1. Dominant Optic Atrophy (DOA): Clinical, genetic and
... Mutations in the Kv1.1 subunit of the axonal potassium channel result in Episodic Ataxia Type 1, which is characterised by brief episodes of cerebellar dysfunction, persistent neuromyotonia and increased incidence of epilepsy. Ten subjects from 5 kindreds with EA1 underwent neurophysiological evalua ...
... Mutations in the Kv1.1 subunit of the axonal potassium channel result in Episodic Ataxia Type 1, which is characterised by brief episodes of cerebellar dysfunction, persistent neuromyotonia and increased incidence of epilepsy. Ten subjects from 5 kindreds with EA1 underwent neurophysiological evalua ...
7. Describe what membrane potential is, and how
... blood-brain barrier? • This restricts the passage of most substances into the brain • Allows the chemical environment of the CNS to be well controlled ...
... blood-brain barrier? • This restricts the passage of most substances into the brain • Allows the chemical environment of the CNS to be well controlled ...
presentation source
... • In un-myelinated nerves the action potential propagates continously along the axons by sequentially activating populations of Na+ channels in adjoining segments of axon ...
... • In un-myelinated nerves the action potential propagates continously along the axons by sequentially activating populations of Na+ channels in adjoining segments of axon ...
HONORS BIOLOGY Chapter 28 Nervous Systems
... Synapses are junctions where signals are transmitted between Two neurons or between neurons and effector cells Electrical synapses ...
... Synapses are junctions where signals are transmitted between Two neurons or between neurons and effector cells Electrical synapses ...
The vocabulary of nerve cells
... • All the information then is coded as the frequency of action potentials, not their amplitude. – The range of intensity of the stimulus must thus be coded into the possible range of frequencies of a neuron. The minimum detectable change in frequency depends on the constancy of firing of the signali ...
... • All the information then is coded as the frequency of action potentials, not their amplitude. – The range of intensity of the stimulus must thus be coded into the possible range of frequencies of a neuron. The minimum detectable change in frequency depends on the constancy of firing of the signali ...
Neuron Physiology Notes
... _________________________- Ions move from high concentration to a low concentration passively ______________ pumps moves ions actively using ATP Active Pump ...
... _________________________- Ions move from high concentration to a low concentration passively ______________ pumps moves ions actively using ATP Active Pump ...
The Peripheral Nervous System The P.N.S.
... Consequences of Damage to Nerve Cells A. The nerve does not ___________________ B. The transmission of impulses may _______ ___________________________________ ___________________________________ C. Interpretation of the impulse may be ___________________________________ __________________________ ...
... Consequences of Damage to Nerve Cells A. The nerve does not ___________________ B. The transmission of impulses may _______ ___________________________________ ___________________________________ C. Interpretation of the impulse may be ___________________________________ __________________________ ...
MOTOR NEURON DISEASE
... similar clinical features and CSF change and pathological abnormalities of multifocal with nerve conduction features reflecting demyelination. to GBS The major differences between the two conditions are in the time course and their response to corticosteroids Prednisone, plasmapheresis, and IVIg Mul ...
... similar clinical features and CSF change and pathological abnormalities of multifocal with nerve conduction features reflecting demyelination. to GBS The major differences between the two conditions are in the time course and their response to corticosteroids Prednisone, plasmapheresis, and IVIg Mul ...
Worksheet for Nervous Systems
... 31. If a sufficiently strong stimulus causes depolarization to reach “threshold potential” it triggers a different type of response called an _ ________. ...
... 31. If a sufficiently strong stimulus causes depolarization to reach “threshold potential” it triggers a different type of response called an _ ________. ...
BOX 5.2 GOLDMAN-HODGKIN-KATZ EQUATION An equation
... are pK : pNa : pCl =1:00 : 0:04 : 0:45: The membrane of the squid giant axon, at rest, is most permeable to K+ ions, less so to Cl−, and least permeable to Na+. (Chloride appears to contribute considerably less to the determination of the resting potential of mammalian neurons.) These results indica ...
... are pK : pNa : pCl =1:00 : 0:04 : 0:45: The membrane of the squid giant axon, at rest, is most permeable to K+ ions, less so to Cl−, and least permeable to Na+. (Chloride appears to contribute considerably less to the determination of the resting potential of mammalian neurons.) These results indica ...
Anatomy and Physiology 241 Lecture Objectives The Nervous
... important in nerve conduction? Be sure you know how and why it is maintained. What does electrochemical gradient mean? Know how it is maintained by the Na-K ATPase pump. Describe the changes that happen to a neuron cell membrane when an appropriate stimulus is applied to it. Define local potential a ...
