Nervous system
... Starting a Nerve Impulse • Depolarization – a stimulus depolarizes the neuron’s membrane • A depolarized membrane allows sodium (Na+) to flow inside the membrane • The exchange of ions initiates an action potential in the neuron Marieb, Essentials of Human Anatomy and Physiology, 8th edition, 2006 ...
... Starting a Nerve Impulse • Depolarization – a stimulus depolarizes the neuron’s membrane • A depolarized membrane allows sodium (Na+) to flow inside the membrane • The exchange of ions initiates an action potential in the neuron Marieb, Essentials of Human Anatomy and Physiology, 8th edition, 2006 ...
Chapter 6
... • stereocilium on inner hair cells – single transmembrane protein at tip that functions as a mechanically gated ion channel • stretchy protein filament (tip link) connects ion channel of one stereocilium to the sidewall of the next taller stereocilium • tallest one is bent when basilar membrane rise ...
... • stereocilium on inner hair cells – single transmembrane protein at tip that functions as a mechanically gated ion channel • stretchy protein filament (tip link) connects ion channel of one stereocilium to the sidewall of the next taller stereocilium • tallest one is bent when basilar membrane rise ...
Regulation of Action-Potential Firing in Spiny Neurons of the Rat
... FIG . 4. Comparison of action potential thresholds when evoked by long pulse, an excitatory postsynaptic potential (EPSP), or current injection adjusted to match EPSP trajectory. A: when voltage trajectory evoked by current injection is made to match the EPSP rate of rise, firing occurs at a corresp ...
... FIG . 4. Comparison of action potential thresholds when evoked by long pulse, an excitatory postsynaptic potential (EPSP), or current injection adjusted to match EPSP trajectory. A: when voltage trajectory evoked by current injection is made to match the EPSP rate of rise, firing occurs at a corresp ...
Chapter 10b
... of the middle ear, oval window create fluid which vibrate. waves within the cochlea. ...
... of the middle ear, oval window create fluid which vibrate. waves within the cochlea. ...
Systems Neuroscience Auditory system
... sounds are lateralised left versus right but seem to emanate from inside the head (not localised) ...
... sounds are lateralised left versus right but seem to emanate from inside the head (not localised) ...
notes
... Semicircular canals – fluid filled structures that provide information about dynamic equilibrium. ...
... Semicircular canals – fluid filled structures that provide information about dynamic equilibrium. ...
Physiology – Excitable Tissue – 11th May 2010
... b. Fibrous astrocytes are found predominatly in grey matter c. Protoplasmic astrocytes produce substances that are trophic to neurons d. The cell body is always at the dendritic end of the axon 43. Regarding excitation and conduction, select the true statement. a. Excitation may be caused by electri ...
... b. Fibrous astrocytes are found predominatly in grey matter c. Protoplasmic astrocytes produce substances that are trophic to neurons d. The cell body is always at the dendritic end of the axon 43. Regarding excitation and conduction, select the true statement. a. Excitation may be caused by electri ...
Biology 251 Fall 2015 1 TOPIC 7: PERIPHERAL NERVOUS SYSTEM
... Only special sense receptor that is modified endings of afferent neurons (instead of separate cell) b) Axons of olfactory receptors collectively form olfactory nerve (cranial nerve I) c) Receptor cells constantly replaced; only neurons known that do this d) 5 million receptors of 1000 different kind ...
... Only special sense receptor that is modified endings of afferent neurons (instead of separate cell) b) Axons of olfactory receptors collectively form olfactory nerve (cranial nerve I) c) Receptor cells constantly replaced; only neurons known that do this d) 5 million receptors of 1000 different kind ...
UNIT 6 NOTES Communication Between Unicellular Organisms
... membrane to reach the receptor. Signal molecules can do this by being hydrophobic or small to cross the phospholipids bilayer. Examples of ligands that can pass through the cell membrane ...
... membrane to reach the receptor. Signal molecules can do this by being hydrophobic or small to cross the phospholipids bilayer. Examples of ligands that can pass through the cell membrane ...
Action Potential Riddle Quiz
... ▫ Could be a pin prick, light, heat, sound or an electrical disturbance in another part of the neuron (“telephone call”) ▫ Electrical signal rises from changes in permeability of the neuron’s axon membranes to specific ions (Na+ & K+) ...
... ▫ Could be a pin prick, light, heat, sound or an electrical disturbance in another part of the neuron (“telephone call”) ▫ Electrical signal rises from changes in permeability of the neuron’s axon membranes to specific ions (Na+ & K+) ...
Synapse
... • It is a state of partial hyperpolarization which occurs in the postsynaptic membrane due to single presynaptic impulse ...
... • It is a state of partial hyperpolarization which occurs in the postsynaptic membrane due to single presynaptic impulse ...
E4 - Neurotransmitters and Synapses - IBDPBiology-Dnl
... binds to a receptor on a postsynaptic neuron. This sends a signal to that Cocaine interferes nerve cell, which produces a with a chemical ...
... binds to a receptor on a postsynaptic neuron. This sends a signal to that Cocaine interferes nerve cell, which produces a with a chemical ...
Axon - Cloudfront.net
... generating and propagating ACTION POTENTIALS (AP). Only cells with excitable membranes (like muscle cells and neurons) can generate APs. ...
