Nervous System chapter 4 Flashcards
A polarized membrane has an electrical […] across the cell membrane
A polarized membrane has an electrical potential difference across the cell membrane
Electrical potential difference = voltage
A/an [type of synapse] communicates using chemical messengers (neurotransmitters)
A chemical synapse communicates using chemical messengers (neurotransmitters)
A/an […] is a junction between two nerve cells
A/an synapse is a junction between two nerve cells
An excitatory postsynaptic potential (EPSP) [depolarizes or hyperpolarizes] the cell
An excitatory postsynaptic potential (EPSP) depolarizes the cell
It makes the inside of the cell more positive, bringing the membrane potential closer to its threshold for firing an action potential
An inhibitory post-synaptic potential (IPSP) [depolarizes or hyperpolarizes] the cell
An inhibitory post-synaptic potential (IPSP) hyperpolarizes the cell
It keeps the membrane potential of the postsynaptic neuron below threshold for firing an action potential
At a chemical synapse, an action potential triggers the presynaptic neuron to release […]
At a chemical synapse, an action potential triggers the presynaptic neuron to release neurotransmitters
These molecules bind to receptors on the postsynaptic cell and make it more or less likely to fire an action potential
https://www.khanacademy.org/science/biology/human-biology/neuron-nervous-system/v/neuronal-synapses-chemical
Ca2+ enter the presynaptic cell through […] in the cell membrane
Ca2+ enter the presynaptic cell through voltage-gated calcium channels in the cell membrane
Ca2+ is at a much higher concentration outside the cell. This concentration gradient forces Ca2+ to move into the cell
Cell bodies and dendrites (unmyelinated) make up the [white or grey] matter in the brain
Cell bodies and dendrites (unmyelinated) make up the [white or grey] matter in the brain
Depolarization occurs when […] ions flow in
Depolarization occurs when Na+ ions flow in
This increases the charge inside the cell and results in depolarization of the cell membrane
Electrical synapses are [faster or slower] than chemical synapses
Electrical synapses are faster than chemical synapses
Give 3 ways the signal in a synapse can be terminated
[…] by enzymes
[…] by presynaptic neuron
[…] out of cleft
Give 3 ways the signal in a synapse can be terminated
Breakdown by enzymes
Reuptake by presynaptic neuron
Diffusion out of cleft
Hyperpolarization occurs because K+ channels are […]
Hyperpolarization occurs because K+ channels are slow to close
K+ continues to exit the cell even though resting potential was already reached
In a/an [… synapse], there is a direct physical connection (gap junctions) between the presynaptic neuron and the postsynaptic neuron
In a/an electrical synapse, there is a direct physical connection (gap junctions) between the presynaptic neuron and the postsynaptic neuron
Electrical current in the form of ions flow between the cells
Ionotropic receptors operate via [direct or indirect] neurotransmitter action
Ionotropic receptors operate via direct neurotransmitter action
Membrane-spanning ion channel proteins that open directly in response to ligand binding
K+ concentration is higher [inside or outside] the cell
K+ concentration is higher inside the cell
https://www.khanacademy.org/test-prep/mcat/organ-systems/neuron-membrane-potentials/a/neuron-action-potentials-the-creation-of-a-brain-signal
K+ leaves the cell through […] and […]
K+ leaves the cell through voltage gated K+ channels and leak channels
Metabotropic receptors operate via [direct or indirect] neurotransmitter action
Metabotropic receptors operate via indirect neurotransmitter action
Neurotransmitter binding triggers a signaling pathway, which may indirectly open or close channels
Metabotropic receptors are not themselves ion channels
Myelinated sheaths make up the [white or grey] matter in the brain
Myelinated sheaths make up the white matter in the brain
Na+ concentration is higher [inside or outside] the cell
Na+ concentration is higher outside the cell
Na+ ions enter the cell through […]
Na+ ions enter the cell through voltage-gated Na+ channels
The Na+ concentration gradient is what drives the movement of Na+ ions
Neurons that transmit impulses between other neurons, especially as part of a reflex arc, are called […]
Neurons that transmit impulses between other neurons, especially as part of a reflex arc, are called interneurons
Repolarization occurs when […] ions exit the neuron
