The Brain and Nervous System

Questions and Answers

Which type of cells make up the nervous system?

Neurons and glia

What is the role of glia in the nervous system?

To provide support functions for neurons

What are the four major types of neurons?

Unipolar, bipolar, multipolar, and pseudounipolar

What causes the resting membrane potential of a neuron?

Differences in ion concentrations inside and outside the cell Signup and view all the answers

What are action potentials?

Brief reversals of the resting membrane potential that allow transmission of a signal within a neuron Signup and view all the answers

What is the refractory period?

The time period during which a neuron cannot produce another action potential Signup and view all the answers

What happens during the refractory period?

Voltage-gated K+ channels open, allowing K+ to leave the cell and repolarize the membrane Signup and view all the answers

What is the role of glia in myelination of axons?

Glia produce myelin sheaths around axons Signup and view all the answers

What happens once the threshold potential is reached in a neuron?

The neuron always completely depolarizes Signup and view all the answers

What can be the effect of malfunctioning glia on the brain?

Tumors can be caused by mutations in glia Signup and view all the answers

Study Notes

The nervous system controls all behaviors and bodily functions.
Invertebrate and vertebrate nervous systems vary in structure and complexity.
Neurons and glia are the two types of cells that make up the nervous system.
Neurons are specialized cells that receive and transmit signals.
Neurons have different types and shapes that relate to their functional roles.
Glia provide support functions for neurons and outnumber them in the brain.
There are four major types of neurons: unipolar, bipolar, multipolar, and pseudounipolar.
Glia guide developing neurons, buffer ions and chemicals, and provide myelin sheaths around axons.
Glia also play a role in responding to nerve activity and modulating communication between nerve cells.
Malfunctioning glia can have disastrous effects on the brain.
Tumors are caused by mutations in glia.
Neurons communicate through electrical and chemical signals.
Neurons have a charged cellular membrane that can change in response to neurotransmitters.
The resting membrane potential of a neuron is caused by differences in ion concentrations inside and outside the cell.
Potassium ions dominate the resting membrane potential of a neuron.
Action potentials are brief reversals of the resting membrane potential that allow transmission of a signal within a neuron.
Action potentials are an "all-or-nothing" event and once the threshold potential is reached, the neuron always completely depolarizes.
The refractory period follows an action potential and the neuron cannot produce another action potential during this time.
Voltage-gated K+ channels open during the refractory period, allowing K+ to leave the cell and repolarize the membrane.
Eventually, all the K+ channels close and the cell returns back to its resting membrane potential.