Unit 4 exam
The superficial covering over the entire nerve is called:
Epineurium
Which of the following is not true for spinal nerves?
Every pair of spinal nerves exits through the intervertebral foramina above the vertebra that has the same name and number as the nerves.
If a neurotransmitter depolarizes the postsynaptic membrane it is referred to as:
Excitatory
A nerve is a single neuron that transmits a nerve impulse.
False
All regions of the spinal cord contain lateral, dorsal, and ventral gray horns.
False
An EPSP is when the sodium channels open and sodium diffuses in hyperpolarizing the membrane.
False
An IPSP is when the sodium channels open and sodium diffuses in hyperpolarizing the membrane.
False
Astrocytes form the myelin sheaths within the central nervous system.
False
Bipolar neurons have only one nerve fiber which leaves the cell body and branches into two separate fibers - the axon and the dendrite.
False
Complete paralysis of the diaphragm occurs if the spinal cord is severed just below the fifth cervical nerve.
False
Which is not a type of channel used in production of an electrical signal in neurons?
Ion dependent channel
When a nerve fiber is at its resting potential (polarized), the concentration of ___
Na+ ions is higher on the outside of its membrane and K+ ions is higher on the inside.
True
Neurons are cells in the nervous system that transmits a nerve impulse.
fine processes at the ends of axons
Select the best description of axon terminals:
usually myelinated
Select the best description of axon:
form(s) part of the cytoskeleton
Select the best description of neurofibrils:
Which of the following is not a function of the nervous system?
Sensory function Integrative function Motor function
Which of the following parts of a reflex arc would have a cell body in the dorsal root (ganglion)s?
Sensory neuron
Which of the following parts of a reflex arc monitors body conditions?
Sensory receptor
These white matter tracts of the spinal cord contain ascending information:
Sensory tracts
The peripheral nervous system can be divided into:
Somatic nervous system Autonomic nervous system Enteric nervous system
Which of the below contains cerebrospinal fluid?
Subarachnoid space
Dendrites conduct signals toward the neuron cell body; the axon conducts nerve impulses away from the neuron cell body.
True
Hyperpolarization is the membrane potential moving away from zero in a more negative direction.
True
Interneurons are links between multipolar neurons in the central nervous system
True
Lateral extensions of the pia mater, called denticulate ligaments, suspend the spinal cord in the middle of the dural sheath, providing protection against shock and sudden displacement.
True
Most brain tumors are formed from neuroglial cells.
True
Motor neurons carry impulses from the brain or spinal cord to the periphery.
True
Motor neurons that supply smooth muscle, cardiac muscle, or glands via the autonomic nervous system can be found in the lateral gray horns of the spinal cord.
True
Neurons are cells in the nervous system that transmits a nerve impulse.
True
Neurons that originate in the central nervous system and that function to carry information to smooth, skeletal, or cardiac muscle are efferent neurons.
True
New fibers can form along the degenerating neurilemma in the peripheral nervous system allowing for some tissue regeneration.
True
Sensory information is transmitted to the cell body along dendrites.
True
Sensory information is transmitted to the neuron cell body along dendrites.
True
The afferent portion of the autonomic nervous system carries sensory information from the viscera to the central nervous system.
True
The afferent portion of the somatic nervous system carries sensory information from the eyes and ears to the central nervous system.
True
The denticulate ligaments and the filum terminale are both structures that help to anchor the spinal cord and protect it against sudden displacement.
True
The dorsal root ganglion contains the cell bodies of sensory neurons.
True
The efferent portion of the autonomic nervous system consists of sympathetic and parasympathetic divisions.
True
The epidural space found between the dura mater and the wall of the vertebral canal contains a protective cushion of fat and connective tissue.
True
The nodes of Ranvier are the non-myelinated portions of the axon.
True
The portion of the plasma membrane of a neuron that surrounds the axoplasm is called the axolemma.
True
The refractory period requires ATP to complete the movement of ions.
True
The refractory period requires calcium to complete the movement of ions.
True
The thin transparent spinal meninx called pia mater separates the spinal cord from the surrounding cerebrospinal fluid.
True
The vast majority of neurons in the body are interneurons.
True
There are two types of neuroglia that produce myelin sheaths: oligodendrocytes and Schwann cells.
True
Unipolar neurons are always sensory neurons.
