Neurons Flashcards
Q: What is a neuron?
A: A neuron is a specialized cell in the nervous system that transmits electrical impulses. It is made up of the cell body, dendrites, and an axon.
Q: What are the main parts of a neuron?
A: The main parts of a neuron are the dendrites, cell body (soma), axon, and axon terminals.
Q: What is the function of dendrites?
A: Dendrites receive signals from other neurons and transmit them to the cell body.
Q: What is the role of the axon?
A: The axon transmits electrical impulses away from the cell body to other neurons or muscle cells.
Q: What is the synapse?
A: The synapse is the gap between two neurons where neurotransmitters are released to transmit signals.
Q: What happens at the synapse?
A: At the synapse, neurotransmitters are released from the axon terminal of one neuron and bind to receptors on the dendrites of the next neuron to transmit the signal.
Q: What are neurotransmitters?
A: Neurotransmitters are chemicals that transmit signals across the synapse from one neuron to another or to a target cell.
Q: What is the action potential?
A: The action potential is a rapid electrical signal that travels down the axon of a neuron. It occurs when the neuron’s membrane potential becomes more positive, reaching a threshold that triggers an impulse.
Q: What causes an action potential to occur?
A: An action potential occurs when sodium ions (Na+) rush into the neuron, causing a depolarization of the membrane. This is followed by potassium ions (K+) exiting the neuron to restore the resting potential.
Q: What is depolarization?
A: Depolarization is the process by which the inside of a neuron becomes more positive, typically caused by the influx of sodium ions during an action potential.
Q: What is repolarization?
A: Repolarization is the process by which the neuron’s membrane potential returns to its resting state, mainly through the exit of potassium ions after an action potential.
Q: What is the role of the myelin sheath in action potentials?
A: The myelin sheath insulates the axon, speeding up the transmission of the action potential by allowing it to jump from node to node (saltatory conduction).
Q: What is the resting membrane potential of a neuron?
A: The resting membrane potential is the electrical charge difference across a neuron’s membrane when it is not transmitting an impulse, typically around -70mV.
Q: What happens during the refractory period?
A: During the refractory period, the neuron cannot generate another action potential immediately after one has passed, allowing it time to reset before firing again.
Q: What is the role of sodium-potassium pumps in neurons?
A: Sodium-potassium pumps help maintain the resting membrane potential by actively transporting sodium ions out of the neuron and potassium ions into the neuron, contributing to the electrical gradient.
