Exam 4 #2 Flashcards
If you experimentally increase the permeability of an axonal membrane to sodium ions, the resting membrane potential for the neuron will
Increase because the influx of sodium depolarizes the neuron
decrease because the influx of sodium depolarizes the neuron
decrease because the efflux of potassium that follows sodium influx repolarizes the membrane
remain unchanged
Increase because the influx of sodium depolarizes the neuron
Neurotransmitters are stored in the
sarcoplasmic reticulum
intercalated disc
synaptic vesicles
neurotransmitters are not stored but they are free floating in the extracellular space
neurotransmitters are not stored but they are free floating in the extracellular space
Which of the following neurons forms the blood-brain barrier?
astrocyte microglial cell oligodendrocytes ependymal cell none of the above
None of the above
The Nat-K* ATPase pump
pumps three sodium inside the cell and two potassium ions outside
pumps two sodium ions outside the cell and three potassium ions inside
pumps an equal ration of sodium and potassium against its concentration gradient
pumps three sodium ions to the outside the cell and two potassium ions to the inside
pumps three sodium ions to the outside the cell and two potassium ions to the inside
During depolarization
sodium ions move rapidly out of the cell
potassium ions move rapidly out of the cell
sodium ions move rapidly into the cell
potassium ions move rapidly into the cell
sodium ions move rapidly into the cell
Decreasing the diameter of an'axon will results in a decrease in the conduction velocity an increase in the conduction velocity no change in the conduction velocity none of the above
a decrease in the conduction velocity
A resting membrane potential is -70 mV and the threshold is determined to be -60 mV. A change in membrane potential to -52 mV will results in
depolarization
hyperpolarization
an action potential
repolarization
An action potential
Endocytosis of neurotransmitters into the synaptic cleft is dependent upon
Ca2+ efflux
Ca2t influx
Active transport of Ca2+ into the cell
None of the above
None of the above
The absolute refractory period is defined as
a point where Nat channels begin to inactivate and the K+ channels are still activatine
the point where the Nat current is equal and opposite the K+ current
the point where an action potential cannot be evoked, regardless of the stimulus strength
the point where an action potential can only be evoked by a stronger then normal stimulus
the point where an action potential cannot be evoked, regardless of the stimulus strength
A neural tissue has a resting membrane potential of -75 mV. Closing the K+ voltage gated channels will most likely result in
depolarization repolarization hyperpolarization initiation of an action potential no change in membrane potential
Depolarization
Inhibitory postsynaptic potentials (IPSPs)
result in local depolarization result in local hyperpolarization result in local repolarization increase membrane permeability to sodium ions prevent the efflux of calcium ions
Result in local hyperpolarization
The resting membrane potential of a cardiac cell is -70 mV. An influx of [Ca2*] will
make the cell more excitable
make the cell less excitable
no effect on resting membrane potential
calcium cannot influx, it can only efflux
Make the cell more excitable
Neurotransmitters are released into the synaptic cleft and bind to
presynaptic terminal
the synaptic knob receptors
calcium ions
receptors on the postsynaptic membrane
receptors on the postsynaptic membrane
A slight shift away from the resting membrane potential is termed
membrane potential
resting membrane potential
local or graded potential
action potential
Local or graded potential
When an action potential reaches the axonal bulb
the pre and postsynaptic neurons come in direct contact
the nerve impulse will pass in either direction
an electrical spark will jump the gap
chemical transmitters are released
chemical transmitters are released
Which of the following fiber types would one expect to have the greatest rate of impulse conduction?
type A fiber
type B fiber
type C fiber
type D fiber
Type A fiber
At resting membrane potential, which of the following ions leak “freely” through the membrane channels?
N+
K+
Ca?t
CI
K+
Which of the following neurotransmitters is inhibitory in function?