True
___ is the major neurotransmitter of the parasympathetic division of the autonomic nervous system.
acetylcholine
The meninges are layers of connective tissue that:
surround the brain and spinal cord. cover the spinal nerves up to where they exit through the intervertebral foramina. are called, in order from external to internal: dura mater, arachnoid mater, and pia mater.
Select the best description of the satellite cells:
surround neurons in peripheral nervous system ganglia
White matter includes:
tracts in the spinal cord.
Sensory neurons carry information from the periphery to the brain or spinal cord.
true
A synapse is a junction between:
two neurons. a neuron and a muscle cell. a neuron and a glandular cell.
Select the best description of dendrites:
usually short and branched
The cell bodies of motor neurons are located in the ___
ventral horn of gray matter.
Interneurons are links between multipolar neurons in the peripheral nervous system.
False
Most brain tumors are formed from neurons.
False
Motor information is transmitted to the cell body along dendrites.
False
Nerves are cells in the nervous system that transmits a nerve impulse.
False
Neurofibrils are membranous sacs spread throughout the cytoplasm of a neuron.
False
New fibers can form along the degenerating neurilemma in the central nervous system allowing for some tissue regeneration.
False
Sensory information is transmitted to the neuron cell body along the axon.
False
Sensory neurons carry impulses from the brain to the periphery.
False
The choroid plexus is the fluid produced in the lateral ventricle.
False
The dorsal root ganglion contains the cell bodies of motor neurons.
False
The femoral nerve is a branch of the sciatic nerve.
False
The name given to rough endoplasmic reticulum in neurons is lipofuscin granules.
False
The neuroglia cells that are derived from monocytes are called astrocytes.
False
The nodes of Ranvier are the myelin covered portions of the axon.
False
The central canal of the spinal cord is located in the:
gray commissure.
When compared to unmyelinated axons, myelinated axons: 1) are electrically insulated, 2) are gray in color, 3) have a faster speed of nerve impulse conduction, 4) are more numerous
1, 3, 4
The roots of which spinal nerves make up the cauda equina? 1) Thoracic, 2) Lumbar, 3) Sacral, and 4) Coccygeal
2, 3, 4
This pathway governs automatic movements and coordinates them with visual stimuli.
Indirect pathway
A typical reflex arc involves the following components: 1) sensory neuron, 2) motor neuron, 3) receptor, 4) one or more interneurons, and 5) effector. The correct order is:
3, 1, 4, 2, 5
The resting membrane potential in neurons ranges from:
40 to -90 mV
IPSP stands for:
Inhibitory postsynaptic potential
Which of the following terms describes synapses?
All of the above
Spinal nerves
Are part of the PNS Connect the CNS to the body Are named according to the region of the cord from which they emerge
Where does summation occur?
At the trigger zone
This type of neuron has one main dendrite and one main axon.
Bipolar neuron
Nerve fiber refers to:
Both axon and dendrites
Which type of axons contain endoneurium?
Both myelinated and unmyelinated
The motor portion of the autonomic nervous system can be divided into:
Both sympathetic and parasympathetic divisions
Which of the following ions is responsible for the exocytosis of the neurotransmitters housed in the synaptic vesicles?
Ca+2
A polarized cell
Can vary from +5 to -100 mV Includes most cells of the body Exhibits a membrane potential
Plasticity means
Capability to change based on experience
In response to a muscle being overstretched, a muscle spindle generates a somatic spinal reflex that, ultimately, causes what response?
Contraction of the agonist muscle Relaxation of the antagonist muscle
An ipsilateral and intersegmental spinal somatic reflex
Controls many flexor and extensor muscles on one side of the body
This pathway conveys nerve impulses that originate in the cerebral cortex and are destined to cause precise, voluntary movements of skeletal muscles.
Direct pathway
This neural circuit consists of a single presynaptic neuron synapsing with several postsynaptic neurons.
Diverging circuit
This serves the deep muscles and skin of the dorsal surface of the trunk.
Dorsal ramus
In response to being stretched a muscle spindle generates nerve impulses that propagate along a sensory neuron through which below structure, to get into the spinal column?
Dorsal root
This contains only sensory axons that conduct nerve impulses from sensory receptors in the skin, muscles and internal organs into the CNS.
Dorsal root
Which of the three spinal meninges is the most superficial?
Dura mater
A postsynaptic neuron may respond to inhibitory and excitatory effects in which of the following ways:
EPSP Nerve impulse IPSP
What phenomenon explains why a light touch feels different than a touch applied with more pressure?
