Notes in NAS III (Action potential)

To Subscribe, use this Key

Status	Last Update	Fields
Published	11/11/2024	An {{c1::action potential}} is triggered by an {{c2::initial influx}} of  {{c2::Na⁺ (sodium) ions}} into the cell.
Published	11/11/2024	The {{c2::threshold potentia}}l that must be reached to trigger an action potential is approximately -{{c1::55 mV}}.
Published	11/11/2024	The stimulus for action potential initiation can be {{c1::mechanical}}, {{c1::chemical}}, or {{c1::electrical}}.
Published	11/11/2024	In {{c1::mechanoreceptors}}, action potentials can be initiated by {{c2::mechanical pressure}}, which opens {{c2::ion channels}}.
Published	11/11/2024	The {{c1::all-or-nothing principle}} means that action potentials, once triggered, have the {{c2::same intensity}}, regardless of the {{c3::stimulus s…
Published	11/11/2024	The initial {{c1::small depolarization}} of the membrane potential is caused by the influx of {{c1::Na⁺ ions}}.
Published	11/11/2024	If the {{c1::threshold potential}} is reached, a {{c2::positive feedback mechanism}} leads to the {{c2::generation of an action potential}}.
Published	11/11/2024	Once the membrane potential reaches {{c1::the threshold potential}}, {{c3::voltage-gated Na⁺ channels}} open fully, allowing {{c2::a large influx of i…
Published	11/11/2024	The {{c2::depolarization}} phase of the action potential drives the {{c3::membrane potential}} to approximately {{c1::+30 mV}}.
Published	11/11/2024	After {{c1::depolarization}}, {{c2::K⁺ (potassium) channels open}} to allow ions to exit the cell, causing {{c3::repolarization}}.
Published	11/11/2024	{{c2::Hyperpolarization}} occurs when the {{c4::current membrane potential}} becomes more {{c1::negative}} than the {{c3::resting potential}}.
Published	11/11/2024	The purpose of {{c1::hyperpolarisation}} is to {{c2::stop the nerve cell from absorbing another input}} by {{c3::increasing the barrier of any incomin…
Published	11/11/2024	16e931b6f1d74b72a8624d47211d73a2-ao-1
Published	11/11/2024	16e931b6f1d74b72a8624d47211d73a2-ao-2
Published	11/11/2024	16e931b6f1d74b72a8624d47211d73a2-ao-3
Published	11/11/2024	16e931b6f1d74b72a8624d47211d73a2-ao-4
Published	11/11/2024	16e931b6f1d74b72a8624d47211d73a2-ao-5
Published	11/11/2024	16e931b6f1d74b72a8624d47211d73a2-ao-6
Published	11/11/2024	The {{c1::absolute refractory period}} is the {{c2::time following an action potential}} during {{c2::which a new action potential cannot be generated…
Published	11/11/2024	The {{c1::relative refractory period }} is the phase during which {{c2::a new action potential can be generated}}, but {{c2::it requires a much s…
Published	11/11/2024	The absolute refractory period is caused by the {{c1::opening}} or {{c1::inactivation}} of voltage-gated Na⁺ channels.
Published	11/11/2024	In {{c1::unmyelinated}} neurons, action potentials propagate by {{c3::local circuits}}, where Na⁺ ions cause {{c2::neighboring Na⁺ channels}} to {{c2:…
Published	11/11/2024	Continuous conduction of action potentials in {{c3::unmyelinated neurons}} is {{c1::slower}} and less {{c1::energy-efficient}} than in {{c3::myelinate…
Published	11/11/2024	In {{c2::myelinated neurons}}, action potentials propagate via {{c1::saltatory conduction}}, where {{c3::signals jump}} between {{c3::nodes of Ranvier…
Published	11/11/2024	{{c4::Saltatory conduction}} is {{c1::faster}} and more {{c2::energy-efficient}} than {{c3::continuous conduction}}.
Published	11/11/2024	{{c3::Voltage-gated Ca²⁺ channels}} are known as {{c1::slow channels}} because they {{c2::open and close}} more {{c4::slowly}} than {{c1::Na⁺ cha…
Published	11/11/2024	The influx of {{c2::Ca²⁺ ions}} during {{c1::depolarization}} contributes to {{c2::longer-lasting}} action potentials.
Published	11/11/2024	Ca²⁺ ions reduce cell excitability by raising the threshold for {{c1::voltage-gated Na⁺ (sodium)}} channels.
Published	11/11/2024	By raising the {{c1::threshold for Na⁺ channels}}, Ca²⁺ ions help prevent {{c2::muscle tetany}} , which is characterized by {{c1::uncontrolled mu…
Published	11/11/2024	Ca²⁺ channels open during the {{c1::depolarization phase}} of an action potential, allowing {{c2::Ca²⁺ ions into the cell}}.
Status	Last Update	Fields