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Exam #1- Practice Questions

Terms in this set (91)

Threshold
-55 mV
Resting State
-70 mV
Stimulus
...
Failed Initiations
GRADED POTENTIAL
Depolarization
- charge becomes more positive
- Sodium channels open
- Na+ floods into the cell
Action Potential
...
Repolarization
- charge becomes more negative
- potassium channels open up
- K+ floods out of the cell
Refractory Period
-shortly after the absolute refractory period
- it is a hyper-polarized state
- After a little time, there's a relative refractory period which means if you give a little bit larger than normal stimulation you WILL be able to fire an action potential.
Absolute Refreactory Period
- immediately after an action potential
- NO MATTER WHAT YOU DO , you won't be able to get that part of the axon to refire
hyper-polarization
- "overshoot"
- too much K+ floods out of the cell
- making the cell more negative than the resting state
- The potassium ion channel is also slower to close, which leads to a hyper-polarized state (the overshoot) before returning to its normal resting state (-70mV)
Resting State
...
+40 mV
...
0 mV
...
Time (ms)
...
Voltage (mV)
...
Sketch out the organization of the nervous system. Differentiate between the central and peripheral branches.
Nervous System:
1.) Central Nervous System
- brain
- spinal cord
2.) Peripheral Nervous System
a.)Somatic Nervous System
-cranial nerves
- spinal nerves
b.) Autonomic Nervous System
b1.) Sympathetic Nervous System
- fight-or-fight
b2.) Parasympathetic Nervous System
- Rest-and-Digest
c.)Enteric Nervous System
- GI system
Describe the two branches of the autonomic nervous system and their roles
1.) Sympathetic Nervous System --> Fight or Flight
2.) Parasympathetic Nervous System --> Rest and Digest
Explain the gut-brain axis. Why is the gut-brain axis important?
- The gut and the brain interact
- They both can impact each other
- They communicate using the microbiome, where a balance or an imbalance can occur, or signaling can happen among the microbiota to convey messages between the gut and the brain
- It is important because the imbalance of the gut or the brain impacts the other
What is a perceptual world? What is the importance of a perceptual world?
- Our own personal reality that our brain constructs together from sensory input
- It is important for our coordination of our responses to the environment and mediating behavior
What is neuroplasticity and why is it a necessary feature of nervous system functioning?
- Our brain is plastic and moldable
- You can grow or get rid of neural connections based on frequency and need
- Its necessary to be able to change and grow as our environments change
- We need to be able to change to meet new demands
What is cortical asymmetry? Include two specific examples in your response
- It means that structures are NOT mirror images on both sides
- Asymmetry is needed for integrative tasks like:
1.) Language (left hemisphere is prominent)
2.)Navigation (Right hemisphere is prominent)
What does it mean to say that brain systems are organized hierarchically and in parallel?
- Brain systems are hierarchically organized meaning some things are processed from least to most complex
- While, brain systems are also organized in parallel, meaning other things are processed individually but at the same time
- Subsystems of the brain are organized into multiple parallel pathways (multiple levels of functions) and these levels must be parallel, extensively interconnected to integrate information and produce perceptions/movements
Contrast sensory and motor control
Sensory Control:
- incoming signals
- starting edge of the parietal lobe
Motor Control:
- outgoing signals
- back of frontal lobe
Same:
- number of neurons depend on how sensitive body is to sense (touch, sight, etc.)
Are brain functions localized or distributed? Why?
- BOTH LOCALIZED AND DISTRIBUTED
- this is because certain parts are specialized for certain behaviors (localized) but are also integrated.
- Many brains areas are integrated (distributed) and can pick up slack of damaged portion of brain, showing communication and distribution between brain areas
Explain the balance between excitation and inhibition.
- Excitation is INCREASE in neural activity
- Inhibition is DECREASE in neural activity
- they are balanced because in order to make movements you also have to prevent other unwanted movements
The 12 nerve pairs that control sensory and motor functions of the head, neck, and internal organs are called the _________.
a.) cranial nerves
b.) cerebellicular nerves
c.) spinal nerves
d.) root ganglia
a.) cranial nerves
The two classes of nervous system cells are _______.
a.) axons and neurons
b.) glia and dendrites
c.) neurons and glia
d.) axons and dendrites
c.) neurons and glia
A cell that carries efferent information from from the brain and spinal cord to make muscles contract is called a _________.
