Potensial Aksi (Action Potential)

Summary

This script delves into the intricacies of action potential in neurons, detailing its sequential and rapid occurrence in the axon. It explains how depolarization reaches a threshold, triggering an action potential that reverts to the resting state. The script contrasts action potentials with graded potentials, highlighting the latter's short-range communication and variable amplitude versus the long-range, uniform action potential. It also explores factors affecting conduction speed, such as myelination and axon diameter, and introduces the concept of refractory periods, crucial for preventing continuous firing. The discussion concludes with the impact of temperature on action potential speed and types of nerve fibers, emphasizing the importance of these concepts in understanding neural communication.

Takeaways

• 🧠 The action potential is a rapid and sequential process in the axon of a neuron that causes the membrane potential to become more positive and then return to the resting state.
• 🔔 The action potential has a threshold that must be reached by depolarization for it to occur, which is at -55 millivolts for a neuron.
• 🌀 The formation of an action potential depends on whether the stimulus can bring the membrane potential towards the threshold, with sub-threshold stimuli not triggering an action potential.
• 📶 Supra-threshold stimuli are strong enough to depolarize the membrane above the threshold, leading to the generation of an action potential.
• 🔊 The amplitude of the action potential remains the same regardless of the strength of the stimulus, but the frequency of action potentials increases with stronger stimuli.
• 🔄 The action potential consists of two phases: depolarization, where the membrane potential becomes less negative and can reach zero or positive values, and repolarization, where it returns to the resting state.
• ⚡️ Sometimes, repolarization is followed by a hyperpolarization phase, where the resting membrane potential becomes more negative temporarily.
• 🚫 During the absolute refractory period, no adequate stimulus can trigger another action potential, as the sodium channels are inactivated and potassium channels are open.
• 🔋 The speed of action potential conduction is influenced by factors such as myelination, axon diameter, and temperature.
• 🏃‍♂️ Conduction can be continuous or saltatory, with the latter being faster due to the presence of myelin sheaths that act as insulators, allowing for rapid 'jumping' between nodes of Ranvier.
• 🌐 The types of nerve fibers (A, B, and C) differ in diameter, myelination, conduction speed, and refractory period, with type A fibers being the fastest and type C the slowest.

Q & A

What is an action potential and what causes it?

An action potential is a rapid sequence of electrical changes in the membrane potential of a neuron, leading to a temporary reversal of the membrane potential. It is caused by the sequential opening and closing of ion channels, allowing the flow of ions to change the membrane potential from a resting state to a more positive state and then back to the resting state.

What is the threshold potential of an action potential?

The threshold potential is the level at which depolarization of the membrane potential must reach to initiate an action potential. It is the point at which the neuron becomes excited enough to trigger the action potential.

How does the strength of a stimulus affect the action potential?

The strength of a stimulus determines whether it can depolarize the membrane potential to the threshold level. If the stimulus is strong enough (suprathreshold), it will trigger an action potential. If the stimulus is not strong enough, it will not cause an action potential.

What are the two phases of an action potential?

The two phases of an action potential are depolarization, where the membrane potential becomes less negative or even positive, and repolarization, where the membrane potential returns to its resting state.

What is hyperpolarization and when does it occur?

Hyperpolarization is a temporary state where the membrane potential becomes more negative than the resting potential. It can occur after the repolarization phase of an action potential, making the neuron less likely to fire another action potential immediately.

What is the difference between a local potential and an action potential?

A local potential, such as a graded potential, occurs in the soma and dendrites and can be short-range communication. An action potential, on the other hand, occurs in the axon and is used for long-range communication. The amplitude of a local potential can vary, while the amplitude of an action potential is consistent and does not decrease with distance.

How do the sodium and potassium ion channels contribute to the action potential?

Sodium ion channels open during depolarization, allowing sodium ions to flow into the cell, making the membrane potential more positive. Potassium ion channels open during repolarization, allowing potassium ions to flow out of the cell, making the membrane potential more negative and returning it to the resting state.

What is the refractory period and why is it important?

The refractory period is a time after an action potential when the neuron is less responsive or unresponsive to stimuli. It is important because it ensures that action potentials only occur in one direction along the axon and prevents the neuron from firing multiple action potentials too quickly.

What are the two types of refractory periods?

There are two types of refractory periods: the absolute refractory period, during which no stimulus, regardless of strength, can trigger another action potential, and the relative refractory period, during which only a stronger-than-normal stimulus can trigger another action potential.

