McGraw Hill Connect Assignments

Which best describes signal conduction in unmyelinated axons ?

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

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

Acetylcholine

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

Choose all the ways 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

Select all that are categories of neurotransmitters based on chemical composition .

Amino acids . Acetylcholine Neuropeptides Monoamines

The spinoreticular tract is part of the system in anterior and lateral columns.

Anterolateral

Nerve tract is indicated by the black arrow in the arrow figure?

Anterolateral System

Meninx is just below (Deep to) the dura mater

Arachnoid Mater

What is the white matter of the spinal cord

Bundles of myelinated and unmyelinated axons found superficial to the gray matter

In the spinal cord what is the space within the gray commissure that contains CFS?

Central Canal

Choose all that would cause postsynaptic stimulation to end .

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

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

Cholinergic

In the spinoreticular tract, the second order neurons decussate to where?

Contralateral anterolateral system

The nerve fibers of the tract from ridges called pyramids on the anterior surface of the medulla

Corticospinal

The tract that Carries signals for precise, finely coordinated limb movements is the tract

Corticospinal

Tract located in picture

Cuneate fasciculus

Choose all that are characteristics of local potentials .

Decremental & Graded

Because the nerve track of the spinal cord undergo the right side of the brain communicates with the last side of the brain and vice versa

Decussation

Choose all the factors that influence the speed of nerve signal conduction .

Diameter of axon Presence of myelin .

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

False

Where is the origin of sensory signals carried by the cuneate fascicules?

From vertebra T6 and up

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

Gap junctions .

The fibers of the gracile fasciculus terminate at the ____ nucleus of the medulla oblongata.

Gracile

In a synapse , where are synaptic vesicles located ?

In the axon terminal

Which term refers to decremental changes in electrical potential along

Local potentials

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

More neurotransmitter will be released

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

Neurotransmitter removed from postsynaptic receptors .

The spinoreticular tract carriers what type of signals?

Pain

The third-order neurons of spinoreticular tract runs from the____to the thalamus

Pons

Which term refers to the period of time after a nerve cell has responded to a stimulus excited by a threshold stimulus ?

Refractory period

Choose all that are properties of action potentials .

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

Two tracts indicated in the black arrow

Spinothalamic tract Spinoreticular tract

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

Synaptic cleft

Choose all the statements that characterize neurotransmitters ?

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

In a sensory pathway which neurons run from the thalamus to the sensory cerebral cortex?

Third in order

How many neurons are typically found in an ascending pathway between the receptors and the brain?

Three

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

True

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 . A zone of depolarization excites voltage - gated channels immediately distal to the action potential .

What is the source of the sensory signals carried by the cuneate fasciculus ?

Upper limbs and chest

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

absolute

The spinoreticular tract is found in which columns of the spinal cord?

anterior and lateral

The spinothalamic tract is found in which columns of the spinal cord?

anterior and lateral

The spinothalamic tract is part of which system in the anterior and lateral columns ?

anterolateral system

Which meninx consists of several layers of squamous epithelial cells with a mesh of fibers in the adjoining space?

arachnoid mater

Within the spinal cord, which tracts carry information up to the brain?

ascending

cuneate fasciculus

carries sensations of movement, deep touch, visceral pain and vibration above T6

What does the central canal of the spinal cord contain?

cerebrospinal fluid

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

cholinergic

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

functions of spinal cord

conduction, locomotion, reflexes

Since the corticospinal tracts decussate, innervation to the muscles will be across the body or

contralateral

Since the corticospinal tracts decussate, they will innervate which muscles?

contralateral

Which tract will have its origin and destination of opposite sides of the body?

contralateral

Which tract carries signals for precise, finely coordinated limb movements?

corticospinal

Which tract is also called a pyramidal tract?

corticospinal

What factor accounts for the fact that the right side of the brain communicates with the left side of the body, and vice versa?

decussation

The dural sheath around the spinal cord is formed from the ____ mater.

dura mater

What is the order of the meninges from superficial to deep?

dura mater, arachnoid mater, pia mater

meninges in order from superficial to deep

dura mater, arachnoid mater, pia mater

Which order neuron of the spinothalamic tract ends in the posterior horn at the point of entry to the spinal cord?

first

Which order neurons of the spinocerebellar tract originate at muscles and tendons?

first

What structure marks the superior end of the spinal cord?

foramen magnum

Nerve signals carried from the midthoracic and lower parts of the body are carried by which ascending tract?

gracile fasciculus

Which tract is fasciculus?

gracile fasciculus

Where do the nerve fibers of the gracile fasciculus terminate in the medulla oblongata?

gracile nucleus

Which nerve tracts do not decussate

ipsilateral

In which column of the spinal cord is the anterior spinocerebellar tract found?

lateral

In descending tracts, which motor neuron innervates the target organ?

lower

Which motor neurons (which are the motor neurons connecting the brainstem and spinal cord muscle fibers) of the descending pathway innervate skeletal muscle?

lower

The poliovirus destroys which neurons in the brainstem and anterior horn of the spinal cord?

motor

Within the spinal cord what type of information do the descending tracts carry?

motor

Where do the first-order neurons of the spinocerebellar tract originate?

muscles and tendons

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

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

What does contralateral mean?

on the opposite side of the body

The cuneate fasciculus is located in which fasciculus of the spinal cord?

posterior

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 or Postsynaptic

An electrical potential is a form what type of energy ?

potential energy

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

presynaptic

Role of Neural Pools in the CNS?

process information

What type of signal does the spinocerebellar tract carry?

proprioception

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

relative

The second-order neurons of the spinoreticular tract terminate in the formation of the brainstem.

reticular

In the spinothalamic tract the which order neurons decussate from the posterior horn of the spinal cord?

second

In a sensory pathway Which neurons run from the spinal cord or brainstem to the thalamus?

second order

Which pathways are made up of three neurons?

sensory

Signals for proprioception are carried by the anterior and posterior ____ tract.

spinocerebellar

Where do the third-order neurons of the spinoreticular tract run from the pons to?

thalamus

How many neurons are found in a descending tract?

two

Consider the two motor neurons that form descending pathways. The neurons called _______ motor neurons have their somas in the cerebral cortex or brainstem

upper

In descending pathways, which motor neurons have their somas in the cerebral cortex or brainstem?

upper

The matter that is composed of myelinated and unmyelinated axons and is superficial to the gray matter of the spinal cord is called?

white matter