a.) Interneuron
b.) Purkinje Cell
c.) Motor Neuron
d.) Oligodendrocyte
c.) motor neuron
Neural agenesis refers to:
a.) the failure of a structure to develop
b.) the degeneration of a structure
c.) an injury to a brain structure
d.) the creation of a brain structure
a.) the failure of a structure to develop
ischemic stroke is caused by ________, whereas hemorrhagic stroke is caused by _________.
a.) a broken blood vessel; a clot
b.) a clot; reduced hemoglobins
c.) bleeding/rupture; encephalitis
d.) a clot; a broken blood vessel
d.) a clot; a broken blood vessel
What is the microbiome?
a.) the neurotransmitters located in the gut
b.) the micro environment of the brain
c.) a mechanism for removal of invasive microbiota from the body
d.) the bacteria located in the gut
d.) the bacteria located in the gut
Spatial navigation is controlled predominantly by.....
a.) the right hemisphere
b.) the left hemisphere
c.) the left and right hemisphere working together to direct purposeful movement
d.) none of these are correct
a.) the right hemisphere
If a monkey received lateral hypothalamus lesions as part of an experimental manipulation, what would happen?
a.) the monkey would increase its food intake substantially and become obese
b.) the monkey would dramatically decrease its food intake, have a dangerously low body weight, and be at risk of fatal starvation
c.) the monkey would have to be humanely euthanized
d.) the monkey would have reduced sensitivity of Ca2+ channels, and thus less neurotransmitter release when feeding
b.) the monkey would dramatically decrease its food intake, have a dangerously low body weight, and be at risk of fatal starvation
REMEMBER:
- lateral hypothalamus ---> LEAN
- ventromedial hypothalamus ----> VERY FAT
Agenesis of the cerebellum likely would result in all the following except:
a.) Motor disturbances (e.g. problems with balance or gait)
b.) Distinctive pattern of speaking
c.) Difficulty with routine activities, such as personal hygiene
d.) Improvement in cognitive abilities over time
c.) Difficulty with routine activities, such as personal hygiene
- the video of Chris with ataxia, he was shown shaving his face and brushing teeth with no issues
What type of meningitis is most serious and why?
a.) Viral because it lasts 7 to 10 days and most patients, although they survive, have long-term deficits that severely hinder their quality of life
b.) Bacterial because it progresses very quickly, leading to sepsis and a high mortality rate
c.) Viral because bacterial meningitis can be treated with high-dose, broad-spectrum antibiotics
d.) Bacterial because the inflammatory response associated with infection of the meninges layers and cerebral spinal fluid
b.) bacterial because it progresses very quickly, leading to sepsis and a high mortality rate
As Molly is walking across campus, a car swerves toward her. Her heart races and sweat breaks out as she jumps out of harm's way. This mobilization of energy is due to the action of Molly's ______________.
a.) Autonomic nervous system, specifically the parasympathetic division
b.) Autonomic nervous system, specifically the sympathetic division
c.) Central nervous system, specifically interneurons in the spinal cord
d.) Central nervous system, specifically the somatosensory and motor cortexes
b.) Autonomic nervous system, specifically the sympathetic division
Which of the following correctly describes the possible symtoms associated with meningitis?
a.) facial paralysis, limb paralysis, severe headache
b.) severe headache, stiff neck, drowsiness
c.) aggressiveness, mood swings, personality changes
d.) convulsions, vomiting, confusion
b.) severe headache, stiff neck, drowsiness
Tissue plasminogen activator (t-PA) is effective for treating:
a.) hemorrhagic stroke
b.) meningitis
c.) inflammation of the ventricles
d.) ischemic stroke
d.) ischemic stroke
Contraction of the pupils and stimulation of digestion are controlled by:
a.) the parasympathetic nervous system
b.) the sympathetic nervous system
c.) somatic nervous system
d.) efferent and afferent nerves
a.) the parasympathetic nervous system
- rest and digest!!!
The microbiome can be involved in treatment of behavioral disorders through:
a.) removal of invasive microbiota from the body
b.) administration of live microorganisms known as psychobiotics
c.) surgical intervention
d.) prescription of antibiotics
b.) administration of live microorganisms known as psychobiotics
Myelin is important for propagating action potential (AP) because:
a.) it increases the conduction speed of the action potential
b.) it conserves energy
c.) it reduces the need for sodium and potassium
d.) it both increases the conduction speed of the action potential as well as conserves energy
d.) it both increases the conduction speed of the action potential as well as conserves energy
Ependymal cells are associated with the:
a.) blood-barrier barrier
b.) production of myelin
c.) production of cerebral spinal fluid
d.) immune functioning
c.) production of cerebral spinal fluid
Which of the following is true of oligodendrocytes?