Frequency of impulses
lumbar
From which plexus does the femoral nerve arise?
Which of the following neurotransmitters functions to inhibit central nervous system functions?
GABA
This contains neuronal cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglia.
Gray matter
This is a structure that results from nervous input from the lower extremities.
Lumbar enlargement
A depolarizing graded potential
Makes the membrane less polarized, moving toward zero
The descending tracts of the spinal cord carry what type of information:
Motor
Which of the following parts of a reflex arc monitors body conditions?
Motor neuron
False
Motor neurons carry impulses from the periphery to the brain or spinal cord.
Membranous sacs found throughout the cytoplasm of neurons that consists of rough endoplasmic reticulum are called ___
Nissl bodies.
A reflex pathway having only one synapse in the CNS is called
None of the above
Saltatory conduction
None of the above
Denticulate ligaments are thickenings of the ___ .
Pia mater
During a somatic spinal reflex, when one effector muscle is stimulated and the opposing muscle is inhibited, this type of innervation is called
Reciprocal
In response to excessive tension on a tendon, a tendon organ generates a somatic spinal reflex that, ultimately, causes what response?
Relaxation of the agonist muscle Contraction of the antagonist muscle
Diffusion, enzymatic degradation, and uptake by cells are all ways to
Remove a neurotransmitter
False
The ventral median fissure of the spinal cord is shallower and narrower than the dorsal median sulcus.
Dopamine
This neurotransmitter inhibits motor functions at the basal ganglia.
A nerve is a group of fibers in the nervous system that transmits impulses.
True
A neurolemma is a characteristic of cells located in the peripheral nervous system, but not in the central nervous system.
True
A significant difference between neurons and neuroglia is that mature neuroglia can divide; mature neurons cannot.
True
An EPSP is when the potassium channels open and potassium diffuses out hypopolarizing the membrane.
True
An IPSP is when the potassium channels open and potassium diffuses out hypopolarizing the membrane.
True
___ enhances the receptor binding of GABA decreasing anxiety.
Valium
When a depolarizing graded potential makes the membrane depolarize to threshold
Voltage gated Na+ channels open rapidly
This tract carries nerve impulses for proprioception.
White columns
Accidentally stepping on a nail with the sole of your foot causes you quite a bit of discomfort. Which type of pathway is involved in relaying information about the nail?
afferent
The peripheral nervous system carries _____ (or sensory) impulses from the _____ to the _____.
afferent, receptors, central nervous system
The peripheral nervous system consists of:
all of the above.
Which neuroglia would be most responsible for helping to prevent pathogens and toxins from entering the brain from the blood?
astrocytes
This has the property of electrical excitability.
both muscle cells and neurons
From which plexus does the axillary nerve arise?
brachial
From which plexus does the ulnar nerve arise?
brachial
When an action potential passes over the surface of a synaptic knob, the contents of the vesicles are released in response to the presence of ___
calcium ions.
If the body had a low calcium level, then this could affect the release of neurotransmitters by ___
causing a decrease in the amount released from synaptic knobs.
The arachnoid mater lies between two fluids: interstitial fluid on its outer surface and _____ fluid on its inner surface.
cerebrospinal
From which plexus does the phrenic nerve arise?
cervical
The main plexuses formed by the ventral rami of spinal nerves are:
cervical, brachial, lumbar, and sacral.
What is the best description of the arachnoid mater?
consists of collagen and elastic fiber network; has no blood vessels
What is the best description of the epidural space?
contains a layer of adipose tissue
The simplest reflex arc is a pathway that:
contains only one neuron. consists of a sensory neuron, an interneuron, and a motor neuron. consists of a sensory neuron and an interneuron.
Select the area innervated by the axillary nerve.
deltoid muscle
The nerve fiber that provides the main receptive surfaces (incoming impulse) for neurons are ___
dendrites.
A cell membrane moving toward zero to a more positive state is called ___
depolarization.
If a resting potential becomes less negative, the membrane is said to be ___
depolarizing
Select the area innervated by the phrenic nerve.
diaphragm
This neurotransmitter inhibits motor functions at the basal ganglia.
dopamine
Cell bodies of sensory neurons are found where within the nervous system?
dorsal root ganglion
The cell bodies of sensory neurons are located in the ___
dorsal root ganglion.
