...pumps, cotransporters and channels, which transport salt...
...lumen via chloride channels The gastric mucosa...
...specific passive ion channels. Ions also flow...
...flow through these channels down the concentration...
...passive transport. K+ channels are the most...
...specific voltage-gated ion channels that open when...
...membrane. Voltage-gated ion channels are of two...
...two kinds, potassium channels and sodium channels....
...channels and sodium channels. When the change...
...changes shape, the channels open and Na+...
...the cell. Na+ channels stay open for...
...the voltage-activated sodium-ion channels is -55mV. The...
...time, the sodium-ion channels close. The closing...
...on voltage. K+ channels also open but...
...later when the channels close and the...
...sodium and potassium channels are closed, and...
...Depolarization phase. Sodium channels open and Na+...
...more positive. Potassium channels remain closed. 3....
...Repolarization phase. Sodium channels close and potassium...
...close and potassium channels open. Leakage of...
...hyperpolarization, the sodium channels are closed. The...
...concentration of voltage-gated channels and supports action...
...chemically activated ion channels in the membrane...
...activates voltage-sensitive Ca+ channels. Ca+ from the...
...chemically activated ion channels. They are called...
...called ligand-gated ion channels. The neurotransmitter, the...
...Opening of the channels may cause a...
...receptors control gated channels that allow the...
...by opening ion channels that make the...
...where voltage-gated sodium channels open and generate...
...and specific ion channels open or close....
...have the Na+ channels open and are...
...to GMP. Sodium channels must be bound...
...increases, the Na+ channels begin to close...

...anion. Ungated ion channels allow ions to...
...plasma membrane. These channels are always open....
...potentials. Gated ion channels open or close...
...ions. Chemically-gated ion channels open or close...
...stimulus. Voltage-gated ion channels open or close...
...Hyperpolarization. Gated K+ channels open K+ diffuses...
...Depolarization. Gated Na+ channels open Na+ diffuses...
...closed voltage-gated K+ channels open slowly in...
...depolarization. Voltage-gated Na+ channels have two gates....
...synapses. Postsynaptic chemically-gated channels exist for ions...
...receptors opens gated channels that allow Na+...
...receptors open gated channels that allow K+...

...PUMPS AND ION CHANNELS Ion pumps and...
...pumps and ion channels maintain the resting...
...fluid. GATED IONS CHANNELS The resting potential...
...Na+ through ion channels that are always...
...always open; these channels are said to...
...have gated ion channels, which open or...
...stimuli. Stretch-gated ion channels: found in cells...
...deformed. Ligand-gated ion channels are found at...
...channel. Voltage-gated ion channels are found in...
...due to more channels opening, and the...
...specific voltage-activated ion channels that open when...
...changes shape, the channels open and Na+...
...the voltage-activated sodium-ion channels is -55mV. B)...
...Na+ permeability; K+-gated channels remain closed, Followed...
...milliseconds, the sodium-ion channels close. The closing...
...on voltage. K+ channels also open but...
...when the Na+ channels close and the...
...negative state. Potassium-gated channels respond slowly and...
...because the ion-gated channels are closed and...
...Na+ and K+ channels are concentrated at...
...synapses contain protein channels (gap junctions) that...
...chemically activated ion channels in the membrane...
...wave opens calcium channels and allows Ca2+...
...and open ion channels that initiate a...
...closes the ion channels and terminates the...
...and open ion channels that initiate a...
...neurotransmitters open sodium channels and bring the...
...open potassium ion channels making it easier...
...linked to ion channels in postsynaptic neurons....
...affect specific ion channels. In long term...
...cell. Glutamate opens gated-channels that allow Ca2+...

...pumps and ion channels maintain the resting...
...potential involves ion channels, pores formed by...
...the membrane. Ion channels allow ions to...
...ions diffuse through channels, they carry with...
...membrane. The ion channels that establish the...
...many open potassium channels but very few...
...few open sodium channels. The diffusion of...
...through open potassium channels is critical for...
...mammalian neuron, ion channels allow K+ to...
...Because the potassium channels allow only K+...
...many open ion channels, all of which...
...few open sodium channels in a resting...
...the only open channels were selective for...
...many open potassium channels but only a...
...of open sodium channels. Neither K+ nor...
...many open K+ channels but only a...
...few open Na+ channels. When neurons are...
...number of open channels for these ions...
...have gated ion channels, which open or...
...stimuli. Gated ion channels are responsible for...
...has gated ion channels, the membrane’s permeability...
...close the ion channels. The resulting changes...
...the gated K+ channels that are closed...
...Opening more K+ channels increases the membrane’s...
...Although opening K+ channels causes hyperpolarization, opening...
...types of ion channels, such as gated...
...as gated sodium channels, makes the inside...
...depolarization. Gated Na+ channels open, Na+ diffuses...
...the gated ion channels in neurons are...
...opens voltage-gated sodium channels, the resulting flow...
...Because the sodium channels are voltage gated,...
...causes more sodium channels to open, leading...
...the voltage-gated sodium channels. Changes in membrane...
...opens voltage-gated sodium channels and the opening...
...opening of sodium channels causes further depolarization....
...Na+ and K+ channels. Na+ channels open...
...K+ channels. Na+ channels open first, initiating...
...proceeds, the Na+ channels undergo inactivation as...
...the opening. Na+ channels remain inactivated until...
...potential and the channels close. K+ channels...
...channels close. K+ channels open more slowly...
...slowly than Na+ channels, but remain open...
...action potential. Voltage-gated channels shape the action...
...most voltage-gated Na+ channels are closed. Some...
...closed. Some K+ channels are open, but...
...most voltage-gated K+ channels are closed. When...
...some gated Na+ channels open, allowing more...
...more gated Na+ channels, allowing even more...
...ENa. Voltage-gated Na+ channels inactivate soon after...
...Most voltage-gated K+ channels open, causing a...
...potential. The K+ channels eventually close, and...
...potential. The Na+ channels remain inactivated during...
...inactivation of Na+ channels, not by a...
...zone, the Na+ channels remain inactivated. Consequently,...
...axon, voltage-gated sodium channels are restricted to...
...opening voltage-gated calcium channels in the membrane....
...synapses, ligand-gated ion channels capable of binding...
...neurotransmitter binds to channels that are selectively...
...receptors opens gated channels that allow K+...
...of open potassium channels. cAMP is one...
...or close many channels. The same neurotransmitter...
...receptors on ligand-gated channels in the muscle...
...and open K+ channels in the muscle...

...1 Ligand-gated ion channels c Action Potential...
...Other ligand-gated ion channels Receptors for some...
...Other ligand-gated ion channels have similar structure...
...structure However, chloride channels such as the...
...effect ligand-gated ion channels (Antagonists) Drugs and...
...effect ligand-gated ion channels (Agonists) 5 GPCR...
...enzymes and ion channels) GPCR Signaling GPCRs...

...opening of chloride channels. A massive diarrhoea...
...LEVEL INCREASES, CHLORIDE CHANNELS ARE OPEN, CAUSING...
...OPENING EXTRACELLULAR CACLIUM CHANNELS. Compare and contrast...
...OPENING OF CALCIUM CHANNELS IN THE MEMBRANE....