How does the presence of myelin sheaths affect the conduction of action potentials?

Myelin sheaths act as insulators, speeding up the conduction of action potentials by preventing the leakage of electrical current from the axon. This is known as saltatory conduction, where the action potential 'jumps' from one node of Ranvier to the next, making it more efficient and faster.

What factors influence the speed of action potential conduction?

Factors that influence the speed of action potential conduction include the diameter of the axon, the presence of myelin sheaths, and the temperature. Larger diameter axons and myelinated axons conduct action potentials faster, and higher temperatures can also increase the speed of conduction.

Outlines

00:00

🧠 Action Potential Process in Neurons

This paragraph explains the concept of action potential in neurons. It describes the sequential process of depolarization and repolarization that occurs rapidly along the axon of a neuron, leading to a change in membrane potential from negative to positive and back to its resting state. The action potential threshold is discussed, indicating that it only occurs when the membrane potential reaches a certain level, which for neurons is mentioned as -55 millivolts. The paragraph also touches on the amplitude of the action potential and how it remains constant regardless of the stimulus strength, while the frequency of action potentials increases with stronger stimuli. The phases of the action potential, including depolarization, repolarization, and sometimes hyperpolarization, are also detailed.

05:02

🔬 Mechanisms of Depolarization and Repolarization

The second paragraph delves into the mechanisms behind depolarization and repolarization. It discusses the role of sodium and potassium channels, explaining how the opening and closing of these channels lead to changes in the membrane potential. The paragraph describes the process of inactivation gates and activation gates in sodium channels, and the single gate in potassium channels. It also explains how the resting membrane potential is maintained and how stimuli can initiate an action potential. The difference between local and distant communication via potential gradients is highlighted, with the former being short-range and the latter suitable for long-range communication.

10:04

🚀 Factors Influencing the Speed of Action Potential Conduction

This paragraph explores the factors that affect the speed at which an action potential is conducted along a neuron. It explains the difference between continuous and saltatory conduction, with the latter being a faster method due to the presence of myelin sheaths that act as insulators, allowing electrical signals to 'jump' between nodes of Ranvier. The paragraph also discusses how the diameter and myelination of an axon, as well as temperature, can influence the speed of action potential propagation. Different types of neurons, such as A, B, and C, are mentioned, each with varying diameters, myelination, and conduction speeds.

15:05

⏱️ Refractory Periods of Neurons

The fourth paragraph focuses on the refractory periods of neurons, which are the times during which a neuron cannot respond to stimuli following an action potential. It differentiates between the absolute refractory period, where no stimulus can trigger another action potential, and the relative refractory period, where only suprathreshold stimuli can elicit a response. The paragraph also compares the refractory periods and impulse conduction capabilities of different types of neurons, such as type A and type C, highlighting their differences in recovery time and impulse frequency.

20:21

🎵 Animated Illustration of Action Potential

The final paragraph does not contain any scientific content but seems to be a playful or musical interlude, possibly indicating a transition or conclusion in the video. It includes repeated greetings and laughter, suggesting a light-hearted or engaging tone. There is no summary required for this paragraph as it does not provide informational content.

Keywords

💡Action Potential

Action potential refers to the rapid, sequential, and rapid change in the membrane potential of a neuron, causing it to become more positive and then return to its resting state. It is central to the video's theme as it explains the fundamental process of how neurons transmit signals. In the script, it is described as having a threshold that must be reached for depolarization to occur, leading to the action potential.

💡Threshold

The threshold is the level at which the membrane potential must reach to initiate an action potential. It is a crucial concept in the video as it determines whether a stimulus is strong enough to trigger an action potential. The script mentions that the neuron's threshold is at -55 millivolts, indicating the minimum depolarization required.

💡Depolarization

Depolarization is the process where the membrane potential becomes less negative or even positive, which is a phase of the action potential. It is essential to the video's narrative as it illustrates how a stimulus can influence the neuron's membrane potential towards the threshold. The script describes it as a weak or strong process depending on the stimulus, leading to or preventing an action potential.

💡Repolarization

Repolarization is the phase following depolarization where the membrane potential returns to its resting state. It is a key part of the action potential cycle depicted in the video. The script explains that this occurs due to the opening of potassium channels, allowing potassium ions to exit the cell, thus restoring the negative charge inside the cell.

💡Hyperpolarization

Hyperpolarization is a temporary state where the membrane potential becomes more negative than the resting potential. It is mentioned in the script as a phase that can follow repolarization, indicating a state where the neuron is less likely to generate another action potential immediately after one has occurred.

