Nervous System

Which numbers represents the neurons in a reflex arc?

• 3

• 4

• 5

• 7

Which numbers represents the motor neuron in a reflex arc?

• 3

• 4

• 5

• 7

A reflex performed __________ as an automatic response to a stimulus

• with conscious thought

• without conscious thought

• without a receptor

• without the central nervous

part of a neuron that receives information from other neurons

• axon
• dendrites
• myelin sheath
• synapse

a signal molecule that transmits nerve impulses across synapses

• neuron
• neurotransmitter
• nerve
• action potential

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

• Sodium
• Potassium
• Calcium
• ACTH

When a neuron is resting, the inside of the axon has a ____________ charge.

• positive
• negative

Which ions are involved in the electrical nerve impulse?

• Iodine and Sodium
• Potassium and Sodium
• Iron and Sodium
• Calcium and Iodine

What is the insulating membrane that surrounds parts of the axon that helps to protect & propagate action potential?

• Axon
• Dendrites
• Node of Ranvier
• Myelin Sheath

Depolarization occurs when

• sodium channels open

• potassium channels open

• sodium channels close

• potassium channels close