Understanding Neurons and Action Potentials

What is the basic building block of the nervous system?

• Neuron

• Axon

• Myelin

• Ion

What is the term used to describe the electrical impulse that occurs during the firing of neurons?

• Synaptic signal

• Action potential

• Ion exchange

• Neural impulse

What is the resting potential of an average neuron?

• -90 millivolts

• -30 millivolts

• -70 millivolts

• -50 millivolts

Which ions maintain the charge balance inside a neuron?

• Silicon, nitrogen, oxygen, hydrogen

• Zinc, copper, fluoride, carbon

• Magnesium, sulfur, iron, bromide

• Calcium, sodium, potassium, chloride

What happens when a neuron fires?

• Calcium channels open allowing calcium ions out

• Chloride channels close preventing chloride ions in

• Potassium channels open allowing potassium ions out

• Sodium channels open allowing sodium ions in

What is the all-or-none law in the context of neurons?

• Neurons fire randomly

• Neurons can fire at varying strengths

• Neurons always fire at full strength

• Only some neurons can fire

What is the refractory period of a neuron?

• A period when another action potential cannot occur

• A period of constant firing

• A period of decreased ion exchange

• A period when the neuron is hyperactive

What substance sheaths the axon to aid in electrical transmission?

• Elastin

• Myelin

• Keratin

• Collagen

Which disorder is associated with problems in the myelin sheath?

• Alzheimer's disease

• Multiple sclerosis

• Epilepsy

• Parkinson's disease

What is the role of potassium channels after a neuron fires?

• They reopen to help return the neuron to its resting potential

• They close to stop all ion movement

• They release potassium to the outside

• They initiate the firing of the neuron