The basic cell type of the nervous system is known as the _________.

• neurotransmitter

• synapse

• glial cell

• neuron

The part of a neuron that houses the nucleus is known as the ____________.

• axon

• dendrites

• cell body

• myelin

A benefit to a cell being myelinated is

• quicker transmission of messages

• insulation

• protection

• all of these are benefits

The direction for a nerve impulse is always:

• cell body - dendrites - axon

• dendrites - cell body - axon

• dendrites - myelin - axon

• axon - cell body - dendrites

Without calcium, what step would immediately not happen during an action potential?

• no sodium flooding the cell

• no charge reversal

• no neurotransmitters released from their vesicles

• no potassium leaving the cell

A positive charge within a neuron is a direct correlation to...

• calcium entering the axon terminal

• neurotransmitters floating across the synapse

• sodium entering the cell

• sodium/potassium pumps moving ions in and out of the cell

When the cell becomes hyperpolarized (dips beneath its resting membrane potential) this is because of...

• all the potassium ions leaving the cell

• the neurotransmitters flooding the synapse

• sodium entering the cell at a quick rate

• the neurotransmitters binding to their receptors

What step comes next:

Sodium enters the cell

• it then leaves through the sodium/potassium pumps

• the charge of the cell now changes to +30mV

• the charge of the cell drops, dipping beneath -70mV

• calcium releases neurotransmitters into synapse

What step comes next:

A message reaches the axon terminal

• this signals calcium to enter the terminal

• this depolarizes the cell

• this releases neurotransmitters into the synapse

• this reverses the charge of the cell

If the cell stayed at a charge beneath resting membrane potential, -70mV, then.....

• too much sodium would enter the cell

• neurotransmitters could not bond to their receptors

• potassium pumps would stop working

• the cell would be paralyzed - unable to accept another message

Tags

NGSS.HS-LS1-3