Acetylcholine Substance P Norepinephrine Glycine All of the above neurotransmitters are excitatory in action
Glycine
An increase in extracellular (Ca2*] will result in
depolarization
repolarization
hyperpolarization
no physiological effect on resting membrane potential
no physiological effect on resting membrane potential
An inhibitory neurotransmitter is released into the synaptic cleft. Which of the following channels will most likely be stimulated to open? Sodium and potassium channels Potassium and/or chioride channels Sodium and chloride channels Only the sodium channels
Potassium and/or chloride channels
The resting membrane potential for a typical cardiac cell is -60 mV. Changing the resting membrane potertial to -70 mV will result in
depolarization
repolarization
hyperpolarization
no effect on resting membrane potential since calcium is the primary ion for the initiation of an action potential for a typical contracting cardiomyopathy
Hyperpolarization
The resting membrane potential for a sensory neuron is -80 mV. Increasing the extracellular [Nat] will result in
a local potential
an increase in the amplitude of the action potential spike
a decrease in the amplitude of the action potential spike
hyperpolarization
repolarization
an increase in the amplitude of the action potential spike
The resting membrane potential for a motor neuron axon is -90 mV. An influx of chloride ions (CI) will catse the resting
membrane potential to
become more excitable
become less excitable
remain at -90 mV
depolarize
Become less excitable
Transmission of nerve impulses across a synaptic cleft is mediated by
sodium ions
potassium ions
neurotransmitters
the node of Ranvier
neurotransmitters
All the following statements are correct for myelin sheath EXCEPT
It is associated with white fibers (matter) in the brain
It is important in nerve conduction velocity
It covers cell bodies in the brain and spinal cord
It is destroyed in multiple sclerosis
It covers cell bodies in the brain and spinal cord
The resting membrane potential for a motor neuron is -90 mV. Decreasing the extracellular [K*] will cause the neuron to become
more excitable
less excitable
repolarize
no change in the resting membrane potential
Less excitable
A neuron is said to be polarized because
the action potential can travel in a bilateral direction
the soma is always at one extremity of the cell
there is a difference of electrical potential across its membrane
it tends to cluster with other neurons in nuclei.
there is a difference of electrical potential across its membrane
All the following statements regarding acetylcholine and the activities occurring at the cholinergic synapse are correct EXCEPT
calcium ions influx into an axonal terminal stimulates the release of ACh from vesicles
ACh is stimulatory to skeletal muscle causing depolarization
ACh is inhibitory in cardiac muscle causing hyperpolarization
Excess ACh is removed by acetylcholineesterase in the synaptic cleft
ACh moves from the post synaptic neuron to the presynaptic neuron
ACh moves from the post synaptic neuron to the presynaptic neuron
The resistance across the cell membrane is determined by
the thickness of the membrane the amount of lipid in the membrane the surface area of the membrane the number of type of channels In the membrane the axoplasmic flow
the number of type of channels In the membrane
The primary determinant of the resting membrane potential is
the membrane permeability and influx of sodium
the membrane permeability and influx of potassium
the negative charge of the interstitial fluid
the positively charged cellular cytoplasm
none of the above
None of the above
An increased in extracellular [K*] will cause the neuron to
depolarize
repolarize
hyperpolarize
none of the above
Depolarize
The relative refractory period is defined as
a point where Na* channels begin to inactivate and the K* channels are still activating
the point where the Na* current is equal and opposite the K* current
the point where an action potential cannot be evoked, regardless of the stimulus strength
the point where an action potential can only be evoked by a stronger the normal stimulus
the point where an action potential can only be evoked by a stronger the normal stimulus
Excitatory postsynaptic potentials (EPSPs)
result in local depolarization
result in local hyperpolarization
result in local repolarization
increase membrane permeability to potassium ions
decreased membrane permeability to calcium ions
result in local depolarization
The ulna nerve is covered by the: endoneurium perineurium epineurium macroneurum
epineurium
An inhibitory neurotransmitter is released into the synaptic cleft. Which of the following channels will most likely be stimulated to open?
Sodium and potassium channels
Potassium and/or chloride channels
Sodium and chloride channels
Oniv the sodium channels
Potassium and/or chloride channels
The cellular loss of positive ions such as potassium from a resting neuron causes
the neuron to become less negative
depolarization
Hyperpolarization
The cellular loss of positive ions such as potassium from a resting neuron causes
The threshold to be reached with a resulting action potential
Only A& C
Hyperpolarization
If a neurotransmitter binds to receptor molecules that open K* ion channels, the result is
an excitatory postsynaptic potential an inhibitory postsynaptic potential Local depolarization increased permeability of presynaptic membrane to Ca?+ ions temporal summation
an inhibitory postsynaptic potential
The difference between sodium and potassium in the generation of action potential is:
Sodium causes repolarization while potassium causes depolarization
Sodium causes unipolarization while potassium causes repolarization
Sodium causes repolarization while potassium is not required in the action potential mechanism
Sodium causes depolarization while potassium causes repolarization
None of the above
Sodium causes depolarization while potassium causes repolarization
Which of the following statements is most correct for saltatory conduction?
