Nerve impulse

dendrites

axon terminals

axon

myelin



Synapse (space between two neurons)

A nerve signal (action potential) travels through a neuron beginning at the dendrites, down the axon, and to the axon terminals. The membrane of the axon is polarized, meaning the external face is is positive and the internal is negative. Once the signal arrives, the membrane depolarizes, which is the opposite of polarization.

Neurotransmitter has a complimentary shape to thereceptors.The neurotransmitter molecules are then released from the axon terminals and into the synaptic cleft

At rest the outside of the membrane is +charged compared with the inside.The membrane is polarised.At rest – sodium ion channels in the membrane are closed. The resting potential and is -70mV

The molecules diffuse across the synapse (small gap between neurons) and then bind to the receptors of the next neuron's membrane.An action potential starts when a stimulus causes the membrane of one part of the axon to change in permeability. The inside of the neurone changes from -70mV to +40mV.

The Na ion channels of the receiving neuron open up, where sodium ions enter and cause depolarisationthat spreads down the neuron as a wave of depolarisation. The inside becomes positive compared to the outside.

.



Ion channel

Na+

transmitter

The ion channel closes, then releases the neurotransmitter which is now broken down

Finally, repolarization occurs, where the internal face of the membrane becomes negative again and the external becomes positive. During this step, potassium ion channels open to allow potassium to diffuse out.

- - - - - - - - - - - - -

+ + + + + + + + + + +

+ + + + + + + + + + +

K+

neurotransmitter molecules

The neurotransmitters must move very quickly! Or else, they will be removed from the synapse via diffusion.

dendrites

axon terminals

axon

myelin



Synapse (space between two neurons)

A nerve signal (action potential) travels through a neuron beginning at the dendrites, down the axon, and to the axon terminals. The membrane of the axon is polarized, meaning the external face is is positive and the internal is negative. Once the signal arrives, the membrane depolarizes, which is the opposite of polarization.

Neurotransmitter has a complimentary shape to thereceptors.The neurotransmitter molecules are then released from the axon terminals and into the synaptic cleft

At rest the outside of the membrane is +charged compared with the inside.The membrane is polarised.At rest – sodium ion channels in the membrane are closed. The resting potential and is -70mV

The molecules diffuse across the synapse (small gap between neurons) and then bind to the receptors of the next neuron's membrane.An action potential starts when a stimulus causes the membrane of one part of the axon to change in permeability. The inside of the neurone changes from -70mV to +40mV.

The Na ion channels of the receiving neuron open up, where sodium ions enter and cause depolarisationthat spreads down the neuron as a wave of depolarisation. The inside becomes positive compared to the outside.

.



Ion channel

Na+

transmitter

The ion channel closes, then releases the neurotransmitter which is now broken down

Finally, repolarization occurs, where the internal face of the membrane becomes negative again and the external becomes positive. During this step, potassium ion channels open to allow potassium to diffuse out.

- - - - - - - - - - - - -

+ + + + + + + + + + +

+ + + + + + + + + + +

K+

neurotransmitter molecules

The neurotransmitters must move very quickly! Or else, they will be removed from the synapse via diffusion.

dendrites

axon terminals

axon

myelin



Synapse (space between two neurons)

A nerve signal (action potential) travels through a neuron beginning at the dendrites, down the axon, and to the axon terminals. The membrane of the axon is polarized, meaning the external face is is positive and the internal is negative. Once the signal arrives, the membrane depolarizes, which is the opposite of polarization.

Neurotransmitter has a complimentary shape to thereceptors.The neurotransmitter molecules are then released from the axon terminals and into the synaptic cleft

At rest the outside of the membrane is +charged compared with the inside.The membrane is polarised.At rest – sodium ion channels in the membrane are closed. The resting potential and is -70mV

The molecules diffuse across the synapse (small gap between neurons) and then bind to the receptors of the next neuron's membrane.An action potential starts when a stimulus causes the membrane of one part of the axon to change in permeability. The inside of the neurone changes from -70mV to +40mV.

The Na ion channels of the receiving neuron open up, where sodium ions enter and cause depolarisationthat spreads down the neuron as a wave of depolarisation. The inside becomes positive compared to the outside.

.



Ion channel

Na+

transmitter

The ion channel closes, then releases the neurotransmitter which is now broken down

Finally, repolarization occurs, where the internal face of the membrane becomes negative again and the external becomes positive. During this step, potassium ion channels open to allow potassium to diffuse out.