a.) Oligodendrocytes are essential for healthy immune system functioning
b.) Oligodendrocytes carry sensory information in the peripheral nervous system
c.) Oligodendrocytes can be star-shaped or egg-shaped
d.) A single oligodendrocyte can form myelin on several axons in the central nervous system
d.) A single oligodendrocyte can form myelin on several axons in the central nervous system
Which of the following is true of neurons:
a.) they usually have several axons
b.) they are all remarkably similar in size
c.) each has only one axon
d.) they all have the same number of dendrites
c.) each has only one axon
Greg accidentally cuts his fingertip with a knife. The next day he notices that his fingertip seems numb to the touch. Greg is very concerned about this, but you tell him not to worry because:
A) nerves in the PNS regenerate thanks to Schwann cells.
B) nerves in the CNS regenerate thanks to Schwann cells.
C) nerves in the CNS regenerate thanks to oligodendroglial cells.
D) nerves in the PNS regenerate thanks to oligodendroglial cells
a.) nerves in the PNS regenerate thanks to Schwann cells
Phagocytosis, or the breakdown of any foreign tissue or dead bran cells, is carried out by:
a.) astrocytes
b.) ependymal cells
c.) microglial cells
d.) oligodendroglial cells
c.) microglial cells
Which of the following represents the normal order of activation (i.e., information flow) in neuronal transmission?
a.) cell body-->axon-->dendrite-->axon terminal
b.) axon terminals-->cell body--> axon--> dendrite
c.) axon-->dendrite--> cell body--> axon terminals
d.) dendrite --> cell body--> axon--> terminal button
d.) dendrite-->cell body-->axon--> terminal button
When neurons are continuously firing, they need a constant supply of glucose and oxygen to continue operating. This is achieved via ______, which signal blood vessels to expand and increase blood flow.
a.) microglia
b.) astrocytes
c.) Schwann cells
d.) ependymal cells
b.) astrocytes
A change in the resting potential from -70 mV to -83 mV is called:
a.) nothing, as these changes occur spontaneously.
b.) hyper-polarization.
c.) graded inhibitory potential
d.) depolarization.
e.) graded excitatory potential.
b.) hyper-polarization.
At rest, the concentrations of _____ are higher inside of a neuron, whereas the concentrations of _____ are higher outside of a neuron.
a.) potassium (K+); chloride (Cl-)
b.) potassium (K+); sodium (Na+)
c.) potassium (K+); anions (A-)
d.) sodium (Na+); potassium (K+)
b.) potassium (K+); sodium (Na+)
Inhibitory postsynaptic potentials (IPSPs) are associated with:
a.) the opening of sodium channels, allowing the influx of sodium.
b.) the closing of potassium channels, stopping the influx of potassium.
c.) the opening of potassium channels, allowing the outflow of potassium.
d.) the closing of sodium channels, stopping the influx of potassium.
c.) the opening of potassium channels, allowing the outflow of potassium.
An action potential usually goes only in one direction in an axon because:
a.) the refractory periods force the impulse to go in one direction.
b.) the ion flow is attracted to chemicals in the synaptic knob.
c.) the ions can flow only in one direction.
d.) autoreceptors inhibit backward flow of ions.
a.) the refractory periods force the impulse to go in one direction.
A large, brief reversal in the polarity of an axon membrane is called a(n) ______.
a.) action potential
b.) threshold potential
c.) resting potential
d.) graded potential
e.) EPSP
a.) action potential
The increase in the activity of a neuron or brain area is called _____.
a.) consciousness
b.) sensation
c.) excitation
d.) inhibition
e.) action potential
c.) excitation
_____ channels are more sensitive than _____ channels, so they open first during the action potential.
a.) All channels are equally sensitive.
b.) Potassium; calcium
c.) Calcium; potassium
d.) Sodium; potassium
d.) Sodium; potassium
_____ channels are less sensitive than _____ channels, so during an action potential, they open more slowly but remain open longer.
a.) Potassium; sodium
b.) Calcium; sodium
c.) Chloride; sodium
d.) Sodium; potassium
a.) Potassium; sodium
Action potentials originate in the:
a.) dendrites.
b.) axon.
c.) cell body.
d.) initial segment (axon hillock).
d.) initial segment (axon hillock).