The action potentials move in all directions along an axon
The action potentials occur at successive nodes along the length of the stimulated axon
The local currents depolarize adjacent areas of membrane so that action potentials continue to form along the membrane
All the above
None of the above
The action potentials occur at successive nodes along the length of the stimulated axon
Lesions on a bundle of myelinated fibers will most likely result in
Nerve conduction would be enhanced with an increase in motor coordination
There would be no side effects of this type of lesion
Nerve conduction would be impaired and weakness, loss of coordination, and visual impairment would occur
Nerve conduction would be impaired but complete regeneration will ensue
None of the above
Nerve conduction would be impaired and weakness, loss of coordination, and visual impairment would occur
A 65-year-old recently diagnosed with cerebral vascular accident, i.e., stroke. As a direct result from the stroke, some of the neural tissues were
damaged. What type of neuroglia would you expect to find at the site of injury and is involved in scar formation?
Astrocytes Satellite cells Ependymal cells Microgila Oligodendrocytes
Astrocytes
Which of the following groove is found between the frontal and parietal lobes?
Central sulcus of Rolando
Lateral suícus of Sylvius
Transverse fissure
Sagittal sinus of Galen
Central sulcus of Rolando
The central sulcus separates the \_\_\_ from the \_\_\_\_ lobe Temporal/occipital Frontal/parietal Parietal/occipital Temporal/frontal Frontal/occipital
Frontal/parietal
The ability to think and solve problems resides in which area of the cerebrum?
Frontal Parietal Occipital Temporal Insula
Frontal
The primary somatosensory cortex is located in the
Frontal lobe Precentral gyrus Parietal lobe Occipital lobe Temporal lobe
Parietal lobe
The cerebellum functions in
The planning and coordination of movement
Learning, memory, and personality
Biological rhythms
Homeostatic functions such as breathing and heart rate
None of the above
The planning and coordination of movement
Bundles of white matter in the cerebrum are known as
Arbor vitae Ganglia Tracts Nuclei Myelinated axons
Tracts
What are the three primary brain vesicles that form from the neural tube?
Mesencephalon, telencephalon, diencephalon
Forebrain, midbrain, hindbrain
Telencephalon, myelencephalon, mesencephalon
Cerebrum, thalamus, cerebellum
Midbrain, pons, medulla
Forebrain, midbrain, hindbrain
The primary motor cortex of the right hemisphere
Controls the motor activity on the left side of the body
Receives and processes sensory input
Integrates senses from multiple different sources
Controls motor activity on the right side of the body
Involved in proprioception
Controls the motor activity on the left side of the body
What is the most likely result when the corpus callosum is transected?
communication between a cerebral cortex in one hemisphere with other areas of the same hemisphere would be impaired
communication between the brain and spinal cord would be impaired
communication within a single brain hemisphere would be impaired communication between the right and left cerebral hemispheres would be impaired
none of the above
communication between the right and left cerebral hemispheres would be impaired
Cerebrospinal fluid (SF) in the third ventricle will drain/flow into the
Lateral ventricles Fourth ventricles Choroid plexus Dural sinua Subarachnoid space
Fourth ventricles
Which of the following structures carries information from the brain? Posterior column Dorsal column medial lemniscus Spinocerebellar tract Anterolateral system Corticospinal tract
Corticospinal tract
Where is the sensation of touch processed?
Prefrontal cortex Primary motor cortex Primary somatosensory cortex Somatosensory association area/cortex Cerebellum
Primary somatosensory cortex
What part of the cerebral cortex is responsible for personality, the creation of an awareness of self, and the ability to recognize appropriate behavior?
