Ch.12 AP Nervous Tissue

Which best describes an electrical potential? A form of potential energy that can produce current A positively or negatively charged atom or molecule The movement of charged particles like ions The opposition to the flow of electrical current across a membrane

A form of potential energy that can produce current

Which best describes signal conduction in unmyelinated axons?

A wave of depolarization opens more voltage-gated channels immediately distal to the action potential.

Choose all the ways neuromodulators alter synaptic transmission. Altering the breakdown and/or reuptake of neurotransmitter Adjusting the sensitivity of postsynaptic neurons to neurotransmitters Increasing the release of neurotransmitters by presynaptic neurons Promoting myelination by oligodendrocytes or Schwann cells

Altering the breakdown and/or reuptake of neurotransmitter. Adjusting the sensitivity of postsynaptic neurons to neurotransmitters. Increasing the release of neurotransmitters by presynaptic neurons.

Select all that are categories of neurotransmitters based on chemical composition. Sterols Amino acids Monoamines Acetylcholine Glycoproteins Neuropeptides

Amino acids Monoamines Acetylcholine Neuropeptides

Which term refers to the passage of proteins, organelles and other materials along an axon? Active transport Axonal transport Synaptic signaling Secretion

Axonal transport

Long-term potentiation may be involved in long-term memory. Choose all of the following that are molecular changes that occur in long-term potentiation. A decrease in the number of NMDA receptors Binding of glutamate to NMDA receptors The release of nitric oxide which triggers more glutamate release Entrance of calcium into the dendrite

Binding of glutamate to NMDA receptors The release of nitric oxide which triggers more glutamate release Entrance of calcium into the dendrite

What are the two major anatomical subdivisions of the nervous system?

Central and peripheral nervous systems

Choose all that would cause postsynaptic stimulation to end. Cessation of signals in the presynaptic nerve fiber Enzymatic degradation of neurotransmitter in the synaptic cleft Reuptake of neurotransmitter into the presynaptic knob Addition of receptors onto presynaptic membrane Diffusion of neurotransmitter from the synaptic cleft into extracellular fluid

Cessation of signals in the presynaptic nerve fiber. Enzymatic degradation of neurotransmitter in the synaptic cleft. Reuptake of neurotransmitter into the presynaptic knob. Diffusion of neurotransmitter from the synaptic cleft into extracellular fluid.

Which term refers to a synapse that releases acetylcholine from the presynaptic axon terminal?

Cholinergic

Which fundamental physiological property of neurons allows them to send signals quickly over long distances?

Conductivity

Choose all that are characteristics of local potentials. Decremental All-or-none Self-propagating Graded

Decremental Graded

The processes of a neuron that usually receive signals from other neurons are called

Dendrites

Choose all the factors that influence the speed of nerve signal conduction. Diameter of axon Presence of myelin Size of soma Type of neuron (multipolar vs. unipolar)

Diameter of axon Presence of myelin

In electrical synapses, electrical signals move quickly from cell to cell through which of the following?

Gap junctions

Short-term memory allows you to remember things for up to how long?

Hours

Which correctly describe axonal transport? It is a type of transport that occurs only in anaxonic neurons. It is bidirectional (retrograde and anterograde transport). It involves transport of proteins within the axon (i.e. synaptic knob enzymes or proteins that maintain the axolemma).

It is bidirectional (retrograde and anterograde transport). It involves transport of proteins within the axon (i.e. synaptic knob enzymes or proteins that maintain the axolemma).

Which of the following contributes to the development of the resting membrane potential in neurons? K+ is more concentrated in the ECF than in the ICF. K+ is more concentrated in the ICF than in the ECF. Na+ and K+ have equal concentrations on both sides of the membrane. Na+ is more concentrated in the ICF than in the ECF.

K+ is more concentrated in the ICF than in the ECF.

Which term refers to decremental changes in electrical potential along a dendrite or the soma?

