Exam 8: Neurons: Cellular and Network Properties

Match the term with its description (answers may be used more than once). -cells that create a selectively permeable epithelial layer to separate fluid compartments of the CNS

In the first phase of triggering an action potential in a neuron, Na⁺ ions flow in and

Match the part of the neuron to its description (answers may be used more than once). -may be covered with myelin

If a stimulating electrode is placed in the middle of a resting axon and an above-threshold voltage is applied to the electrode action potentials

Match the term with its description (answers may be used more than once). -specialized immune cells that are confined to the CNS

Match the term with its description (answers may be used more than once). -cells that myelinate only one axon each; multiple cells per axon

The brain and spinal cord together compose the

The term hyperkalemia specifically indicates too much potassium in which fluid compartment?

The ________ principle states that the properties of the action potential are independent of the relative strength of the depolarizing stimulus.

Draw a graph showing what would happen to resting membrane potential over time, if the sodium/potassium pump were not functioning.How would this affect a neuron's ability to produce action potentials? What does this imply about the quantity of ions that normally cross the membrane during the course of an action potential?

If both Na⁺ and K⁺ channels are activated by depolarization, why do we see more Na⁺ flux during the rising phase of an action potential?

Match the term with its description (answers may be used more than once). -cells that are a source of neural stem cells

Briefly explain the gross organization of the nervous system in either paragraph form or using a concept map.Be sure to discuss the central, peripheral, and enteric nervous system and the divisions and branches discussed in the text.

Tetrodotoxin is a toxin that blocks voltage-gated sodium channels.What effect does this substance have on the function of neurons?

Match the part of the neuron to its description (answers may be used more than once). -occupy(ies)the least amount of cell volume

Some neurotoxins work essentially the same way as some local anesthetics, which is to

When multiple, possibly even conflicting signals reach a neuron, the neuron evaluates the signals and may respond or not.This property is called

Match the type of signal to its description (answers may be used more than once). -size increases if stimulus strength increases

During the relative refractory period, an initial threshold-level depolarization is usually not sufficient to trigger an action potential.Why?

If a hyperpolarizing graded potential and a depolarizing graded potential of similar magnitudes arrive at the trigger zone at the same time, what is most likely to occur?