cns

What do myelin sheath membranes lack that makes them good insulators?

Channel and carrier proteins

Which statement below most accurately describes the function of oligodendrocytes?

Form the myelin sheath in the CNS

Gray matter primarily contains ________________.

neuron cell bodies

Which statement below most accurately describes the function of microglial cells?

Phagocytic cells of the CNS

Which of the following statements accurately defines Node of Ranvier?

Spaces between segments of the myelin sheath

What would result from inhibition of a neuron's sodium-potassium pump?

The membrane would lose its polarity.

Which of the following statements accurately defines cell body?

The biosynthetic center of the neuron

The Na+/K+ pump operates by pumping _______________ ions out of the cell while pumping ________ ions into the cell.

3 Na+, 2 K+

Which of the following statements accurately defines myelin sheath?

A fatty sheath found around certain axons that increases the speed of conduction of an action potential

Which of the following statements accurately defines dendrite?

Branching process of the neuron that transmits electrical potentials toward the cell body

Which of the following statements accurately defines synaptic cleft?

Fluid-filled space at a synapse through which neurotransmitters diffuse

Which of the following cells is responsible for myelin formation in the central nervous system?

Oligodendrocytes

Which statement below most accurately describes the function of satellite cells?

Surround the cell bodies of neurons in the PNS

An IPSP is associated with _____________.

the opening of chemically gated channels for K+ hyperpolarization reduced excitability depolarization Correct! A, B, and C

Sensory neurons ______________.

transmit impulses to the brain and spinal cord

Impulse propagation is associated with __________________.

voltage-gated sodium channels

____________ neurons function as sensory neurons.

Unipolar Bipolar Multipolar Efferent Correct! A and B

Which of the following is involved with a positive feedback cycle?

Voltage-gated sodium channels

If the following receptors were stimulated simultaneously, which signal would reach the brain first?

Pressure receptors found in the toe's musculature

Which of the following statements accurately defines axon terminal?

Swollen area found at the end of each telodendrion that contains synaptic vesicles

Which of the following statements accurately defines neuron?

The cells of nervous tissue that generate and transmit action potentials

Which of the following statements accurately defines synaptic vesicle?

A vesicle containing neurotransmitters in the axon terminal of a neuron

The main function of an axon is to

generate and transmit signals in the form of action potentials.

An inhibitory neuron could affect the neuron with which it synapses by _______________.

producing an IPSP within the neuron hyperpolarizing the neuron increasing K+ efflux from the neuron increasing Cl- influx into the neuron Correct! All of the above

A neuron that excites skeletal muscle cells in your biceps muscles is functionally a(n) _________ neuron and structurally a(n) ______ neuron.

sensory, bipolar

Neurons that reside entirely within the CNS are _______ neurons. Structurally, most of these neurons belong to the ______ classification.

sensory, unipolar

Hyperpolarization results from _________________.

sodium flux into the cell chloride flux into the cell potassium flux into the cell potassium flux out of the cell Correct! B and D

Which statement below most accurately describes the function of astrocytes?

Anchor neurons and blood vessels, maintain extracellular environment around neurons, assist in the formation of the blood-brain barrier

Axons within nerves may have which of the following associated with them?

Schwann cells Nodes of Ranvier Oligodendrocytes Correct! A and B

Which of the following statements accurately defines postsynaptic neuron?

The neuron that receives the message; its plasma membrane contains receptors for neurotransmitters

Which of the following statements accurately defines presynaptic neuron?

The neuron that sends the message; its axon terminals contain synaptic vesicles with neurotransmitters

Which statement below most accurately describes the function of Schwann cells?

Create the myelin sheath in the PNS

Positively charged ions are known as _____________, whereas negatively charged ions are known as _________.

cations, anions

Which of the following statements accurately defines axon?

Process of the neuron that generates and transmits action potentials

Which of the following organelles is responsible for the appearance of Nissl bodies in the cell bodies of motor neurons?

Rough endoplasmic reticulum

A neuron with many short dendrites and a single long axon is a _______________.

multipolar neuron

Which is not a characteristic of a chemical synapse?

Abundant gap junctions

Where are synaptic vesicles located?

Axon terminals.

Which of the following statements accurately defines neuroglial cell?

Cells of nervous tissue that surround and support neurons

Which statement below most accurately describes the function of ependymal cells?

Ciliated cells in the CNS that form and circulate cerebrospinal fluid

Which of the following statements accurately defines synapse?

Junction between neurons and target cells

Which of the following would be a direct result of destruction of a neuron's neurofilaments?

Loss of normal cell shape