Perception Week 2: Action Potentials

How many of which ion does a sodium-potassium pump transfer when active?

• 3 sodium (Na+) IN and 2 potassium (K+) IN

• 3 sodium (Na+) IN and 2 potassium (K+) OUT

• 3 sodium (Na+) OUT and 2 potassium (K+) OUT

• 3 sodium (Na+) OUT and 2 potassium (K+) IN

Which direction does information move along a neuron?

• Dendrites -> Soma -> Axon

• Axon -> Soma -> Dendrites

• Soma -> Axon & Dendrites (both ways outward)

• Axon & Dendrites -> Soma (both ways inward)

Why does an action potential only move forward in one direction?

• Untrue: action potentials do propagate in two directions

• Because the K+ leak channels close after having been activated

• Because the voltage-gated Na+ become inactivated for a time after first closing

• Because the axon is shaped in a linear fashion

Which statement best describes how the nervous system communicates?

• Electrical signals within one neuron; chemical signals between neurons

• Electrical signals between neurons; chemical signals within one neuron

• Electrical signals both between neurons and within each neuron

• Chemical signals both between neurons and within each neuron

What does a myelin sheath do?

• Insulates axons; decreases the rate of ion movement

• Insulates axons; increases the rate of ion movement

• Conducts axons; increases the rate of ion movement

• Insults axons; says they're not good enough at being axons

When viewing this classic graph of an action potential, what is this really observing?

• One point in the axon over time

• The entire axon at one point in time

• The entire axon at all points in time

• Nothing during no points in time

Tags

NGSS.HS-PS2-5

During an action potential, between which two spaces are the charged particles (Na+ and K+) moved between?

• Inside the axon and inside the next (postsynaptic) cell

• Inside the axon and inside the soma (cell body)

• Inside the axon and outside the axon

• Inside the axon and inside the myelin sheath

If a pre-synaptic neuron fires an action potential, does that ALWAYS result in the post-synaptic neuron firing an action potential down the line in response?

• Yes

• No

What are the gaps between myelin sheath sections called?

• River Nodes

• Gap Junctions

• Nodes of Ranvier

• Nodes of Rivia

If I split these concepts into the below categories, which do you need more study time in?

• The bio/chem aspect of action potentials: ion movements, membrane channels, etc.

• The physiology aspect: Central vs. peripheral nervous system, types of cells, etc.

• The information processing aspect of neuron communication: pre/post synaptic neurons, direction of info, etc.

• No idea, all of it?

• Confident enough in most of it!