EPSPs are associated with:
a.) the opening of sodium channels, allowing the influx of sodium.
b.) the closing of sodium channels, stopping the influx of potassium.
c.) the opening of potassium channels, allowing the outflow of potassium.
d.) the closing of potassium channels, stopping the influx of potassium.
a.) the opening of sodium channels, allowing the influx of sodium.
The resting potential of the inside of an axon, relative to the outside:
a.) can vary from -40 mV to -90 mV depending on the species and preparation.
b.) is -70 mV in all preparations.
c.) is -70 mV in all species.
d.) can vary from -40 mV to -90 mV within a species.
a.) can vary from -40 mV to -90 mV depending on the species and preparation.
To measure the voltage across the cell membrane, you would normally:
a.) place two electrodes on the outer surface of the axon's membrane and measure the voltage difference.
b.) insert two electrodes into the axon and measure the voltage difference.
c.) all of these are correct
d.) place one electrode on the outer surface of an axon's membrane and another inside the axon and measure the voltage difference.
d.) place one electrode on the outer surface of an axon's membrane and another inside the axon and measure the voltage difference.
Nerve impulse describes:
a.) input at the dendrites of a cell.
b.) the movement of an action potential along the axon.
c.) an action potential along the combined axons, which are called nerves.
d.) an action potential crossing the synaptic cleft.
b.) the movement of an action potential along the axon.
An action potential is:
a.) a large graded potential.
b.) seldom shorter than 10 milliseconds.
c.) the same as a threshold potential.
d.) a large, brief reversal in the polarity of a membrane.
d.) a large, brief reversal in the polarity of a membrane.
Sodium channels close when the membrane potential reaches approximately:
a.) +40 mV
b.) -50 mV
c.) +70 mV
d.) 0 mV
a.) +40 mV
How does a squid benefit from having unusually large axons?
a.) They boost the squid's immune system.
b.) They enhance the squid's fertility.
c.) They enable the squid to jet-propel away from predators.
d.) They enable the squid to perform complex grasping behavior with its tentacles.
c.) They enable the squid to jet-propel away from predators.
The negative charge inside the cell membrane is largely a product of the presence of negatively charged:
a.) potassium ions.
b.) large proteins.
c.) All of these
d.) sodium ions.
b.) large proteins.
The speed at which nerve impulses travel down an axon are greatly increased by:
a.) the length of the axon.
b.) refractory periods.
c.) calcium channels.
d.) myelin.
d.) myelin.
The propagation of the nerve impulse is:
a.) similar to the effect of falling dominoes.
b.) not decremental.
c.) All of these are correct.
d.) related to the opening of potassium and sodium ion channels.
c.) All of these are correct.
The _____ acts in a way similar to a democracy in that it "counts votes" from incoming EPSPs and IPSPs, and if there is enough excitation, an action potential will fire.
a.) ion channel
b.) axon hillock
c.) dendrite
d.) soma
b.) axon hillock
The basis of electrical activity in nerves is the:
a.) movement of extracellular fluid.
b.) elongation and contraction of axons.
c.) movement of intracellular and extracellular ions.
d.) equilibrium between intracellular and extracellular ions.
c.) movement of intracellular and extracellular ions.
Melissa, a 23-year-old woman, has been having tingling sensations in her right arm and leg for a few weeks. Today, when she woke up, she realized that she could barely move her right arm. She had a similar set of symptoms a couple of years ago, but they went away, so she thought everything was fine. Your advice to Melissa is to go to the doctor because she may have:
a.) a brain tumor.
b.) meningitis.
c.) multiple sclerosis.
d.) early onset stroke.
c.) multiple sclerosis.
Channels in the cell membrane are formed by:
a.) protein molecules.
b.) potassium ions.
c.) lipids.
d.) sodium ions.
a.) protein molecules.
Saltatory conduction is aided by _____ located at the _____.
a.) sodium and potassium channels; nodes of Ranvier
b.) sodium-potassium pumps; terminal buttons
c.) calcium channels; nodes of Ranvier
d.) glial cells; nodes of Ranvier
a.) sodium and potassium channels; nodes of Ranvier
Because of refractory periods, the maximum firing rate of a neuron is approximately _____ impulses per second.
a.) 1000
b.) 500
c.) 200
d.) 5
c.) 200
EPSPs are associated with _____, whereas IPSPs are associated with _____.
a.) opening of sodium channels; opening of potassium channels
b.) opening of calcium channels; closing of potassium channels
c.) closing of sodium channels; opening of potassium channels
d.) opening of sodium channels; closing of potassium channels
a.) opening of sodium channels; opening of potassium channels
The magnitude of an action potential (AP) is measured near the axon hillock using an electrode and then measured again 2 mm farther down the axon. Compared to the AP measured near the axon hillock, the AP 2 mm farther down the axon is:
a.) smaller.
b.) larger.
c.) of the same magnitude.
d.) completely nullified.
c.) of the same magnitude.