💡Voltage-Gated Channels

Voltage-gated channels are proteins in the neuron's membrane that open and close in response to changes in membrane potential. They are vital to the video's explanation of action potentials as they allow the flow of ions (sodium and potassium) that cause depolarization and repolarization. The script describes their role in the process, such as sodium channels opening during depolarization and potassium channels opening during repolarization.

💡Myelin Sheath

The myelin sheath is a protective layer that insulates some neurons and increases the speed of signal transmission. It is related to the video's theme as it discusses how the myelin sheath affects the conduction of action potentials. The script explains that action potentials 'jump' between nodes of Ranvier due to the myelin sheath, a process known as saltatory conduction.

💡Saltatory Conduction

Saltatory conduction is the process by which action potentials 'jump' from one node of Ranvier to the next along a myelinated axon. It is a key concept in the video as it describes a faster method of signal transmission along neurons. The script illustrates this with the example of myelinated axons, where the myelin sheath acts as an insulator, speeding up the action potential propagation.

💡Refractory Period

The refractory period is a time following an action potential when a neuron is unable to generate another action potential, regardless of the stimulus. It is important to the video's message as it explains the limitations on how frequently a neuron can fire. The script distinguishes between the absolute and relative refractory periods, detailing their durations and implications for neuronal signaling.

💡Neurotransmitter

Neurotransmitters are chemical messengers that transmit signals across a synapse from one neuron to another. While not explicitly detailed in the script, the concept is implied in the discussion of synaptic communication and the triggering of action potentials. Neurotransmitters play a role in the initiation of action potentials at the postsynaptic neuron.

💡Conduction Velocity

Conduction velocity is the speed at which an action potential travels along an axon. It is relevant to the video's theme as it discusses factors that affect how quickly signals are transmitted. The script mentions that the diameter of the axon and the presence of a myelin sheath are factors that influence the conduction velocity, with larger diameters and myelinated axons having faster velocities.

Highlights

The action potential is a rapid and sequential process occurring at the axon of a neuron, causing the membrane potential to become more positive before returning to the resting state.

The action potential has a threshold that must be reached for depolarization to occur, which is at -55 millivolts for neurons.

The formation of the action potential depends on whether the stimulus can bring the membrane potential towards the threshold, with superthreshold stimuli being strong enough to trigger it.

Subthreshold stimuli are not strong enough to cause an action potential, while suprathreshold stimuli can depolarize the neuron membrane and generate an action potential.

The amplitude of the action potential is the same regardless of the stimulus strength, but the frequency of action potentials increases with stronger stimuli.

There are two phases of the action potential: depolarization, where the membrane potential becomes less negative or even positive, and repolarization, where it returns to the resting state.

Hyperpolarization may follow repolarization, temporarily making the resting membrane potential more negative than usual.

The resting membrane potential is maintained by the sodium-potassium pump, keeping the inside of the neuron negative and the outside positive.

Sodium channels have two gates: the activation gate and the inactivation gate, which open and close in a coordinated manner during depolarization and repolarization.

The difference between local potentials and action potentials lies in their location, with local potentials occurring in the soma and dendrites, while action potentials occur in the axon.

Local potentials are for short-range communication and diminish in strength over distance, unlike action potentials which are uniform in amplitude for long-range communication.

The opening of voltage-gated sodium channels during depolarization allows sodium ions to enter the cell, changing the membrane potential to be more positive.

Repolarization occurs when the inactivation gate of the sodium channels closes and the potassium channels open, allowing potassium ions to exit the cell.

The refractory period of a neuron is when it does not respond to stimuli, which has two phases: the absolute refractory period and the relative refractory period.

The speed of action potential conduction is influenced by factors such as myelination, axon diameter, and temperature.

Conduction can be continuous or saltatory, with saltatory conduction being faster due to the presence of myelin sheaths and nodes of Ranvier.

Types of nerve fibers (A, B, and C) differ in diameter, myelination, conduction speed, and refractory period, affecting their function in transmitting impulses.

An animation is provided to visually demonstrate the process of action potential generation and propagation along the neuron.

