slides - Smith Lab
... • Part of the inward Na+ current flows down to interior of axon to produce local potential in advance of an action potential • Local potential depolarizes the membrane • Activated voltage-gated Na+ channels • When reach threshold, inward current further depolarizes the membrane and acts as a source ...
... • Part of the inward Na+ current flows down to interior of axon to produce local potential in advance of an action potential • Local potential depolarizes the membrane • Activated voltage-gated Na+ channels • When reach threshold, inward current further depolarizes the membrane and acts as a source ...
Membrane potential (mV)
... Stimulation causes active gated channel to open and Na+ goes in until… Threshold- all Na+ open quickly rises to peak Peak- Na+ gated close, K+ gated open to let K+ out Hyperpolarization- gates close and the pumps take over to reach resting potential again. ...
... Stimulation causes active gated channel to open and Na+ goes in until… Threshold- all Na+ open quickly rises to peak Peak- Na+ gated close, K+ gated open to let K+ out Hyperpolarization- gates close and the pumps take over to reach resting potential again. ...
The Nerve Impulse - hrsbstaff.ednet.ns.ca
... he passage of impulses from motor neurons to muscles occur at special points of contact called neuromuscular junctions. The motor end plates contain synaptic vesicles which release acetylcholine which combine with receptors molecules on the muscle cell membrane, thus sending an impulse to the mu ...
... he passage of impulses from motor neurons to muscles occur at special points of contact called neuromuscular junctions. The motor end plates contain synaptic vesicles which release acetylcholine which combine with receptors molecules on the muscle cell membrane, thus sending an impulse to the mu ...
The Nervous System
... How does the nerve re-set itself? • After firing a neuron has to re-set itself – Na+ needs to move back out – K+ needs to move back in – both are moving against concentration gradients • need a pump!! ...
... How does the nerve re-set itself? • After firing a neuron has to re-set itself – Na+ needs to move back out – K+ needs to move back in – both are moving against concentration gradients • need a pump!! ...
Nervous System: Nervous Tissue (Chapter 12) Lecture Materials for
... out) and negative charge inside (proteins)! ...
... out) and negative charge inside (proteins)! ...
Nervous System
... signals away from the cell body. It is the output cable – Dendrite: Fibers called dendrites receive signals and carry them toward the cell body ...
... signals away from the cell body. It is the output cable – Dendrite: Fibers called dendrites receive signals and carry them toward the cell body ...
Nervous System
... Myelin sheath - A spiral membrane that surrounds the axon of some neurons. The membrane is composed of fatty (lipoprotein) membranes. There is an analogy with the insulation of electrical wires. In the PNS This sheath is produced by glial cells called Schwann cells. Neurons whose axons are myelinate ...
... Myelin sheath - A spiral membrane that surrounds the axon of some neurons. The membrane is composed of fatty (lipoprotein) membranes. There is an analogy with the insulation of electrical wires. In the PNS This sheath is produced by glial cells called Schwann cells. Neurons whose axons are myelinate ...
Neuron Structure and Function
... 2. Loss of current (charge) due to capacitance properties of the membrane cell membrane acts as a capacitor 2 conducting sheets separated by an insulating material - the closer the sheets the better the capacitor lipid bilayer is 7 nm thick therefore = excellent capacitor it takes time and c ...
... 2. Loss of current (charge) due to capacitance properties of the membrane cell membrane acts as a capacitor 2 conducting sheets separated by an insulating material - the closer the sheets the better the capacitor lipid bilayer is 7 nm thick therefore = excellent capacitor it takes time and c ...
Lab 2 slides
... » Homework is due Friday, Feb 10 » This homework has more projects than the last, but fewer questions per project ...
... » Homework is due Friday, Feb 10 » This homework has more projects than the last, but fewer questions per project ...
Lectures 26-27 Study Guide
... sodium inflow. Most voltage-gated potassium channels open, permitting potassium outflow, making the inside of the cell negative again (cell is trying to get back to its normal membrane potential and it’s doing this be adding in back the negative “charge”) e. Undershoot: The voltage-gated sodium chan ...