Repolarization occurs when K+ ions exit the neuron
Skeletal muscle contraction is initiated by [upper or lower] motor neurons in the spinal cord and brainstem
Skeletal muscle contraction is initiated by lower motor neurons in the spinal cord and brainstem
The amplitude of an action potential is [dependent or independent] of the amount of current that produced it
The amplitude of an action potential is independent of the amount of current that produced it
The bran and spinal cord make up the […] nervous system
The bran and spinal cord make up the central nervous system
The cell membrane is […] permeable to K+ and […] permeable to Na+
The cell membrane is highly permeable to K+ and slightly permeable to Na+
Movement through the leak channels is controlled by concentration gradients
The cell membrane’s resting potential is maintained by the fact that there are [more or less] K+ leak channels than Na+ leak channels
The cell membrane’s resting potential is maintained by the fact that there are more K+ leak channels than Na+ leak channels
This means more K+ will leave the cell compared to the amount of Na+ entering. The cell maintains a negative charge inside
The cells in an electrical synapse are connected by […]
The cells in an electrical synapse are connected by gap junctions
There is a direct physical connection between the presynaptic neuron and the postsynaptic neuron through which ions flow
The main excitatory transmitter in the CNS is […]
The main excitatory transmitter in the CNS is Glutamate
The main inhibitory neurotransmitter in the brain is […]
The main inhibitory neurotransmitter in the brain is GABA
The main inhibitory neurotransmitter in the spinal cord is […]
The main inhibitory neurotransmitter in the spinal cord is glycine
The Na+/ K+ Pump moves Na+ and K+ in the following amounts and directions
[amount] Na+ [direction] the cell
[amount] K+ [direction] the cell
The Na+/ K+ Pump moves Na+ and K+ in the following amounts and directions
3 Na+ out of the cell
2 K+ into the cell
Mnemonic:
3-2-1 NOKIA
3 Na+ Out
2 K+ In
1 ATP used
Pumps ions against their concentration gradient
Helps to restore the concentration gradient and restore the resting potential across the cell membrane
The nervous system outside the brain and spinal cord is the […] nervous system
The nervous system outside the brain and spinal cord is the peripheral nervous system
The primary neurotransmitter at neuromuscular junctions is […]
The primary neurotransmitter at neuromuscular junctions is Acetylcholine
The resting membrane potential (voltage) of a cell is approximately […] mV
The resting membrane potential (voltage) of a cell is approximately -70 mV
The somatic nervous system is [voluntary or involuntary]
The somatic nervous system is voluntary
Associated with the voluntary control of body movements via skeletal muscles
The […] nervous system controls our rest and digest functions
The parasympathetic nervous system controls our rest and digest functions
Remember P for Parasympathetic: “Relaxing and having a Piña colada on beach”
The […] nervous system controls our fight or flight response
The sympathetic nervous system controls our fight or flight response
When a membrane is depolarized, the membrane potential becomes more [positive or negative] compared to its resting potential
When a membrane is depolarized, the membrane potential becomes more positive compared to its resting potential
When multiple presynaptic neurons release neurotransmitters at the same time and trigger an action potential, it is known as […]
When multiple presynaptic neurons release neurotransmitters at the same time and trigger an action potential, it is known as spatial summation
When one presynaptic neuron releases multiple neurotransmitters over a period of time and trigger an action potential, it is known as […]
When one presynaptic neuron releases multiple neurotransmitters over a period of time and trigger an action potential, it is known as temporal summation
When the membrane potential is depolarized during an action potential, it reaches a peak of around […] mV
When the membrane potential is depolarized during an action potential, it reaches a peak of around +40 mV
[…] is the mechanism by which electrical signals travel through the nervous system
Action potential is the mechanism by which electrical signals travel through the nervous system
[…] neurons ascend the spinal cord and carry sensory information to the brain
Afferent neurons ascend the spinal cord and carry sensory information to the brain