Transcripts

tips potensial aksi atau impuls adalah

proses yang terjadi secara sekuens dan

secara cepat di akson dari suatu neuron

proses ini menyebabkan potensial membran

itu akan berubah menjadi lebih positif

lalu kemudian kembali lagi ke posisi

awal pada saat istirahat potensial aksi

ini memiliki threshold potensial aksi

hanya akan terjadi ketika depolarisasi

dari potensial berjenjang itu mencapai

level tertentu yang disebut threshold

Nah untuk neuron threshold nya atau

ambang batasnya adalah minus 55 milik

VOC pembentukan dari potensial aksi

tergantung Apakah stimulus tersebut

dapat membawa potensial membran menuju

ke arah threshold stimulus itu ada yang

jenisnya adalah supershow jika

potensial yang terbentuk itu tidak dapat

memicu sampai ke minus 55 ini karena

Depo Laras depolarisasi yang terjadi itu

lemah kemudian ada stimulus threshold

ketika dapat memicu potensial aksi dan

dapat mendepolarisasi membran saraf

sehingga akan muncul potensial aksi Lalu

ada beberapa potensial aksi yang dia

adalah stimulus Supra threshold cukup

kuat untuk mendepolarisasi membran di

atas dari threshold lihat di sini Jika

stimulus itu datang tidak cukup kuat

maka tidak akan muncul potensial aksi

jika sudah mencapai ambang maka muncul

potensial aksi jika melebihi ambang maka

potensial aksi yang terbentuk

amplitudonya sama seperti halnya

stimulus yang merangsang sampai ke

threshold jadi walaupun steam

yang datang lebih besar namun amplitudo

dari yang terbentuk adalah sama yang

berbeda adalah frekuensi dari potensial

aksi nya semakin besar stimulus yang

datang maka akan semakin banyak

potensial aksi yang terbentuk fase dari

potensial aksi ada dua yaitu fase

depolarisasi ketika potensial membran

itu menjadi kurang negatif bahkan

mencapai Zero dan menjadi positif

kemudian fase repolarisasi ketika

potensial membran itu kembali ke posisi

awal saat istirahat yaitu minus 7

milivolt terkadang Fase repolarisasi ini

diikuti oleh fase hiperpolarisasi ketika

potensial membran istirahat secara

sementara atau temporer itu menjadi

lebih negatif daripada saat istirahatnya

menjadi melebihi

s70 milik volt nah perhatikan di sini ya

ketika ada stimulus yang dapat memicu

sampai ambang batas yang menambah 15

milivolt Maka akan muncul potensial aksi

fase pertama adalah depolarisasi menjadi

makin positif yang bahkan bisa mencapai

positif tiga puluh mili volt nah Setelah

itu dilanjutkan dengan repolarisasi

kembali ke polarisasi awal yakni minus

70 milivolt namun ada hiperpolarisasi

yang melebihi minus 79 terlalu kemudian

kembali ke potensial membran istirahat

proses ini ya ini ini disebut dengan

potensial membran istirahat ketika kenal

voltase natrium dalam posisi istirahat

dan karena voltase kalium itu tertutup

ketika ada stimulus yang berwarna biru

ya yang memicu depolarisasi ketika

potensial berjenjang yang sudah

1255 milik Fox akan dilanjutkan dengan

potensial aksi di bagian aksonnya selalu

Hai depolarisasi terjadi karena

terbukanya kanal gerbang voltase natrium

repolarisasi ini terjadi karena

terbukanya karena voltase kalium

hiperpolarisasi terjadi karena masih

terbukanya karena voltase kalium

perhatikan di sini ya pada saat

istirahat semua karena voltase natrium

maupun kalium itu tertutup di dalam sini

adalah minus 70 milivolt didalamnya

adalah negatif dan diluar itu positif

lihat bahwa kenal voltase dari Natrium

itu punya dua pintu ya diibaratkan

seperti punya dua pintu yang seini

adalah gerbang inactivation atau gerbang

inaktif dan ini adalah gerbang aktif

sedangkan yang kalium itu hanya punya

satu pintu ketika terdapat

stimulus-stimulus potensial berjenjang

sudah terjadi mencapai

Hai maka akan ada fase depolarisasi

kanal natrium ya gerbang yang aktivasi

akan terbuka karena aktivasi akan

terbuka sehingga natrium dapat masuk ke

dalam sel akhirnya di dalam sel makin

banyak ion positif sehingga akan

mengubah potensial membran menjadi lebih

