle at a very rapid rate – so rapid that the cells do not get a chance to relax completely between stimuli.  As a result, the effects of the successive contractions are “summed” (added) together, and the contraction of the muscle get stronger and ...
Muscles - Part 3
Muscles - Part 3

... Nerve impulses are delivered to the muscle at a very rapid rate – so rapid that the cells do not get a chance to relax completely between stimuli.  As a result, the effects of the successive contractions are “summed” (added) together, and the contraction of the muscle get stronger and ...
THE PNS
THE PNS

... peripheral axons enclosed by connective tissue  Connective tissue coverings include:  Endoneurium – loose connective tissue that surrounds axons  Perineurium – coarse connective tissue that bundles fibers into fascicles  Epineurium – tough fibrous sheath around a nerve Copyright © 2004 Pearson E ...
Neuroscience Journal Club
Neuroscience Journal Club

... Principal whisker response was smaller than in control animals but the surround was stronger and broader Sensory deprivation has a profound effect on the TUNING of sensory maps of layer 2/3 pyramidal neurons. ...
Slide 1
Slide 1

... Discharge of large capacitive currents (5-10kA, 2-300us) through a coil producing high magnetic field (1-2T). Stimulus site depends on coil design, coil orientation and stimulus intensity ...
The Dancing Cockroach Leg
The Dancing Cockroach Leg

... The woman is singing in a higher pitch (high frequency, low amplitude waves), which is not sufficient to bring the motor neuron to threshold and cause the motor neuron to fire an action potential. 4) What do you think would happen if you increased the volume of the song? The cockroach leg may move m ...
Peripheral nerve compression
Peripheral nerve compression

... • Compression of the PIN with pain only (no motor or sensory symptoms) • Presents with deep aching pain in dorsoradial proximal forearm , increases during rotation and lifting • Tender over extensors distal to lateral epicondyle, pain at radial tunnel with resisted middle finger extension, resisted ...
Pathologies of the Elbow
Pathologies of the Elbow

... ligament and of 2 heads of FCU  Elbow flexion tightens arch  Repeated rapid activities such as throwing and prolonged flexion may traction or compress nerve  Nerve can sublux out of tunnel ...
Document
Document

... • the axons surrounded by endoneurium • Each individual axon may or may not be ...
8.7 Learning and Memory
8.7 Learning and Memory

... • Two neurons are involved in habituation- the Ca2+ channels in the pre-synaptic neuron become less responsive- less Ca uptake. • In sensitisation three neurones are involvedSerotonin released by neurones from the receptor of the first stimulus increase the uptake of Ca in the pre-synaptic neuron of ...
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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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