Neuron Communication Quiz

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Questions and Answers

What is the primary function of dendrites in a neuron?

To process and integrate information

To receive incoming signals (correct)

To transmit information to neighboring neurons

To carry information over long distances

What occurs when a neuron reaches the threshold of -55 millivolts?

The neuron ceases all activity

The neuron achieves resting potential

The neuron starts releasing neurotransmitters

The neuron transmits an action potential (correct)

What is the resting potential of a typical neuron?

-70 millivolts (correct)

+10 millivolts

-100 millivolts

0 millivolts

How is information coded within the nervous system?

Using action potentials of fixed size and shape Signup and view all the answers

What is the main reason for the chemical nature of synaptic transmission?

To facilitate the movement of neurotransmitters between neurons Signup and view all the answers

What do excitatory signals mainly influence in a neuron?

The generation of action potentials Signup and view all the answers

What role do ions play in the generation of action potentials?

They generate electrical signals by moving across the membrane Signup and view all the answers

What is an action potential characterized by?

A rapid change in membrane potential that propagates along the axon Signup and view all the answers

What is the primary voltage of a neuron at rest?

-70 mV Signup and view all the answers

Which ion is more concentrated outside of the neuron at rest?

Sodium (Na+) Signup and view all the answers

Which mechanism helps to maintain the resting membrane potential of -70 mV despite ion movement?

A combination of diffusion, electrostatic pressure, and transporters Signup and view all the answers

What does the sodium-potassium pump do?

Pumps potassium ions into the cell and sodium out Signup and view all the answers

What role does electrostatic pressure play in ion movement across the cell membrane?

It prevents negative ions from entering the cell Signup and view all the answers

How does diffusion contribute to ion movement in the neuron?

It moves ions from high to low concentration without energy Signup and view all the answers

What happens to potassium ions (K+) at the resting membrane potential?

They are unable to leave the cell due to electrostatic pressure Signup and view all the answers

What energy source is used by the sodium-potassium pump to operate?

ATP Signup and view all the answers

Study Notes

Neuron Communication

Neuron Anatomy:
- Dendrites: Receive incoming signals.
- Cell Body: Processes and integrates information.
- Axon: Carries information over long distances.
- Axon Terminal: Transmits information to the next cell.
Action Potential:
- A neuron transmits a signal along the axon if incoming stimulation is strong enough.
- The neuron "fires."
- Electrical signals are fast for immediate reactions.
- Inside of a neuron is more negative than outside.
- Information in the brain is coded through action potentials (electrical impulses).
- Action potentials are all the same size and shape.
- Differences are in the firing frequency (higher or lower).
- Action potentials regenerate at each node.
Synaptic Communication:
- Synapses are chemical, not electrical.
- Communication occurs between two neurons.
- Threshold of activation is -55mV for an action potential.
- Action potentials carry information through impulses.
- Outside the neuron has no electricity. No AP outside.
Electrical Signals & Ions:
- Electrical signals inside neurons are called action potentials.
- Start in dendrites, end at terminals.
- Signals are from ion flow (atoms with charges).
- Ions are atoms or groups carrying a charge (positive or negative) from gaining/losing electrons.
- Inside of neuron is more positively charged than outside.

Membrane Potential

Membrane Potential: Difference in charge between inside and outside the cell.
Resting Potential: Approximately -70 mV (neuron is "at rest").
Electrochemical Gradient: A combination of chemical (concentration) and electrical (charge) gradients.

Electrical Excitability

Resting Membrane Potential: The neuron's potential when not transmitting information (maintains a state for rapid response to stimuli).
Action potential depends on resting membrane potential - maintains -70 mV for quick actions potentials.
Electrical excitability is due to the neuron's ability to maintain a potential that facilitates fast action potentials. The brain uses 20% of body energy.
Resting membrane potential is -70 mV.

Maintaining Resting Potential

3 Mechanisms (continuous ion movement):
- Diffusion: Natural movement from high to low concentration. Sodium and Potassium move oppositely, based on concentration differences. Chloride moves towards negative charges if possible. Requires no energy (passive).
- Electrostatic Pressure: Positive charges are pushed away from positive charges; negative charges attract negative charges. Attracts/repel charges based on the relative polarity. Requires no energy (passive).
- Transporters: Active transport that uses ATP (energy) to move substances AGAINST their concentration gradient. This ensures the neuron remains at its negative resting potential. Specifically, the sodium-potassium pump maintains the gradient by moving sodium out and potassium into the cell.

Ion Concentrations

Sodium (Na+):
- More sodium outside of the neuron than inside
- Positive charge
Potassium (K+):
- More potassium inside of the neuron than outside
- Positive charge
Chloride (Cl-):
- More chloride outside of the neuron than inside
- Negative charge
Polarized State:
- Inside of a cell is negative, outside is positive.
- Cell membrane is permeable to positive ions more than others due to negative interior. Neuron maintains -70 mv resting potential

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Description

Test your knowledge on neuron anatomy, action potentials, and synaptic communication. Understand the processes that allow neurons to transmit signals and how information is coded in the brain. This quiz covers essential concepts necessary for grasping how neurons interact and communicate effectively.