positif dalam hal ini terdepolarisasi

final lalu kemudian sampai positif 30

lalu kemudian ketika sudah sampai ke

positif 30 milivolt maka muncullah fase

repolarisasi ketika daun pintu yang

inaktivasi itu akan menutup signal dan

karena kalium akan terbuka sehingga

menyebabkan kalium yang banyak di dalam

sel keluar tadinya yang di dalam sini

itu positif Karena ada ion positif yang

keluar maka akan

negatif selanjutnya keluarnya ion kalium

ini call natrium itu yang tadinya pintu

atau gerbang inaktivasi itu menutup

tadinya menutup ini membuka sedangkan

yang posisi dari gerbang aktivasi itu

menutup jadi ini membuka menutupnya

bergantian setelah itu kembali ke posisi

awal yaitu pada saat istirahat Nella

karep kenal terbang yang inaktivasi dan

ini ada yang aktivasi ya ketika

istirahat maka ini menutup semua ini

karena gerbang voltase ya lalu kemudian

ketika ada stimulus maka kenal natrium

akan terbuka akan terjadi depolarisasi

lalu selanjutnya repolarisasi terjadi

karena kanal natrium tertutup dan kanal

kalium terbuka nah ini

nutup ya kenal ya gerbang inaktivasi itu

menutupnya pada saat repolarisasi

kemudian pada saat hiperpolarisasi yang

bagian enaktif ini ada akan lepas dan

bagian yang aktif akan menutup merek

tanahnya nah lalu kembali ke posisi

istirahat jadi perbedaan dari potensial

berjenjang dan potensial aksi adalah

lokasinya dari segi lokasi kalau

potensial berjenjang terjadi pada Soma

dan dendrit sedangkan potensial aksi

terjadi pada akson kalau potensial

berjenjang itu jaraknya hanya singkat

Tadi saya sudah sebutkan bahwa potensial

berenang hanya untuk komunikasi yang

jarak singkat sedangkan potensial aksi

untuk komunikasi jarak jauh kemudian

ukuran dari amplitudonya itu bervariasi

makanya disebut berjenjang dan dia akan

menghilang semakin jauh makankah

tapi menghilang Sedangkan untuk

potensial aksi itu sama dalam hal ini

adalah old ornamen Jadi kalau tidak

mencapai threshold maka tidak akan

muncul potensial aksi seperti halnya

dorong Domino yang pertama itu dapat

memicu rentetan jatuhnya Domino

selanjutnya lalu kemudian stimulus untuk

membuka kanal ion kalau untuk potensial

bersenjang adalah kimiawi atau

neurotransmitter itu kalau pada

potensial postsinaptic dan stimulus

sensoris itu contohnya pada potensial

reseptor nah Sedangkan untuk potensial

aksi yang terbuka adalah karena voltase

Nah untuk feedback positifnya ini tidak

ada feedback positif tapi pada potensial

aksi ada feedback positif maksudnya

ketika sudah ada satu karena Land

terbuka ya maka akan menyebabkan

terpicunya terbukanya kanal kanal

lainnya

model pada fase repolarisasi tidak

tergantung pada voltase Ia hanya akan

terpolarisasi potensial berjenjang itu

kalau stimulusnya hilang sedangkan pada

potensial aksi itu diatur oleh voltase

yaitu ketika kanal natrium itu

inaktivasi dan kanal kalium terbuka maka

barulah terjadi fase repolarisasi Nah

untuk sumasi pada potensial berjenjang

itu dapat terjadi itu masih sedangkan

pada potensial aksi tidak terjadi

sumatif pada potensial berjenjang itu

ada potensial postsinaptic yaitu nanti

kita bahas fsp maupun ipsp sedangkan

potensial aksi itu adalah sinyal jarak

jauh efek dari ketika ada stimulus akan

membuka karena berlubang kimiawi dalam

hal ini misalnya ligan ketika terbuka

makan menyebabkan natrium-kalium dapat

pindah ya Sedangkan untuk potensial aksi

yang terbuka adalah kenal voltase

potensial membran puncak dari potensial

membran nya terdepolarisasi yaitu

berpindah ya kalau depolarisasi itu

menuju kearah nol sedangkan kalau

hiperpolarisasi menuju kearah minus 90

nah sedangkan kalau potensial aksi dapat

mencapai positif 30 sampai positif 50

milih volt nah dan namanya periode

refraktori yaitu periode ketika syaraf

kita tidak akan berespon terhadap

stimulus yang adekuat ada dua yang

pertama adalah periode refraktori

Absolute itu dimulai dari fairing level

sampai sepertiga dari repolarisasi