- - - - - - - - - - - - -

+ + + + + + + + + + +

+ + + + + + + + + + +

K+

neurotransmitter molecules

The neurotransmitters must move very quickly! Or else, they will be removed from the synapse via diffusion.

dendrites

axon terminals

axon

myelin



Synapse (space between two neurons)

A nerve signal (action potential) travels through a neuron beginning at the dendrites, down the axon, and to the axon terminals. The membrane of the axon is polarized, meaning the external face is is positive and the internal is negative. Once the signal arrives, the membrane depolarizes, which is the opposite of polarization.

Neurotransmitter has a complimentary shape to thereceptors.The neurotransmitter molecules are then released from the axon terminals and into the synaptic cleft

At rest the outside of the membrane is +charged compared with the inside.The membrane is polarised.At rest – sodium ion channels in the membrane are closed. The resting potential and is -70mV

The molecules diffuse across the synapse (small gap between neurons) and then bind to the receptors of the next neuron's membrane.An action potential starts when a stimulus causes the membrane of one part of the axon to change in permeability. The inside of the neurone changes from -70mV to +40mV.

The Na ion channels of the receiving neuron open up, where sodium ions enter and cause depolarisationthat spreads down the neuron as a wave of depolarisation. The inside becomes positive compared to the outside.

.



Ion channel

Na+

transmitter

The ion channel closes, then releases the neurotransmitter which is now broken down

Finally, repolarization occurs, where the internal face of the membrane becomes negative again and the external becomes positive. During this step, potassium ion channels open to allow potassium to diffuse out.

- - - - - - - - - - - - -

+ + + + + + + + + + +

+ + + + + + + + + + +

K+

neurotransmitter molecules

The neurotransmitters must move very quickly! Or else, they will be removed from the synapse via diffusion.

dendrites

axon terminals

axon

myelin



Synapse (space between two neurons)

A nerve signal (action potential) travels through a neuron beginning at the dendrites, down the axon, and to the axon terminals. The membrane of the axon is polarized, meaning the external face is is positive and the internal is negative. Once the signal arrives, the membrane depolarizes, which is the opposite of polarization.

Neurotransmitter has a complimentary shape to thereceptors.The neurotransmitter molecules are then released from the axon terminals and into the synaptic cleft

At rest the outside of the membrane is +charged compared with the inside.The membrane is polarised.At rest – sodium ion channels in the membrane are closed. The resting potential and is -70mV

The molecules diffuse across the synapse (small gap between neurons) and then bind to the receptors of the next neuron's membrane.An action potential starts when a stimulus causes the membrane of one part of the axon to change in permeability. The inside of the neurone changes from -70mV to +40mV.

The Na ion channels of the receiving neuron open up, where sodium ions enter and cause depolarisationthat spreads down the neuron as a wave of depolarisation. The inside becomes positive compared to the outside.

.



Ion channel

Na+

transmitter

The ion channel closes, then releases the neurotransmitter which is now broken down

Finally, repolarization occurs, where the internal face of the membrane becomes negative again and the external becomes positive. During this step, potassium ion channels open to allow potassium to diffuse out.

- - - - - - - - - - - - -

+ + + + + + + + + + +

+ + + + + + + + + + +

K+

neurotransmitter molecules

The neurotransmitters must move very quickly! Or else, they will be removed from the synapse via diffusion.

dendrites

axon terminals

axon

myelin



Synapse (space between two neurons)

A nerve signal (action potential) travels through a neuron beginning at the dendrites, down the axon, and to the axon terminals. The membrane of the axon is polarized, meaning the external face is is positive and the internal is negative. Once the signal arrives, the membrane depolarizes, which is the opposite of polarization.

Neurotransmitter has a complimentary shape to thereceptors.The neurotransmitter molecules are then released from the axon terminals and into the synaptic cleft

At rest the outside of the membrane is +charged compared with the inside.The membrane is polarised.At rest – sodium ion channels in the membrane are closed. The resting potential and is -70mV

The molecules diffuse across the synapse (small gap between neurons) and then bind to the receptors of the next neuron's membrane.An action potential starts when a stimulus causes the membrane of one part of the axon to change in permeability. The inside of the neurone changes from -70mV to +40mV.

The Na ion channels of the receiving neuron open up, where sodium ions enter and cause depolarisationthat spreads down the neuron as a wave of depolarisation. The inside becomes positive compared to the outside.

.



Ion channel

Na+

transmitter

The ion channel closes, then releases the neurotransmitter which is now broken down

Finally, repolarization occurs, where the internal face of the membrane becomes negative again and the external becomes positive. During this step, potassium ion channels open to allow potassium to diffuse out.

- - - - - - - - - - - - -

+ + + + + + + + + + +

+ + + + + + + + + + +

K+

neurotransmitter molecules

The neurotransmitters must move very quickly! Or else, they will be removed from the synapse via diffusion.