Na+ and K+ channels on axons are:
a.) mainly calcium dependent.
b.) mainly voltage dependent.
c.) none of these
d.) mainly ligand dependent.
b.) mainly voltage dependent.
The repolarization of the neuronal membrane is largely due to the:
a.) closing of sodium channels, stopping the outflow of sodium.
b.) closing of calcium channels, stopping the influx of calcium.
c.) closing of potassium channels, stopping the influx of potassium.
d.) opening of potassium channels, allowing the outflow of potassium.
d.) opening of potassium channels, allowing the outflow of potassium.
Autoimmune diseases are illnesses resulting from:
a.) the body attacking substances and tissues that are normally present in the body.
b.) the inability of the immune system to fight off harmful substances in the body.
c.) the production of too many antibodies when fighting off an outside infection.
d.) the degeneration of the immune system.
a.) the body attacking substances and tissues that are normally present in the body.
The action potential normally consists of the summed current changes caused by the _____ and the _____.
a.) inflow of sodium; outflow of potassium
b.) inflow of sodium; outflow of chloride
c.) outflow of sodium; inflow of potassium
d.) inflow of calcium; outflow of potassium
a.) inflow of sodium; outflow of potassium
Which of the following is NOT involved in producing the resting potential?
a.) chloride ions
b.) calcium ions
c.) potassium ions
d.) sodium ions
b.) calcium ions
A chemical with an excitatory or inhibitory effect when released by a neuron onto a target is called a(n) ____.
a.) messenger
b.) molecule
c.) neurotransmitter
d.) vesicle
e.) impulse
c.) neurotransmitter
A brief hyper-polarization of the neuronal membrane that makes it less likely that the neuron will fire an action potential is called:
a.) an inhibitory postsynaptic potential (IPSP).
b.) an excitatory postsynaptic potential (EPSP).
c.) spatial summation.
d.) saltatory conduction.
a.) an inhibitory postsynaptic potential (IPSP).
A change in the resting potential from -70 mV to -55 mV typically results in:
a.) an excitatory postsynaptic potential.
b.) hyper-polarization.
c.) an action potential.
d.) repolarization.
c.) an action potential.
EPSPs and IPSPs are first received by:
a.) dendrites.
b.) the soma.
c.) the axon hillock.
d.) the neuronal membrane.
a.) dendrites.
Which of the following is NOT one of the important reasons for refractory periods in neurons?
a.) They limit the firing rate of the neuron.
b.) They increase the sensitivity of the neuron.
c.) They allow time for the neuron to reset prior to another action potential.
d.) They force nerve impulses to travel in one direction.
b.) They increase the sensitivity of the neuron.
The symptoms of multiple sclerosis are caused by:
a.) loss of myelin around axons.
b.) excess myelin on axons.
c.) excess excitatory input.
d.) excess inhibitory input.
a.) loss of myelin around axons.
A(n) _____ channel only opens or closes at specific membrane voltages.
a.) ligand-gated
b.) relatively refractory
c.) absolutely refractory
d.) voltage-gated
e.) nerve impulse
d.) voltage-gated
The voltage of a neural membrane that is sufficient to cause an action potential is approximately _____; it is called a _____.
a.) 50 mV; graded potential
b.) -65 mV; threshold potential
c.) -55 mV; threshold potential
d.) 70 mV; resting potential
c.) -55 mV; threshold potential
Excitatory postsynaptic potentials (EPSPs) are recorded:
a.) at the synaptic knob.
b.) in the axon.
c.) from the cell body.
d.) in the terminal buttons.
c.) from the cell body.
Autoimmune diseases are illnesses resulting from:
a.) the production of too many antibodies when fighting off an outside infection.
b.) the degeneration of the immune system.
c.) the inability of the immune system to fight off harmful substances in the body.
d.) the body attacking substances and tissues that are normally present in the body.
d.) the body attacking substances and tissues that are normally present in the body.
For an EPSP to cause another action potential, the stimulation must reach the _____, which is (are) rich in voltage-sensitive ion channels.
a.) cell body
b.) terminal buttons
c.) dendrites
d.) initial segment/axon hillock
d.) initial segment/axon hillock
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