IB Bio Topic 7 Review

The long, fiber like part of a neuron which the cell sends information to receiving neurons

• axon

• dendrite

• axon terminal

• gene

A network of branches coming from individual cells. They carry information and electrical signals in the brain and nervous system

• axon

• axon terminal

• dendrite

• neuron

This insulating material forms a layer, around the axon of a neuron. It enables electrical signals to travel down the axon at higher speeds.

• neuron

• myelin sheath

• dendrite

• neurotransmitter

At resting potential, the ion distribution inside and outside of a neuron is such that __________ ions are most abundant on the outside of the cell, while __________ ions are most abundant on the inside of the cell.

• Potassium; sodium

• Sodium; potassium

• Calcium; potassium

• Calcium; sodium

In the figure above, what is occurring at step #4?

• Neuron receives enough stimulation, threshold is reached

• Na⁺ channels open allowing Na⁺ to diffuse inward, depolarizing the membrane

• K⁺ channels open and Na⁺ channels open, action potential begins

• K⁺ channels open allowing K⁺ to diffuse out, repolarizing the membrane

• Na⁺ are being pumped out and K⁺ are being pumped into the cell

What is structure labeled C in the picture?

• Dendrite
• Axon
• Cell Body
• Axon Terminal

What is structure labeled D in the picture?

• Dendrite
• Axon
• Cell Body
• Axon Terminal

What is structure labeled H in the picture?

• Nucleus
• Schwann Cell
• Node of Ranvier
• Myelin Sheath

Which number on the graph represents the Resting Potential?

• 1

• 2

• 3

• 4

• 5

When a neuron is depolarized, what are the first channels to open?

• Sodium channels

• Potassium channnels

• Sodium and potassium channels open at the same time

• Both sodium and potassium channels are already open, as it is passive transport