... sodium inflow. Most voltage-gated potassium channels open, permitting potassium outflow, making the inside of the cell negative again (cell is trying to get back to its normal membrane potential and it’s doing this be adding in back the negative “charge”) e. Undershoot: The voltage-gated sodium chan ...
CHAPTER 48 NEURONS, SYNAPSES, AND SIGNALING I. Student
... Becomes more negative c. Remains unchanged ...
... Becomes more negative c. Remains unchanged ...
Nervous Tissue
... • Neurons are electrically excitable due to the voltage difference across their membrane • Communicate with 2 types of electric signals – action potentials that can travel long distances – graded potentials that are local membrane changes only ...
... • Neurons are electrically excitable due to the voltage difference across their membrane • Communicate with 2 types of electric signals – action potentials that can travel long distances – graded potentials that are local membrane changes only ...
CHAPTER NINE: THE NERVOUS SYSTEM
... of a specific neurotransmitter ii. ________-gated channelsopen and close in response to changes in membrane potentials iii. Mechanically gated channelopen and close in response to physical deformation of receptors b. When gated channels are _______ i. Ions diffuse quickly across the membrane along t ...
... of a specific neurotransmitter ii. ________-gated channelsopen and close in response to changes in membrane potentials iii. Mechanically gated channelopen and close in response to physical deformation of receptors b. When gated channels are _______ i. Ions diffuse quickly across the membrane along t ...
Neural Tissue – Chapter 12
... This is called local current. (As sodium ions move into the cell, other sodium ions fill in the gaps.) This causes adjacent portions of the cell membrane to become depolarized. The degree of depolarization decreases with distance away from the stimulation site and because some of the sodium ions mov ...
... This is called local current. (As sodium ions move into the cell, other sodium ions fill in the gaps.) This causes adjacent portions of the cell membrane to become depolarized. The degree of depolarization decreases with distance away from the stimulation site and because some of the sodium ions mov ...
Overview Functions of the Nervous System
... • 1. Action potential arrives at axon terminal. • 2. Voltage-gated Ca2+ channels open and Ca2+ enters the axon terminal • 3. Ca2+ entry causes neurotransmitter-containing vesicles to release their contents by exocytosis • 4. Neurotransmitter diffuses across the synaptic cleft and binds to specific r ...
... • 1. Action potential arrives at axon terminal. • 2. Voltage-gated Ca2+ channels open and Ca2+ enters the axon terminal • 3. Ca2+ entry causes neurotransmitter-containing vesicles to release their contents by exocytosis • 4. Neurotransmitter diffuses across the synaptic cleft and binds to specific r ...
Week 2 Lecture Notes
... contains a salt solution resembling the fluid normally found within the cell, is lowered to the cell membrane where a tight seal is formed. When a little suction is applied to the pipette, the "patch" of membrane within the pipette ruptures, permitting access to the whole cell. The electrode, which ...
... contains a salt solution resembling the fluid normally found within the cell, is lowered to the cell membrane where a tight seal is formed. When a little suction is applied to the pipette, the "patch" of membrane within the pipette ruptures, permitting access to the whole cell. The electrode, which ...
Slide 1
... potential is negative to EK when gK is increased, then K+ ions will enter the cell, therefore making the inside more positive (more depolarized). If the membrane potential is exactly EK when gK is increased, then there will be no net movement of K+ ions. (B) Opening K+ channels when the membrane pot ...
... potential is negative to EK when gK is increased, then K+ ions will enter the cell, therefore making the inside more positive (more depolarized). If the membrane potential is exactly EK when gK is increased, then there will be no net movement of K+ ions. (B) Opening K+ channels when the membrane pot ...
Biology 212: January 30, 2002
... Potassium (K+) ions leave the cell along their chemical gradient because the membrane is relatively permeable to it. Since potassium is positively charged, the result is that the inside is negative. It would be even more negative (about -85 mV is where K+ chemical gradient matches the electrical g ...