Local potentials

Which term refers to decremental changes in electrical potential along a dendrite or the soma? Synaptic potentials Local potentials Action potentials Resting potentials

Local potentials

Which type of memory can store the most information?

Long-term

Which may be the basis for learning and long-term memory at the neuronal level?

Long-term potentiation

The ability of synapses to change is called synaptic plasticity. Which term refers to the neuronal pathways formed during learning?

Memory traces

Choose the three functional classes of neurons.

Motor neurons Interneurons Sensory neurons

Which two organ systems are primarily responsible for coordinating the other bodily systems so as to maintain homeostasis?

Nervous system Endocrine system

Which term describes the ability of neurons to process information, store and recall it, and make decisions?

Neural integration

Which alter synaptic transmission by adjusting the sensitivity of postsynaptic neurons to neurotransmitters or by affecting the breakdown and/or removal of a neurotransmitter?

Neuromodulators

Stimulation of the postsynaptic neuron will end when nerve signals stop arriving at the presynaptic axon terminal or when which of the following occurs?

Neurotransmitter is removed from postsynaptic receptors.

Choose all that are properties of action potentials. Nondecremental (signal maintains amplitude) Self-propagating Graded (amplitude proportional to stimulus strength) All or none

Nondecremental (signal maintains amplitude) Self-propagating All or none

Taken together, the sensory and motor subdivisions make up which of the following?

Peripheral nervous system

Neural integration is based on the combining together of which of the following?

Postsynaptic potentials

Which ion has the greatest influence on the resting membrane potential of most neurons?

Potassium

Choose all that are types of long-term memory? Procedural Working Immediate Declarative

Procedural Declarative

Which term refers to the period of time after a nerve cell has responded to a stimulus in which it cannot be excited by a threshold stimulus?

Refractory period

Which type of glial cell aids in regeneration of damaged peripheral nerve fibers by forming a regeneration tube to help reestablish the former connection?

Schwann cells

The release of a neurotransmitter is an example of which physiological property exhibited by a neuron?

Secretion

Which is true about a neuron with a large diameter, myelinated axon as compared to a neuron with a small diameter, unmyelinated axon?

Signal conduction will be faster

Choose all that are names for the cell body of a neuron.

Soma Neurosoma

The sensory and motor divisions of the peripheral nervous system are further split into which two subdivisions?

Somatic and visceral

Which term refers to the microscopic physical gap between the presynaptic and postsynaptic neurons at a chemical synapse?

Synaptic cleft

Choose all statements that are true regarding postsynaptic potentials? They are caused by neurotransmitters. They depend on the myelination of nerve axons. They are changes in the membrane potential of the postsynaptic terminal of a chemical synapse. They include EPSPs and IPSPs.

They are caused by neurotransmitters. They are changes in the membrane potential of the postsynaptic terminal of a chemical synapse. They include EPSPs and IPSPs.

Choose all statements that are true about Schwann cells? They assist in the regeneration of damaged nerve fibers. They form the myelin sheath in the PNS. They are only found in the central nervous system. They form the neurilemma.

They assist in the regeneration of damaged nerve fibers. They form the myelin sheath in the PNS. They form the neurilemma.

Choose all the statements that characterize neurotransmitters? They are found in dendrites of postsynaptic neurons. They bind to receptors and alter the physiology of the postsynaptic cell. They are released in response to stimulation. They stimulate the opening of voltage-regulated gates at the postsynaptic membrane. They are synthesized by presynaptic neurons.

They bind to receptors and alter the physiology of the postsynaptic cell. They are released in response to stimulation. They are synthesized by presynaptic neurons.

Choose all that are characteristics of neural pools. They classify neurons based on shape. They consist of complex patterns of interneurons. They may be concerned with a particular body function. They consist of sensory neurons that synapse directly onto motor neurons.

They may be concerned with a particular body function. They consist of complex patterns of interneurons.

