Nervous System I

Nervous System I: Ion Channels - Self Test

NOTE: This quiz is designed to be completed using the InteractivePhysiology CD that you used in the Muscle Lab. However, you should be able to answer most of the questions without the CD by using your class notes and your textbook.

1. What kinds of structures in the cell membrane function as ion channels?

2. Ion channels are selective for specific ions. What three characteristics of
the ions are important for this selectivity?

3. Channels can be classified as either active or passive channels. A sodium channel
that is always open would be classified as a/an ________________________ channel.

4. Would sodium ions move into or out of the neuron through the channels in question 3? _______________

5. Voltage-gated potassium channels open at what voltage? __________ mV

6. Acetylcholine (ACh) and GABA are neurotransmitters that open chemically-gated
channels. What ions pass into the cell when these channels are activated?

a. ACh: ________________________ ions

b. GABA: ________________________ ions

7. Ion channels are regionally located and functionally unique. List all the areas on the neuron and the type of potential dependent on the following types of ion channels:

a. Passive (leak) channels -

b. Chemically-gated channels -

c. Voltage-gated channels -

8. From the quiz, place an "X" by the characteristics of voltage-gated sodium channels.

Always open

Found along the axon

Important for action potential

Opened and closed by gates

Found on the dendrites and cell bodies

Important for resting membrane potential

9. Name two types of channels (active or passive) through which chloride ions could pass into the cell.