IB: Nervous System & Movement

What is the smallest structural (functional) unit of the nervous system?

• neuron

• glial cell

• nerve

• neurotransmiter

What is the function of an interneuron?

• detects stimulus such as light, sound, smell

• transmit impulse from CNS to muscle or gland cell

• process information received

• none of the above

A stimulus is received by a neuron in which structure?

• cell body

• synaptic bulb

• dendrites

• axon

Which of the following is NOT a glial cell?

• astrocyte

• interneuron

• oligodendrocyte

• schwann cell

Which way do ions move in an action potential?

• Ca+2 and Na+ move into the neuron & K+ moves out

• Na+ moves in and K+ moves out of the neuron

• Na+ and K+ move into the neuron

• Na+ moves out and K+ moves into the neuron

Why does it hurt more when someone pinches you with more force?

• the action potential signal is big

• the frequency of action potentials decreases

• the action potential signal is smaller

• the frequency of action potentials increases

What happens to cause a cell to be depolarized?

• K+ channels open

• Cl- channels open

• Na+ channels open

• Both Na+ and K+ movement result in depolarization of a cell

For a neuron at rest, if a neurotransmitter causes Cl- ion channels to open at the dendrites and Cl- ions enter the cell, how will the membrane potential be affected?

• depolarized

• repolarized

• hyperpolarized

• no change in membrane potential

TRUE or FALSE: The neuron membrane is slightly permeable to Na+ and it can leak through.

• TRUE

• FALSE

Axons that are myelinated...

• have local currents

• have fewer action potentials

• pass messages faster

• All of the above