kemudian roda refractory relatif dari

sepertiga repolarisasi sampai awal dari

depolarisasi selanjutnya nah pada

periode refraktori yang absolut ini maka

stimulus

yang baik itu adekuat maupun yang di

atas dari travel atau Supra threshold

tidak akan dapat memicu munculnya

potensial aksi kembali periode

refraktori relatif maka inilah neuron

itu dapat distimulasi jika stimulus yang

datang itu melebihi normal Mengapa

Hollywood itu terjadi karena kanal

natrium karena natrium posisi dari

gerbang inaktif maupun aktifnya itu

harus kembali ke posisi istirahat nanti

dia tidak bisa membuka jika tidak

kembali ke posisi istirahat penjalaran

dari potensial aksi secara konduksi

continuous atau berkelanjutan dan

konduksi lompatan atau saltatori

perhatikan disini misalnya pada dendrit

ke membran plasma yang tidak punya kanal

maupun selubung myelin nah pada dendrit

maka voltase itu akan menghilang Ya

karena adanya kebocoran aliran

Hai yang melewati membran potensial

berenang itu tidak bisa berjalan dalam

jarak jauhnya karena dan Rip tidak

sesuai untuk perjalanan aliran listrik

jarak jauh selanjutnya ini ketika ada

akson yang tidak bermyelin itu banyak

karena gerbang voltase karena gerbang

voltase akan membuka karena adanya

perubahan kelistrikan di membran saraf

karena gerbang voltase ini membuka

Seiring dengan berjalannya aliran

listrik Nah konduksi Ini lambat karena

butuh waktu untuk si ion dan si gerbang

ini untuk terbuka sehingga konduksi yang

berkelanjutan tanpa adanya selubung

myelin itu berjalan dengan lambat

perhatikan pada akson yang bermielin ini

terjadi konduksi secara cepat seperti

halnya seakan-akan terjadi lompatan

antara satu nodus ranvier ke nodus

ranvier lainnya

hal ini disebut konduksi saltatori nah

selubung myelin akan menjaga aliran dari

Akson sehingga aliran tersebut tidak

bocor keluar dari membran jadi sebagai

insulator perhatikan disini bahwa di

bagian nodus ranvier lah yang terdapat

kanal ion jadi aliran listrik itu dapat

berjalan lebih cepat karena tidak perlu

ada banyak pembukaan dari kanal ion

disepanjang dari membran neuron hanya

pada tempat-tempat tertentu saja ya yang

terbuka anak lainnya dan aliran listrik

tetap terjaga karena ada selubung mielin

dan ini juga lebih hemat energi karena

tidak perlu banyak ATP untuk membuka

banyak Kenal in jadi faktor-faktor yang

mempengaruhi kecepatan konduksi dari

potensial aksi yang pertama adalah

banyaknya jumlah mili nisasi semakin

tebal miliknya semakin banyak selubung

selubungnya maka akan semakin cepat

grupnya yang kedua adalah diameter dari

Akson semakin lebar aksonnya maka akan

semakin cepat propagasi impulsnya karena

makin luas permukaan dari Akson tersebut

ketika dua suhu potensial aksi itu akan

berjalan lambat pada suhu yang rendah

nah ini contohnya tipe-tipe Serabut

saraf pada rentcars kita ada yang a b

dan c dana itu ada Alfa abeta agama dan

adelta diameternya ini besarnya 12-20

mikrometer dan kecepatan konduksinya

70-120 militer second dengan fungsinya

masing-masing misalnya Alfa itu untuk

propriosepsi dan untuk neuron pemantik

yang B dan C semakin kesini P ini kecil

ya kecil dan lihat ya bahwa yang ada dan

b itu serabutnya bermyelin danste itu

tidak bermielin

periode refraktori nya pada yang tipe

serabut a-line besar Maka luas

permukaannya juga besar dan periode

refraktori nya itu ternyata lebih

singkat hanya 0,4 by sekon sehingga

memungkinkan serabut tipe a ini dapat

membawa impuls mencapai 1.000 impuls per

detik sedangkan pada type C periode

refraktori nya lebih lama bisa sampai 4

milih second dan hanya mampu membawa

maksimum impuls atau potensi Axis

sekitar 250 impuls per detik untuk lebih

jelasnya mengenai potensial aksi maka

dapat diamati animasi berikut

hai hai

ia tersenyum my

hai hai

hai hai

hai hai

hai hai

hai hai

hai hai

hai hai

hai hai

[Musik]

morning

hai hai

Hai ketemu lagi

[Musik]

hai hai

hai hai

hai hai

hai hai

hai hai

hai hai