Which of the following parts of a reflex arc changes body condition levels?
effector
In order to flex your fingers, what type of impulse will the flexor digitorum superficialis muscle need to receive?
efferent
Which layer is found surrounding the entire spinal nerve?
epineurium
Select the area innervated by the radial nerve.
extensors of the wrist
A nerve is a cell in the nervous system that transmits an impulse.
false
A nerve is a single neuron that transmits a nerve impulse.
false
Gray matter is located only in the brain.
false
The inferior extension of the pia mater that anchors the spinal cord to the coccyx is called the _____.
filum terminale
Select the area innervated by the median nerve.
flexors of the wrist
Select the best description of the ependymal cells:
form lining of brain ventricles
Select the best description of the oligodendrocytes:
form myelin sheaths in central nervous system
Select the best description of the Schwann cells:
form myelin sheaths of peripheral nervous system
Select the area innervated by the tibial nerve.
gastrocnemius and soleus muscles
This neurotransmitter inhibits spinal cord functions.
glycine
Select the best description of astrocytes:
help maintain the blood-brain barrier
The cell has the following conditions during the resting potential
high Na+ outside with high K+ inside waiting for the Na+ channels to open
A cell membrane moving away from zero to a more negative state is called ___
hyperpolarization.
As the membrane potential becomes more negative (moving from -70 mV to -90 mV), the membrane is ___
hyperpolarizing
Motor impulses that help maintain muscle tone and posture are conveyed from the brain through the spinal cord by the:
indirect pathways.
An IPSP is an ___ where ___ channels open ___ the membrane.
inhibitory postsynaptic potential; K+; hyperpolarizing
Another term for the thoracic nerves is
intercostals
The gray matter of the spinal cord:
is subdivided into regions called horns. is surrounded by white matter. contains
From which plexus does the femoral nerve arise?
lumbar
A main difference between neurons and neuroglia is:
mature neurons do not normally divide; neuroglia do.
Select the best description of nerve fiber:
may refer to either axons or dendrites
What is the best description of the dura mater?
meninx closest to the bone of the vertebral column
___ blocks enzymatic degradation of norepinephrine in the presynaptic cell elevating mood.
monoamine oxidase inhibitors
Dendrites are processes of a neuron that:
none of the above
The simplest reflex arc is a pathway that:
none of the above.
The action potential repolarizes the membrane by ___
opening K+ channels which causes K+ to flood out of the cell.
The action potential depolarizes the membrane by ___
opening Na+ channels which causes Na+ to flood into the cell.
At a synapse between the axon of one cell and the dendrite of another cell, the axon would always be part of the _____ neuron; the dendrite would always be part of the _____ neuron.
presynaptic, postsynaptic
Select the area innervated by the femoral nerve.
quadriceps femoris muscle
Which of the following lists the parts of a reflex arc in the correct sequence?
receptor, sensory neuron, interneuron, motor neuron, effector
___ is the stage of an action potential where sodium is being pumped out and potassium is being pumped in by active transport restoring the membrane potential.
refractory period
Which of the following is not found in neurons?
sarcoplasmic reticulum
This neurotransmitter is believed to be involved in inducing sleep within central nervous system.
serotonin
A pathway called a reflex arc terminates at an effector, which could be:
skeletal muscle. smooth or cardiac muscle. gland.
When a nerve fiber has been depolarized, the concentration of ___
sodium and potassium ions are higher on the inside of membrane.
A motor unit in skeletal muscle is activated by a/an _____.
somatic motor neuron
The peripheral nervous system consists of:
somatic nervous system and autonomic nervous system. sensory neurons and motor neurons. cranial nerves and spinal nerves.
Select the best description of neurotransmitter molecules:
stored in synaptic vesicles
Which structure of the neuron will contain the greatest number of neurotransmitter receptors?
the dendrites
Lack of sensation in the umbilical region is most likely the result of an injury to:
the dorsal root of T10
The conus medullaris is:
the tapering end of the spinal cord inferior to the lumbar enlargement.
Spinal nerves T2-T12 differ from all other spinal nerves in that:
the ventral rami do not contribute to a plexus.
Regeneration of nerve fibers in the central nervous system is highly unlikely because:
there are no neurolemmas. oligodendrocytes inhibit axon regeneration. astrocytes rapidly form a physical barrier of scar tissue.
Motor information is transmitted to the cell body along dendrites.
they synthesize neurotransmitters.
Which of the following pairs of terms is most closely matched?
white matter, tracts in the central nervous system
