Neuroscience Neurons and Glial Cells

Questions and Answers

The glial cells that fight infections in the CNS are:

Microglia (correct)

Oligodendrocytes

Astrocytes

Satellite cells

Ependymal cells

Neurons that convey information to the CNS are called sensory or efferent neurons.

False

To perform their role, neurons must have the properties of excitability, secretion, and:

Stretchiness

Extensibility

Contractility

Elasticity

Conductivity (correct)

Neurons receive incoming signals by way of specialized extensions of the cell called:

Dendrites Signup and view all the answers

In the CNS myelin is produced by glial cells called Schwann cells.

False Signup and view all the answers

The absolute refractory period is a period of time in which a neuron is producing an action potential and cannot respond to another stimulus of any strength.

True Signup and view all the answers

A myelinated nerve fiber can produce action potentials only in specialized regions called nodes of Ranvier.

True Signup and view all the answers

Saltatory conduction occurs only:

In myelinated nerve fibers Signup and view all the answers

The highest density of voltage-gated ion channels is found on the ____ of a myelinated neuron:

Nodes of Ranvier Signup and view all the answers

Some neurotransmitters can be either excitatory or inhibitory depending on the type of:

Receptors on the postsynaptic cell Signup and view all the answers

An inhibitory postsynaptic potential is ____ of the postsynaptic neuron:

Hyperpolarization Signup and view all the answers

This is NOT a part of the peripheral nervous system:

Spinal cord Signup and view all the answers

This portion of the motor division of the nervous system conducts action potentials from the central nervous system to skeletal muscle fibers:

Somatic Signup and view all the answers

These cells conduct action potentials from one neuron to another within the CNS:

Interneurons Signup and view all the answers

These cell types produce and help circulate cerebrospinal fluid:

Ependymal cells Signup and view all the answers

These statements about unipolar neurons are all true except:

Located in the eye and nasal cavity Signup and view all the answers

This statement best describes the myelin sheath:

All true Signup and view all the answers

Compared to the outside of the resting cell membrane, the inside surface of the membrane is this:

Negatively charged Signup and view all the answers

Because of the sodium-potassium pump, there are:

More K+ inside the cell than outside and more Na+ outside the cell than inside Signup and view all the answers

During saltatory conduction action potentials jump from this:

One node of Ranvier to another Signup and view all the answers

This best describes the refractory period:

Both A and B Signup and view all the answers

Study Notes

Neurons and Glial Cells

Microglia are the glial cells responsible for fighting infections in the central nervous system (CNS).
Sensory neurons convey information to the CNS, while efferent neurons carry signals away from it.
Neurons must exhibit excitability, secretion, and conductivity to perform their functions.

Neuron Structure and Function

Dendrites are specialized extensions that receive incoming signals to a neuron.
Myelin in the CNS is produced by oligodendrocytes, not Schwann cells. Schwann cells are associated with the peripheral nervous system (PNS).
The absolute refractory period occurs when a neuron is generating an action potential and cannot respond to any stimulus.

Action Potentials and Conduction

Myelinated nerve fibers produce action potentials exclusively at the nodes of Ranvier.
Saltatory conduction occurs in myelinated fibers, allowing faster transmission of action potentials from one node of Ranvier to the next.
The highest density of voltage-gated ion channels is located at the nodes of Ranvier.

Neurotransmitters and Synapses

Some neurotransmitters have dual roles, acting as either excitatory or inhibitory based on the receptors present on the postsynaptic cell.
An inhibitory postsynaptic potential results in hyperpolarization of the postsynaptic neuron, making it less likely to fire.

Nervous System Divisions

The peripheral nervous system excludes the spinal cord, which is part of the central nervous system.
The somatic division of the motor nervous system carries action potentials from the CNS to skeletal muscles.

Neuron Types and Functions

Interneurons conduct action potentials between neurons within the CNS.
Ependymal cells produce and help circulate cerebrospinal fluid.
Unipolar neurons, mostly sensory, have a single process and are primarily located in regions such as the spinal cord, not typically in the eye or nasal cavity.

Myelin and Cell Membrane Properties

The myelin sheath, made of Schwann cells, covers axons, providing insulation and facilitating faster action potential conduction.
The interior of a resting cell membrane is negatively charged compared to the outside.
The sodium-potassium pump maintains a higher concentration of K+ ions inside the cell relative to Na+ ions outside.

Refractory Periods

The refractory period limits the number of action potentials produced over time and prevents immediate successive action potentials at the same membrane location.

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Description

Test your knowledge on the structure and function of neurons and glial cells. This quiz covers key concepts such as the roles of microglia, the function of sensory and efferent neurons, and the properties of action potentials. Perfect for students studying neurobiology.