Nervous system lecture 1
... – Graded potentials Summation – combination of these graded, local potentials at the axon hillock can bring about an action potential or inhibit the generation of the action potential. – Spatial: stimulation by many neurons at one time. – Temporal: increased numbers of impulses per minute. ...
... – Graded potentials Summation – combination of these graded, local potentials at the axon hillock can bring about an action potential or inhibit the generation of the action potential. – Spatial: stimulation by many neurons at one time. – Temporal: increased numbers of impulses per minute. ...
Slideshow
... membrane has a negative charge. • As the figure shows, a Na+ / K+ pump in the cell membrane pumps sodium out of the cell and potassium into it. • However, more potassium ions leak out of the cell. Thus the inside of the membrane builds up a net negative charge relative to the outside. ...
... membrane has a negative charge. • As the figure shows, a Na+ / K+ pump in the cell membrane pumps sodium out of the cell and potassium into it. • However, more potassium ions leak out of the cell. Thus the inside of the membrane builds up a net negative charge relative to the outside. ...
Membrane structure, I
... Become limp or flaccid when lose turgor pressure Plasmolysis - plasma membrane pulls away from cell wall ...
... Become limp or flaccid when lose turgor pressure Plasmolysis - plasma membrane pulls away from cell wall ...
Nervous System PowerPoint
... When stimulated, the action potential jumped to about +40 mV. The action potential only lasted for a few milliseconds before the nerve cell returned to the resting potential. ...
... When stimulated, the action potential jumped to about +40 mV. The action potential only lasted for a few milliseconds before the nerve cell returned to the resting potential. ...
AP Biology - gwbiology
... Facilitated diffusion occurs when materials other than water are transported down a concentration gradient, spontaneously. Ion channels are a series of proteins that form channels for the materials/ions to flow through, down concentration gradients, for diffusion to occur. Gated channels are ion cha ...
... Facilitated diffusion occurs when materials other than water are transported down a concentration gradient, spontaneously. Ion channels are a series of proteins that form channels for the materials/ions to flow through, down concentration gradients, for diffusion to occur. Gated channels are ion cha ...
Nervous Tissue - Chiropractor Manhattan | Chiropractor New
... The main paths for flow of current across the membrane are ion channels. ...
... The main paths for flow of current across the membrane are ion channels. ...
Membrane structure, I
... Become limp or flaccid when lose turgor pressure Plasmolysis - plasma membrane pulls away from cell wall ...
... Become limp or flaccid when lose turgor pressure Plasmolysis - plasma membrane pulls away from cell wall ...
Chapter 48: Nervous System
... Central nervous system (CNS): nerves that integrate signals; brain and spinal cord Peripheral nervous system (PNS): nerves that carry signals btwn CNS and rest of body o Supporting Cells/Glia: structuralize nervous system and aid neuron function (more glia than neurons) Radial glia: found in d ...
... Central nervous system (CNS): nerves that integrate signals; brain and spinal cord Peripheral nervous system (PNS): nerves that carry signals btwn CNS and rest of body o Supporting Cells/Glia: structuralize nervous system and aid neuron function (more glia than neurons) Radial glia: found in d ...
Lecture 3 Review
... Once a PSP is initiated it spreads through the cytoplasm of the post-synaptic cell. For the most part, the spread of the PSP is passive; i.e. it is not conducted. Some longer dendrites have voltage-sensitive Na+/K+ channels that help the PSP along, however, this not typical. As it spreads away from ...
... Once a PSP is initiated it spreads through the cytoplasm of the post-synaptic cell. For the most part, the spread of the PSP is passive; i.e. it is not conducted. Some longer dendrites have voltage-sensitive Na+/K+ channels that help the PSP along, however, this not typical. As it spreads away from ...
Effects of Surface Modification of a Polymer Electrolyte Membrane
... Polymer electrolyte membrane fuel cell (PEMFC) is considered as a clean and efficient energy conversion device for mobile and stationary applications. Among all the components of the PEMFC, the interface between the electrolyte and electrode catalyst plays an important role in determining the cell p ...