[…] form the blood-brain barrier
Astrocytes form the blood-brain barrier
They help control solutes moving from bloodstream to nervous tissue
_____ enters the presynaptic cell and allows vesicles with neurotransmitters inside to fuse with the axon terminal membrane
Ca2+ enters the presynaptic cell and allows vesicles with neurotransmitters inside to fuse with the axon terminal membrane
The neurotransmitters release into the synaptic cleft
[…] neurons exit the spinal cord and bring signals from the brain to the muscles and glands
Efferent neurons exit the spinal cord and bring signals from the brain to the muscles and glands
[…] form the barrier between cerebrospinal fluid and interstitial fluid of the CNS
Ependymal cells form the barrier between cerebrospinal fluid and interstitial fluid of the CNS
[…] surround neurons and provide support and insulation
Glial cells surround neurons and provide support and insulation
[…] is when the membrane potential dips below the resting potential
Hyperpolarization is when the membrane potential dips below the resting potential
While hyperpolarized, the neuron is in a refractory period during which another stimulus given to the neuron (no matter how strong) will not lead to a second action potential
[…] is an electrical potential difference between the inside and outside of a cell
Membrane potential is an electrical potential difference between the inside and outside of a cell
Imagine taking two electrodes and placing one on the inside and the other on the outside of the plasma membrane. If you did this, you would measure an electrical potential difference, or voltage, between the electrodes
[…] digest waste in CNS
Microglia digest waste in CNS
[…] are stored in synaptic vesicles and are released when Ca2+ enters the axon terminal in response to an action potential
Neurotransmitters are stored in synaptic vesicles and are released when Ca2+ enters the axon terminal in response to an action potential
[…] make myelin in CNS
Oligodendrocytes make myelin in CNS
[…] make myelin in PNS
Schwann cells make myelin in PNS
[… nerves] arise from the spinal cord and are distributed in the other parts of the body such as the skin, skeletal muscles, and blood vessels
Spinal nerves arise from the spinal cord and are distributed in the other parts of the body such as the skin, skeletal muscles, and blood vessels
For each of the following neuron structures, provide a brief description of its purpose:
Axon:
Axon hillock:
Dendrite:
Myelin sheath:
Soma:
Synaptic bouton:
What is a collection of cell bodies called in the CNS? In the PNS?
CNS:
PNS:
Which two types of glial cells, if not properly functioning, will make an individual most susceptible to a CNS infection?
Guillain-Barré syndrome (GBS) is an autoimmune disease that causes demyelination in the peripheral nervous system. What type of glial cell is being targeted in GBS?
What neural structure initiates the action potential?
Axon Hillock
What entity maintains the resting membrane potential? What is the approximate voltage of the resting membrane potential?
What is the difference between temporal and spatial summation?
Temporal summation:
Spatial summation:
During the action potential, which ion channel opens first? How is this ion channel regulated? What effect does the opening of this channel have on the polarization of the cell?
Ion channel:
Regulation:
Effect on polarization:
During the action potential, which ion channel opens second? How is this ion channel regulated? What effect does the opening of this channel have on the polarization of the cell?
Ion channel:
Regulation:
Effect on polarization:
What is the difference between the absolute and relative refractory period?
Absolute refractory period:
Relative refractory period:
What ion is primarily responsible for the fusion of neurotransmitter- containing vesicles with the nerve terminal membrane?
What are the three main methods by which a neurotransmitter’s action can be stopped?
What parts of the nervous system are in the central nervous system (CNS)? Peripheral nervous system (PNS)?
CNS:
PNS:
What do afferent neurons do? Efferent neurons? Afferent:
Efferent:
What functions are accomplished by the somatic nervous system? The autonomic nervous system?
Somatic:
Autonomic:
What are the effects of the sympathetic nervous system? The parasympathetic nervous system?
Sympathetic:
Parasympathetic:
What is the pathway of neural impulses in a monosynaptic reflex? In a polysynaptic reflex?