Parietal association area Wernicke's area Prefrontal cortex Basal nuclei None of the above
Prefrontal cortex
Visual stimuli that arrive in the thalamus are relayed to the
Primary visual cortex in the frontal lobe
Primary visual cortex in the occipital lobe
Medulla
Brainstem nuciel
Reticular systen
Primary visual cortex in the occipital lobe
The pineal gland, and endocrine structure that secretes the hormone melatonin, is found in the
Cerebrum Diencephalon Midbrain Brain stem Hindbrain
Diencephalon
The right and left cerebral hemispheres are connected by Association fibers Commissural fibers Projection fibers Directional fibers All the above
Commissural fibers
Which of the following statements is most correct?
Tracts are unmyelinated axons located in the PNS
swered
White matter of the brain is located peripherally
Nuclei are collection of nerve cell bodies
Ganglion are collection of myelinated axons
Arbor vitae represent gray matter in the cerebellum
Nuclei are collection of nerve cell bodies
The ______ contains centers for heartbeat, breathing, and blood pressure.
cerebellum cerebrum spinal cord rect! brain stem
brain stem
are axons which connect the corresponding gray areas of the two brain hemispheres. Most pass through (and form) the \_\_\_\_ Projection fibers, corpus callosum Commissural fibers, corpus callosum Association fibers, basal nuclei Basal fibers, basal ganglia Substantia nigra, Broca's area
Commissural fibers, corpus callosum
Collectively and functionally, the ____ are called the brain stem.
midbrain, pons medulla cerebellum onlv A. B. & C
Only A. B. C
Nerve fibers carrying signals from the CNS to the PNS are called.\_\_\_ or \_\_\_ fibers Afferent, sensory Afferent, motor Motor, efferent Efferent, afferent All of the above
Motor, efferent
The brain and spinal cord make up the ____ nervous system. All other nerves are part of the _____ nervous system.
Central, peripheral Peripheral, central Autonomic, somatic Somatic, autonomic Sympathetic, parasympathetic
Central, peripheral
In the CNS, ____ are cells which line the fluid-filled cavities, and which secrete, transport, and circulate the fluid surrounding the brain and spinal CNS
Astrocytes Microglias, Ependymal Oligodendrocytes Schwann cells
Ependymal
The rough endoplasmic reticulum in neurons are called Organelles Nissl bodies Golgi bodies Cajal bodies neurotransmitters
Nissl bodies
is a collection of neuronal cell bodies located inside of the CNS.
Nucleus Ganglion Nerve Tract None of the above
Nucleus
A \_\_\_\_\_\_ is a collection of neuronal axons, blood vessels, and connective tissues in the PNS. Nucleus Ganglion Nerve Tract None of the above
Nerve
The folds and convolutions of the, cerebral hemispheres are namèd for their three-dimensional form. The ridges are called
Gyri Sulci Fissures Ventricles ) Mater
Gyri
The folds and convolutions of the cerebral hemispheres are named for their three-dimensional form. The shallow grooves are called
Gyri Fissures Mater Sulci Ventricles
Sulci
The resting membrane potential arises because
a fast Na+ channel opens transiently, allowing Na+ to flow down its osmotic gradient
the chemical gradient is equal to the electrical gradient
the is an asymmetric distribution of sodium and potassium ions
there can be no separation of ions in solution
all of the above
the is an asymmetric distribution of sodium and potassium ions
A neural tissue has a resting membrane potential of -75 mV. Opening the K* channels will most likely result in depolarization repolarization hyperpolarization initiation of an action potential no change in membrane potential
hyperpolarization
Depolarization of an excitable membrane will shift the membrane potential towards
Minus ninety mV (-90 mV)
Minus eighty-five mV (-85 mV)
Minus seventy mV (-70 mV)
Zero (0)
Zero 0
Nodes of Ranvier are
Interruptions in the myelin sheath along the course of a myelinated axon
Collections of immune cells in the CNS
Satellite cells that support neuron cell bodies in ganglia
Gaps between choroid plexuses where cerebral spinal fluid emerges
None of the above
Gaps between choroid plexuses where cerebral spinal fluid emerges
The threshold of a neuron is the
Total amount of neurotransmitter. it takes to cause an action potential
Voltage that triggers activation of voltage-gated channels
Time between binding of the neurotransmitter and firing of an action potential
Voltage that triggers activatic
gated channels. You selectec
Voltage across the resting cell membrane
Voltage that triggers activation of voltage-gated channels