Choose all that are characteristics of neuroglia: Multiple select question. They protect the neurons and help them function. They are less numerous than neurons. Their main properties are excitability and conductivity. They bind neurons together and provide a supportive scaffold.

They protect the neurons and help them function. They bind neurons together and provide a supportive scaffold.

Why would the synapses of a memory trace undergo synaptic potentiation?

To allow easier signal transmission along pathway

Which lists the structural categories of neurons?

Unipolar, bipolar, anaxonic, and multipolar

An axon lacking a myelin sheath is said to be what?

Unmyelinated

Choose all of the following statements that are true about signal conduction along unmyelinated fibers. Unmyelinated fibers have voltage-gated channels along their entire length. The signal conduction in unmyelinated fibers is saltatory. A zone of depolarization excites voltage-gated channels immediately distal to the action potential.

Unmyelinated fibers have voltage-gated channels along their entire length. A zone of depolarization excites voltage-gated channels immediately distal to the action potential.

The refractory period in which no stimulus of any strength will trigger a new action potential is the ______ refractory period.

absolute

A cholinergic synapse uses which of the following as its neurotransmitter? Norepinephrine Serotonin Endorphin Acetylcholine

acetylcholine

In a synapse, where are synaptic vesicles located?

axon terminal

The brain and spinal cord are components of the ______ nervous system, while the nerves and ganglia are components of the ______ nervous system.

central, peripheral

The processes that branch from the somas of most neurons are called ______.

dendrites

The soma of a neuron gives rise to branch-like processes called what? They are the primary sites for receiving signals from other neurons.

dendrites

Two organ systems are dedicated to internal coordination, communication between the other systems, and maintaining the overall homeostasis of the body. They are the ______ which communicates by means of hormones, and the ______ which sends quick electrical and chemical messages from cell to cell.

endocrine, nervous

True or false: Damaged nerve fibers in the CNS regenerate very fast whereas damaged nerve fibers in the PNS never regenerate.

false

True or false: The more synapses a neuron has, the lesser its information-processing capability.

false

______ cells protect the neurons and help them function.

glial

The myelin sheath is a spiral layer of ______ around a nerve fiber.

insulation

The myelin sheath is composed mostly of which of the following?

lipids

Declarative and procedural memory are two types of what?

long term memory

Synapses are not fixed for life. In response to experience, they can be modified to make transmission easier or harder. The ability of synapses to change is called synaptic _______

plasticity

At a synapse, the neuron that responds to the neurotransmitter is the ______ neuron.

postsynaptic

An electrical potential is a form of what type of energy?

potential energy

Synapses in a certain pathway can be modified to allow signals to travel more easily across "trained" synapses. Which term refers to the process of making transmission easier?

potentiation

At a synapse, the neuron that releases neurotransmitter is the ______ neuron.

presynaptic

What is the role of neural pools in the CNS?

process information

The refractory period in which it is possible to trigger a new action potential, but only with an unusually strong stimulus is the ______ refractory period. absolute relative

relative

Which neuroglial cell is found in the peripheral nervous system?

satellite cell

Identify the type of cell indicated by the arrow labeled A.

schwann cell

Which type of glial cell produces the myelin sheath in the PNS?

schwann cell

Afferent neurons are what type of neurons? Sensory or Motor?

sensory neurons

This picture illustrates a phenomenon that occurs in the trigger zone when multiple postsynaptic potentials combine their effects on a cell to produce a response. What is it called?

summation

Which division inhibits digestion?

sympathetic

The autonomic nervous system is subdivided into the ______ division which tends to arouse the body for action and the ______ division which tends to have a calming effect.

sympathetic, parasympathetic

At its distal end, an axon has an extensive complex of fine branches called what?

terminal arborization

True or false: Action potentials occur only where there are voltage-gated ion channels.

true

True or false: Unmyelinated nerve fibers (axons) in the PNS are enveloped in Schwann cells.

true

Together, the sympathetic and parasympathetic nervous systems make up the entirety of which division of the nervous system?

visceral motor division