... Potassium (K+) ions leave the cell along their chemical gradient because the membrane is relatively permeable to it. Since potassium is positively charged, the result is that the inside is negative. It would be even more negative (about -85 mV is where K+ chemical gradient matches the electrical g ...
AP Biology Animal Form and Function
... 3. Repolarization—In response to the inflow of Na+, another kind of gated channel opens, this time allowing the K+ on the inside to rush out of the cell. The movement of K+ out of the cell causes repolarization by restoring the original membrane polarization (a condition where it is once again more ...
... 3. Repolarization—In response to the inflow of Na+, another kind of gated channel opens, this time allowing the K+ on the inside to rush out of the cell. The movement of K+ out of the cell causes repolarization by restoring the original membrane polarization (a condition where it is once again more ...
Passive Cable Properties of Axons
... • In contrast to the internal axial resistance (ri) which is relatively high because of the small dimensions of most nerve processes, the external medium has a relatively low resistivity for current because of its relatively large volume. For this reason the resistivity of the paths either along a p ...
... • In contrast to the internal axial resistance (ri) which is relatively high because of the small dimensions of most nerve processes, the external medium has a relatively low resistivity for current because of its relatively large volume. For this reason the resistivity of the paths either along a p ...
Chapter 3
... – graded potentials participate in localized cellular communication – action potentials can communicate a signal over long or short distances • The difference in voltage across a membrane is referred to as the membrane potential – resting membrane potential is the voltage difference that exists when ...
... – graded potentials participate in localized cellular communication – action potentials can communicate a signal over long or short distances • The difference in voltage across a membrane is referred to as the membrane potential – resting membrane potential is the voltage difference that exists when ...
file
... Giving a patient Lithium adds even more positive ions on the outside of the nerve cell which raises the resting potential, thus making it easier to initiate an action potential (ions are even less in balance thus easier to get action potential going). The effect often makes the person more active an ...
... Giving a patient Lithium adds even more positive ions on the outside of the nerve cell which raises the resting potential, thus making it easier to initiate an action potential (ions are even less in balance thus easier to get action potential going). The effect often makes the person more active an ...
somatic sensation
... These factors activate receptors on the nociceptor membrane. Nociceptors are divided in to 4 classes: mechanoreceptors, thermal receptors, chemoreceptors, and polymodal receptors (these respond to all 3 stimuli). Nociceptors are similar to other receptor types but generally respond to higher levels ...
... These factors activate receptors on the nociceptor membrane. Nociceptors are divided in to 4 classes: mechanoreceptors, thermal receptors, chemoreceptors, and polymodal receptors (these respond to all 3 stimuli). Nociceptors are similar to other receptor types but generally respond to higher levels ...
Electrophysiology - University of Nevada, Las Vegas
... The action potential appears to jump from node of Ranvier to node of Ranvier. Only the membrane at the node of Ranvier depolarizes, not the membrane under the myelin sheath. There are no ion channels under the myelin sheath. The jumping or saltatory conduction is much faster than depolarizing the en ...
... The action potential appears to jump from node of Ranvier to node of Ranvier. Only the membrane at the node of Ranvier depolarizes, not the membrane under the myelin sheath. There are no ion channels under the myelin sheath. The jumping or saltatory conduction is much faster than depolarizing the en ...
Patch clamp
The patch clamp technique is a laboratory technique in electrophysiology that allows the study of single or multiple ion channels in cells. The technique can be applied to a wide variety of cells, but is especially useful in the study of excitable cells such as neurons, cardiomyocytes, muscle fibers, and pancreatic beta cells. It can also be applied to the study of bacterial ion channels in specially prepared giant spheroplasts.The patch clamp technique is a refinement of the voltage clamp. Erwin Neher and Bert Sakmann developed the patch clamp in the late 1970s and early 1980s. This discovery made it possible to record the currents of single ion channel molecules for the first time, which improved understanding of the involvement of channels in fundamental cell processes such as action potentials and nerve activity. Neher and Sakmann received the Nobel Prize in Physiology or Medicine in 1991 for this work.