... important in nerve conduction? Be sure you know how and why it is maintained. What does electrochemical gradient mean? Know how it is maintained by the Na-K ATPase pump. Describe the changes that happen to a neuron cell membrane when an appropriate stimulus is applied to it. Define local potential a ...
13. Electrochemical Impulse
... Electrochemical Impulse It has long been known that electrical impulses are present in living organisms, but it is only within the last century that we have understood how and why neurons transmit electricity These impulses are generated using uneven concentrations of ions inside the neuron compared ...
... Electrochemical Impulse It has long been known that electrical impulses are present in living organisms, but it is only within the last century that we have understood how and why neurons transmit electricity These impulses are generated using uneven concentrations of ions inside the neuron compared ...
Fact sheet (PDF, 63.03 KB) (opens in a new window)
... which traditionally have been some of the most challenging cases for surgeons. Nervous injury, from trauma, disease or otherwise, is a major medical problem. Mature neurons do not undergo cell division and therefore it is very difficult to achieve successful rehabilitation after nerve injuries. It i ...
... which traditionally have been some of the most challenging cases for surgeons. Nervous injury, from trauma, disease or otherwise, is a major medical problem. Mature neurons do not undergo cell division and therefore it is very difficult to achieve successful rehabilitation after nerve injuries. It i ...
The Importance of the Nervous System
... • from the peak of an action potential until the membrane reaches resting potential again • a few milliseconds • ensures action potential travels in one direction only ...
... • from the peak of an action potential until the membrane reaches resting potential again • a few milliseconds • ensures action potential travels in one direction only ...
Chapter 24
... carry an impulse from the CNS to a sense organ. carry a nerve impulse from a sense organ to the CNS. carry a nerve impulse to a muscle. carry a nerve impulse both to and from a sense organ. ...
... carry an impulse from the CNS to a sense organ. carry a nerve impulse from a sense organ to the CNS. carry a nerve impulse to a muscle. carry a nerve impulse both to and from a sense organ. ...
Nerve
... mEq/L -Na channels are inactive at rest, voltage gated, K the Oligodendrocytes: membrane potential Myelinating ...
... mEq/L -Na channels are inactive at rest, voltage gated, K the Oligodendrocytes: membrane potential Myelinating ...
Chapter 48: Nervous System
... o Depolarization: a decrease in the electrical gradient (i.e., membrane potential increases toward 0 mV) Na+ channels allow sodium to flow into the cell, making it more positive o Action potential: nerve impulse that is triggered if the depolarization reaches a certain level, known as the threshol ...
... o Depolarization: a decrease in the electrical gradient (i.e., membrane potential increases toward 0 mV) Na+ channels allow sodium to flow into the cell, making it more positive o Action potential: nerve impulse that is triggered if the depolarization reaches a certain level, known as the threshol ...
File - Dr. Jerry Cronin
... to the primary auditory cortex in the temporal lobe. Slight differences in the timing of nerve impulses arriving from the two ears at the superior olivary nuclei in the pons allow us to locate the source of a sound ...
... to the primary auditory cortex in the temporal lobe. Slight differences in the timing of nerve impulses arriving from the two ears at the superior olivary nuclei in the pons allow us to locate the source of a sound ...
Chapter 11 Worksheet 2 The action potential: Fill in the blanks. The
... These molecules bind to receptors that act as ______________ gated ion channels. When these channels open they allow ions to flow in or out which produces small changes in the membrane around the receptors, known as ______________________________. These changes can be positive/______________________ ...
... These molecules bind to receptors that act as ______________ gated ion channels. When these channels open they allow ions to flow in or out which produces small changes in the membrane around the receptors, known as ______________________________. These changes can be positive/______________________ ...
9.2 - 4ubiology
... [4] Na+ channels close and K+ gated channels now open [5] K+ ions diffuse out of the neurone down the electrochemical diffusion gradient, so making the inside of the neuron less positive (= more negative) again: this is repolarization and the neuron has become repolarized ...
... [4] Na+ channels close and K+ gated channels now open [5] K+ ions diffuse out of the neurone down the electrochemical diffusion gradient, so making the inside of the neuron less positive (= more negative) again: this is repolarization and the neuron has become repolarized ...
Tayler
... Threshold – the critical level to which membrane potential must be depolarized in order to initiate an action potential Polarization of the neuron’s membrane: Sodium is on the outside and potassium is on the inside Resting potential gives the neuron a break Action potential: Sodium ions move ...
... Threshold – the critical level to which membrane potential must be depolarized in order to initiate an action potential Polarization of the neuron’s membrane: Sodium is on the outside and potassium is on the inside Resting potential gives the neuron a break Action potential: Sodium ions move ...
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.