A&P Ch 12

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

presynaptic

The nervous system plays an important role in maintaining homeostasis. List, in order, the basic steps that describe how the nervous system carries out this task. Instructions

1. Information received by sensory receptors is transmitted to the CNS.2. Information is processed and an appropriate response is determined.3. A command is issued to effectors such as muscles or glands.

Click and drag on elements in order Starting with a signal reaching the distal end of the presynaptic axon, indicate the correct order of events that occur during transmission at a cholinergic excitatory synapse. Instructions

1. Opening of calcium gates in synaptic know as nerve-signal arrives2. Exocytosis of ACh; diffusion across synaptic cleft3. Binding of ACh to receptors on postsynaptic neuron4. Opening of sodium gates on post-synaptic membrane allowing influx of sodium5. Depolarization of postsynaptic plasma membrane

Select all that apply Which types of glial cells are found in the central nervous system?

Astrocytes Microglia Ependymal cells Oligodendrocytes

Which process of a neuron is specialized for rapid conduction of nerve signals to structures relatively far away from the neuron cell body?

Axon

Match the following terms with their description. Axon hillock- Axoplasm- Axolemma- Axon collateral-

Axon hillock-Branch that originates from an axon Axoplasm-Plasma membrane of the axon Axolemma-Cytoplasm of the axon Axon collateral-A mound located on one side of the soma from which the axon originates

Which term applies to the small swellings at the distal end of the axon of a neuron that contain synaptic vesicles?

Axon terminals

Tetanic stimulation at a synapse is due to accumulation of which of the following in the synaptic terminal?

Calcium

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

Conductivity

Select all that apply Which are the principal types of neural circuits?

Converging circuit Reverberating circuit Parallel after-discharge circuit Diverging circuit

Select all that apply Which are characteristics of local potentials?

Decremental Graded

are the processes of a neuron that usually receive signals from other neurons.

Dendrites

Select all that apply Which would cause postsynaptic stimulation to end?

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

Select all that apply Long-term potentiation may be involved in long-term memory. The molecular changes that occur in long-term potentiation include which of the following?

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

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: Electrical synapses are able to integrate information and make decisions more rapidly than chemical signals.

False

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

False

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

Gap junctions

Which type of memory is important as you read (e.g. remembering the previous words in a sentence)?

Immediate

Select all that apply Which correctly describe axonal transport?

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 ICF than in the ECF.

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

Lipids

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

Local potentials

Which type of memory can store the most information?

Long-term

Declarative and procedural memory are two types of what?

Long-term memory

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

Long-term potentiation

Neurons with numerous dendrites and a single axon are structurally classified as which of the following?

Multipolar

Neurons are classified structurally according to the number of processes extending from the soma. Match each classification to its description. Multipolar Neurons- Bipolar Neurons- Unipolar Neurons- Anaxonic Neurons-

Multipolar - One axon, multiple dendrites Bipolar - One axon, one dendrite Unipolar - A single process Anaxonic - No axon, multiple dendrites

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

Nervous system Endocrine system

The pathway of neurons within a neural pool is called its what?

Neural circuit

This picture illustrates that when a stimulus strength (weight) and stretch increase at a sensory fiber, the firing frequency of the neurons increase. Which term refers to the conversion of stimulus information into a meaningful pattern of action potentials?

Neural coding

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.

Select all that apply Which are usually found inside the cell body (or soma) of a mature neuron?

Nucleus Rough endoplasmic reticulum Mitochondria

Which type of glial cell is indicated by the arrow labeled A?

Oligodendrocytes

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

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

Select all that apply Which factors influence the speed of nerve signal conduction?

Presence of myelin Diameter of axon

Select all that apply Which 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

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

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

Synaptic cleft

What type of stimulation is caused by rapid, repetitive signals arriving at a synaptic knob, causing progressively larger quantities of calcium to accumulate and leading to synaptic facilitation?

Tetanic

Select all that apply Which statements are true regarding postsynaptic potentials?

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.

Select all that apply Which statements characterize neurotransmitters?

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

Select all that apply Which are characteristics of neural pools?

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

Select all that apply Which statements are true about Schwann cells?

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

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

To allow easier signal transmission along pathway

What is the primary function of the myelin sheath?

To increase the speed of signal conduction in the axon

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

True

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 nervous system must interpret quantitative and qualitative information about its environment, thus it converts information to a meaningful pattern of action potentials. This process is called neural .

coding

The picture shows the most common structural type of neuron. It contains one axon and multiple dendrites, and it is classified as a(n) ______ neuron.

multipolar

The neurons indicated by a letter "A" are structurally classified as ______ neurons. The neurons indicated by a letter "B" are structurally classified as ______ neurons.

multipolar, bipolar

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

In a chemical synapse, synaptic vesicles full of neurotransmitter are docked at release sites on the membrane of the presynaptic neuron, while neurotransmitter receptors are found on the membrane of the neuron.

postsynaptic

Afferent neurons are ______ neurons.

sensory

Sensory (afferent) neurons do which of the following?

Carry signals to spinal cord and brain

List the fundamental physiological properties of neurons.

Excitability, conductivity, secretion

This picture illustrates neural transmission at which type of synapse?

Excitatory cholinergic synapse

______ cells protect the neurons and help them function.

Glial

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

Select all that apply Which are types of long-term memory?

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

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

Schwann cell

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

Select all that apply Which are properties of action potentials?

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

Select all that apply List the three functional classes of neurons.

Sensory neurons Motor neurons Interneurons

Which type of memory allows you to remember things from up to a few hours ago?

Short-term

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

Which part of the neuron is indicated by the arrow labeled A?

Terminal arborization

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

oligodendrocytes

There are two ways in which EPSPs can add up to produce enough activity to make a postsynaptic cell fire. They are temporal and spatial .

summation

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 a(n) ______.

terminal arborization

An axon lacking a myelin sheath is said to be ______.

unmyelinated

Which term refers to the passage of proteins, organelles and other materials along an axon?

Axonal transport

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

Cholinergic

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

Memory traces

Select all that apply Choose the characteristics of neuroglia.

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

What is the role of neural pools in the CNS?

To process information

Looking up a new phone number and then dialing it from memory utilizes which type of memory?

Working memory

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

dendrites

Which best describes signal conduction in unmyelinated axons?

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

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

Peripheral nervous system

Match each glial cell type with its location and function. Satellite Cells- Schwann Cells- Ependymal Cells- Microglia-

Satellite Cells-In the PNS; surround somas of neurons in ganglia, provide electrical insulation, and regulate the chemical environment of neurons Schwann Cells-In the PNS; form neurilemma around all PNS fibers and myelin around most of them; aid in regeneration of damaged nerve fibers. Ependymal Cells-In the CNS; line cavities of the brain and spinal cord; secrete and circulate CSF Microglia-In the CNS; phagocytize microorganisms, foreign matter, and dead nervous tissue

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

True

Select all that apply Indicate which of the following statements are true about signal conduction along unmyelinated fibers.

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

How long can long-term memory last?

Up to a lifetime

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

Visceral motor

Which best describes an electrical potential?

a form of potential energy that can produce current

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

absolute

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

endocrine, nervous

A cholinergic synapse uses which of the following as its neurotransmitter?

Acetylcholine

Select all that apply How do neuromodulators alter synaptic transmission?

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

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

Central and peripheral nervous systems

Select all that apply Select the four categories of neurotransmitters based on chemical composition.

Monoamines Amino acids Acetylcholine Neuropeptides

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

Neural integration

Immediate memory, which is the ability to hold something in mind for a few seconds, might be based on activity in which type of neural circuit?

Reverberating