Monosynaptic reflex:
Polysynaptic reflex:
- Resting membrane potential depends on:
I. differential distribution of ions across the axon membrane.
II. the opening of voltage-gated calcium channels. III. active transport of ions across the membrane.
A. I only
B. I and II only C. I and III only D. II and III only
- All of the following are associated with the myelin sheath EXCEPT:
A. faster conduction of nerve impulses.
B. nodes of Ranvier forming gaps along the axon.
C. increased magnitude of the potential difference during an action potential. D. saltatory conduction of action potentials.
- Which of the following is true with regard to the action potential?
A. All hyperpolarized stimuli will be carried to the axon terminal without a decrease in size.
B. The size of the action potential is proportional to the size of the stimulus that produced it.
C. Increasing the intensity of the depolarization increases the size of the impulse.
D. Once an action potential is triggered, an impulse of a given magnitude and speed is produced.
- Which of the following correctly describes a difference between nerves and tracts?
A. Nerves are seen in the central nervous system; tracts are seen in the peripheral nervous system.
B. Nerves have cell bodies in nuclei; tracts have cell bodies in ganglia.
C. Nerves may carry more than one type of information; tracts can only carry
one type of information.
D. Nerves contain only one neuron; tracts contain many neurons.
- Which of the following accurately describes sensory neurons?
A. Sensory neurons are afferent and enter the spinal cord on the dorsal side. B. Sensory neurons are efferent and enter the spinal cord on the dorsal side. C. Sensory neurons are afferent and enter the spinal cord on the ventral side. D. Sensory neurons are efferent and enter the spinal cord on the ventral side.
- When a sensory neuron receives a stimulus that brings it to threshold, it will do all of the following EXCEPT:
A. become depolarized.
B. transduce the stimulus to an action potential.
C. inhibit the spread of the action potential to other sensory neurons.
D. cause the release of neurotransmitters onto cells in the central nervous system.
- When the potential across the axon membrane is more negative than the normal resting potential, the neuron is said to be in a state of:
A. depolarization.
B. hyperpolarization.
C. repolarization.
D. polarization.
- Which of the following statements concerning the somatic division of the peripheral nervous system is INCORRECT?
A. Its pathways innervate skeletal muscle.
B. Its pathways are usually voluntary.
C. Some of its pathways are referred to as reflex arcs. D. Its pathways always involve more than two neurons.
- Which of the following is a function of the parasympathetic nervous system? A. Increasing blood sugar during periods of stress
B. Dilating the pupils to enhance vision
C. Increasing oxygen delivery to muscles
D. Decreasing heart rate and blood pressure
- Which of the following neurotransmitters is used in the ganglia of both the
sympathetic and parasympathetic nervous systems? A. Acetylcholine
B. Dopamine
C. Norepinephrine
D. Serotonin
- In which neural structure are ribosomes primarily located? A. Dendrites
B. Soma
C. Axon hillock D. Axon
- An autoimmune disease attacks the voltage-gated calcium channels in the synaptic terminal of an excitatory neuron. What is a likely symptom of this condition?
A. Spastic paralysis (inability to relax the muscles)
B. Flaccid paralysis (inability to contract the muscles) C. Inability to reuptake neurotransmitters once released D. Retrograde flow of action potentials
- A neuron only fires an action potential if multiple presynaptic cells release neurotransmitters onto the dendrites of the neuron. This is an example of:
A. saltatory conduction. B. summation.
C. a feedback loop.
D. inhibitory transmission.
- A disease results in the death of Schwann cells. Which portion of the nervous system is NOT likely to be affected?
A. Central nervous system
B. Somatic nervous system
C. Autonomic nervous system
D. Parasympathetic nervous system
- A surgeon accidentally clips a dorsal root ganglion during a spinal surgery. What is a likely consequence of this error?
I. Loss of reflexes at that level II. Loss of sensation at that level
III. Loss of cognitive function A. I only
B. II only
C. I and II only
D. I, II, and III
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