Lecture Exam 2 Flashcards
(14 cards)
What do neurons use to transmit information?
Neurons transmit information via electrical signals that depend on the membrane potential.
What is the typical resting membrane potential (RMP) for a neuron?
The typical RMP for a neuron is around -70mV.
What maintains the resting membrane potential?
The RMP is maintained by sodium-potassium pumps and potassium leak channels.
How do sodium-potassium pumps function?
Sodium-potassium pumps actively transport 3 Na⁺ ions out of the cell and 2 K⁺ ions in, using ATP.
What is the role of potassium leak channels?
Potassium leak channels allow K⁺ to flow out of the cell, contributing to the negative charge inside the neuron.
What effect do sodium leak channels have on RMP?
A small number of sodium leak channels allow Na⁺ to slowly enter the cell, slightly affecting the RMP.
What are the two types of changes in membrane potential?
The two types of changes are depolarization and hyperpolarization.
What occurs during depolarization?
During depolarization, the inside of the neuron becomes less negative, reducing the difference between the inside and outside.
What occurs during hyperpolarization?
During hyperpolarization, the inside of the neuron becomes more negative, increasing the charge difference.
What are graded potentials?
Graded potentials are small, local changes in the RMP that occur mainly in the dendrites and cell body.
How do excitatory postsynaptic potentials (EPSPs) occur?
EPSPs occur when a neurotransmitter binds to a receptor, opening chemically-gated ion channels and allowing Na⁺ to enter the cell.
What are action potentials?
Action potentials are large, rapid depolarizations that can travel long distances down the axon.
What initiates an action potential?
An action potential is initiated when a threshold potential is reached, typically at the axon hillock.
How do graded potentials and action potentials differ?
Graded potentials initiate localized changes, while action potentials enable long-range signal transmission along the axon.
