Homework 1: Describing Neural Communication
Kculver24
NerveImpulseAnalogySTUDENT_EXAMPLE.pptxBy Breanna Nelson PSB 3002
Nerve Impulse Analogy
1
It’s New Year’s Eve! Everyone has gathered at a New Year’s party. People are getting their drinks, mingling with friends and acquaintances, and finding the perfect spot to ring in the New Year. This can be compared to the resting potential. Everyone is calm, but ready for action.
In a neuron, the resting potential refers to a time when the neuron is more negatively charged on the inside, and more positively charged on the outside. The difference in charge is about -70 mV. The neuron is ready for action at this state.
At the party:
In a neuron:
Resting Potential
Resting Potential (in pictures)
At the party
In a neuron
The outside of the neuron is more positive. The inside is more negative. The difference in charge is around -70 mV.
Everyone’s ready for the big moment! It’s creeping closer to midnight, and on television, the ball in Time’s Square has just started to drop. The start of the countdown marks the threshold of excitation.
The threshold of excitation is reached when a stimulus occurs. Sodium channels snap open and sodium ions begins to rush into the neuron. This occurs at about -55 mV.
Threshold of Excitation
At the party:
In a neuron:
Threshold of Excitation (in pictures)
At the party
In a neuron
The New Year’s ball is starting to drop, marking the threshold of excitation.
The arrow is pointing to where the Threshold of Excitation is reached, at about -55 mV.
5
“10, 9, 8…” The excitement is rapidly, continually increasing with every passing second. “3, 2, 1… Happy New Year!” There’s cheering, confetti flies, and people blow their New Year horns. This finale sums up an action potential.
An action potential takes place once the threshold of excitation is reached. During the action potential, polarization of the neuron reverses. The inside of the neuron becomes more positively charged, and the outside becomes more negatively charged. Sodium, which is positively charged, is rushing inside the neuron. This is known as depolarization (the charge of the neuron is becoming more positive).
Action Potential
At the party:
In a neuron:
6
Action Potential (in pictures)
At the party
In a neuron
The inside of the neuron is rapidly becoming more positive, as sodium ions are rushing in.
All or None Law
No matter what, the countdown to midnight is always going to be the same. There is no way time can be rushed or sped along. This relates to the All or None Law.
At the party:
In a neuron:
The amplitude and velocity of an action potential is always going to be the same no matter how intense the initial stimulus was. It’s always the same process. This is the All or None Law.
After the initial cheering, it’s time for people to give their significant others a New Years kiss! Couples find each other and lock lips, just like neurotransmitters are released and find their receptors.
After a neuron fires, neurotransmitters are released. They can only bind to their specific receptors at their receptor sites. This is also known as lock and key.
Release of Neurotransmitters
At the party:
In a neuron:
The End