... Polymer electrolyte membrane fuel cell (PEMFC) is considered as a clean and efficient energy conversion device for mobile and stationary applications. Among all the components of the PEMFC, the interface between the electrolyte and electrode catalyst plays an important role in determining the cell p ...
NERVOUS SYSTEMS – FUNCTION AT THE CELLULAR LEVEL
... The results of summation and integration in the dendrite/cell body region are "evaluated" at the axon hillock - if excitatory graded potential > threshold, then an action potential is initiated due to the action of electrically-gated ion channels in the axon ...
... The results of summation and integration in the dendrite/cell body region are "evaluated" at the axon hillock - if excitatory graded potential > threshold, then an action potential is initiated due to the action of electrically-gated ion channels in the axon ...
A1992HX83800001
... discovered that, in such a way, the soluble ingredients of cell interior can be washed out quite rapidly and replaced by extrinsic ones. First, we replaced potassium ions inside the cell wall with impermeable ions, switching off outward transmembrane currents; the remaining inward sodium and calcium ...
... discovered that, in such a way, the soluble ingredients of cell interior can be washed out quite rapidly and replaced by extrinsic ones. First, we replaced potassium ions inside the cell wall with impermeable ions, switching off outward transmembrane currents; the remaining inward sodium and calcium ...
Membrane potential
Membrane potential (also transmembrane potential or membrane voltage) is the difference in electric potential between the interior and the exterior of a biological cell. With respect to the exterior of the cell, typical values of membrane potential range from –40 mV to –80 mV.All animal cells are surrounded by a membrane composed of a lipid bilayer with proteins embedded in it. The membrane serves as both an insulator and a diffusion barrier to the movement of ions. Ion transporter/pump proteins actively push ions across the membrane and establish concentration gradients across the membrane, and ion channels allow ions to move across the membrane down those concentration gradients. Ion pumps and ion channels are electrically equivalent to a set of batteries and resistors inserted in the membrane, and therefore create a voltage difference between the two sides of the membrane.Virtually all eukaryotic cells (including cells from animals, plants, and fungi) maintain a non-zero transmembrane potential, usually with a negative voltage in the cell interior as compared to the cell exterior ranging from –40 mV to –80 mV. The membrane potential has two basic functions. First, it allows a cell to function as a battery, providing power to operate a variety of ""molecular devices"" embedded in the membrane. Second, in electrically excitable cells such as neurons and muscle cells, it is used for transmitting signals between different parts of a cell. Signals are generated by opening or closing of ion channels at one point in the membrane, producing a local change in the membrane potential. This change in the electric field can be quickly affected by either adjacent or more distant ion channels in the membrane. Those ion channels can then open or close as a result of the potential change, reproducing the signal.In non-excitable cells, and in excitable cells in their baseline states, the membrane potential is held at a relatively stable value, called the resting potential. For neurons, typical values of the resting potential range from –70 to –80 millivolts; that is, the interior of a cell has a negative baseline voltage of a bit less than one-tenth of a volt. The opening and closing of ion channels can induce a departure from the resting potential. This is called a depolarization if the interior voltage becomes less negative (say from –70 mV to –60 mV), or a hyperpolarization if the interior voltage becomes more negative (say from –70 mV to –80 mV). In excitable cells, a sufficiently large depolarization can evoke an action potential, in which the membrane potential changes rapidly and significantly for a short time (on the order of 1 to 100 milliseconds), often reversing its polarity. Action potentials are generated by the activation of certain voltage-gated ion channels.In neurons, the factors that influence the membrane potential are diverse. They include numerous types of ion channels, some of which are chemically gated and some of which are voltage-gated. Because voltage-gated ion channels are controlled by the membrane potential, while the membrane potential itself is influenced by these same ion channels, feedback loops that allow for complex temporal dynamics arise, including oscillations and regenerative events such as action potentials.