... generating and propagating ACTION POTENTIALS (AP). Only cells with excitable membranes (like muscle cells and neurons) can generate APs. ...
chapter 43 The Nervous System
... membrane. This electrical potential then is an attractive frr'll:: pulling K+ ions back inside the cell. The balance between diffusional force -and the electrical force produces ""equilibrium potential (table 43.1). By relating the work cby each type of force, we can derive a quantitative expressz f ...
... membrane. This electrical potential then is an attractive frr'll:: pulling K+ ions back inside the cell. The balance between diffusional force -and the electrical force produces ""equilibrium potential (table 43.1). By relating the work cby each type of force, we can derive a quantitative expressz f ...
Slide 1
... • If the axon is myelinated, the action potential will “skip” from one Node of Ranvier to the next, speeding up propagation. • During an action potential, gates open in the membrane allowing Na++ ions to enter the cell, then other gates allow K+ ions to exit. • After an action potential, the axon ...
... • If the axon is myelinated, the action potential will “skip” from one Node of Ranvier to the next, speeding up propagation. • During an action potential, gates open in the membrane allowing Na++ ions to enter the cell, then other gates allow K+ ions to exit. • After an action potential, the axon ...
The Function & Anatomy of Neurons What is a Neuron?
... Motor(Efferent)- Carry impulses from the central nervous system to any part of the body capable of responding. (most are multipolar). ...
... Motor(Efferent)- Carry impulses from the central nervous system to any part of the body capable of responding. (most are multipolar). ...
The Nervous System
... Ions are electrically charged chemical molecules, e.g. K+, Na+, Cl- etc. In and around a neuron there will be positive and negative ions. When a neuron is resting it has a negative charge. This is known as its resting potential. The neuron is said the be polarised. ...
... Ions are electrically charged chemical molecules, e.g. K+, Na+, Cl- etc. In and around a neuron there will be positive and negative ions. When a neuron is resting it has a negative charge. This is known as its resting potential. The neuron is said the be polarised. ...
Chapter 28 - Montville.net
... 28.3 A neuron maintains a membrane potential across its membrane The resting potential exists because of differences in ion concentration inside and outside a cell – Inside a cell – K+ high – Na+ low ...
... 28.3 A neuron maintains a membrane potential across its membrane The resting potential exists because of differences in ion concentration inside and outside a cell – Inside a cell – K+ high – Na+ low ...
A4a - Viktor`s Notes for the Neurosurgery Resident
... minimum time for transmission across one synapse is 0.5 ms (SYNAPTIC DELAY) - time it takes for mediator to be released and to act on postsynaptic membrane. conduction along chain of neurons is slower if there are more synapses in chain. ...
... minimum time for transmission across one synapse is 0.5 ms (SYNAPTIC DELAY) - time it takes for mediator to be released and to act on postsynaptic membrane. conduction along chain of neurons is slower if there are more synapses in chain. ...
Chapter 8 & 5 powerpoint file
... Predicts membrane potential using multiple ionsresting membrane potential= the contribution of all ions that cross the membrane X membrane permeability values. Ion contribution is proportional to membrane permeability for that ion. Potentials will be affected if ion concentrations change. P=perm ...
... Predicts membrane potential using multiple ionsresting membrane potential= the contribution of all ions that cross the membrane X membrane permeability values. Ion contribution is proportional to membrane permeability for that ion. Potentials will be affected if ion concentrations change. P=perm ...
neurons
... Neurotransmitters in the synapse are reabsorbed into the sending neurons through the process of ...
... Neurotransmitters in the synapse are reabsorbed into the sending neurons through the process of ...
Resting potential
The relatively static membrane potential of quiescent cells is called the resting membrane potential (or resting voltage), as opposed to the specific dynamic electrochemical phenomena called action potential and graded membrane potential.Apart from the latter two, which occur in excitable cells (neurons, muscles, and some secretory cells in glands), membrane voltage in the majority of non-excitable cells can also undergo changes in response to environmental or intracellular stimuli. In principle, there is no difference between resting membrane potential and dynamic voltage changes like action potential from a biophysical point of view: all these phenomena are caused by specific changes in membrane permeabilities for potassium, sodium, calcium, and chloride ions, which in turn result from concerted changes in functional activity of various ion channels, ion transporters, and exchangers. Conventionally, resting membrane potential can be defined as a relatively stable, ground value of transmembrane voltage in animal and plant cells.Any voltage is a difference in electric potential between two points—for example, the separation of positive and negative electric charges on opposite sides of a resistive barrier. The typical resting membrane potential of a cell arises from the separation of potassium ions from intracellular, relatively immobile anions across the membrane of the cell. Because the membrane permeability for potassium is much higher than that for other ions (disregarding voltage-gated channels at this stage), and because of the strong chemical gradient for potassium, potassium ions flow from the cytosol into the extracellular space carrying out positive charge, until their movement is balanced by build-up of negative charge on the inner surface of the membrane. Again, because of the high relative permeability for potassium, the resulting membrane potential is almost always close to the potassium reversal potential. But in order for this process to occur, a concentration gradient of potassium ions must first be set up. This work is done by the ion pumps/transporters and/or exchangers and generally is powered by ATP.In the case of the resting membrane potential across an animal cell's plasma membrane, potassium (and sodium) gradients are established by the Na+/K+-ATPase (sodium-potassium pump) which transports 2 potassium ions inside and 3 sodium ions outside at the cost of 1 ATP molecule. In other cases, for example, a membrane potential may be established by acidification of the inside of a membranous compartment (such as the proton pump that generates membrane potential across synaptic vesicle membranes).