Ch. 12 - nervous tissue
Typically, the resting membrane potential of a neuron is
-70 mV
Initially, the voltage-gated Na+ channels are closed and the membrane potential is ______ mV. As Na+ flows in the membrane potential changes to ______ mV and the threshold is reached. -70; -90 -70; -55 -90; -70 -55; -70
-70; -55
The voltage gated sodium channels undergo changes in activity during the depolarization phase of an action potential. Place them in order from firsr to last. 1. The membrane potential is -70 mv 2. Voltage gated sodium ion channels open 3. Sodium ions flow into the neuron 4. The membrane potential becomes more positive
1, 3, 4, 2
1 is 2 is 3 is 4 is
1. Bipolar neuron 2. Anaxonic neuron 3. Unipolar neuron 4. Multipolar neuron
1 is 2 is 3 is 4 is 5 is
1. Chemically gated channels 2. Leak channels 3. Pump 4. Voltage gated channels 5. Pump
Place the events of an EPSP in order. 3. The inside of the cell becomes more positive 1. Excitatory neurotransmitter binds to chemically gated cation channel 2. More Na+ enters the postsynaptic cell than K+ leaves 4. The local current of Na+ becomes weaker as it moves a towards the axon hillock
1. Excitatory neurotransmitter binds to chemically gated cation channel 2. More Na+ enters the postsynaptic cell than K+ leaves 3. The inside of the cell becomes more positive 4. The local current of Na+ becomes weaker as it moves towards the axon hillock
1 is 2 is 3 is
1. Sensory neuron 2. Interneuron 3. Motor neuron
A is B is C is D is E is
A- axon B- neurolemmocyte C- endoneurium D- perineurium E- epineurium
A is B is C is D is
A- dendrites B- axon C- axon collateral D- terminal extensions
A. B. C. D. E.
A. Dendrite B. Axon hillock C. Telodendria D. Nucleolus E. Synaptic knobs
Pain receptors in the skin send signals to the CNS for processing. These pain receptors are an example of ____ neurons Afferent Association Multipolar Efferent
Afferent
The fundamental physiological properties that enable nerve cells to communicate with other cells are The ability to respond to environmental changes. The ability to produce electrical signals that are quickly conducted to other cells at distant locations. The ability to secrete a chemical that will stimulate the next cell when an electrical signal reaches the end of an axon. All of these choices are correct.
All of these choices are correct
Glycine is a
Amino acid
Movement away from the cell body is
Anterograde transport
Which glial cells is starlike in shape and helps form the blood-brain barrier? Ependymal cells Astrocytes Oligodendrocytes Microglial cells
Astrocytes
Where are synaptic knobs located?
At the distal ends of an axons
Common types of neurons with where they can be found: Special senses
Bipolar neurons
The presence of ___ ions causes the synaptic vesicles to bind to the membrane, allowing neurotransmitters to be released Chloride Calcium Potassium Sodium
Calcium
When a neurotransmitter binds a protein channel, it opens and lets sodium diffuse down its concentration gradient. This is an example of Sodium pump Voltage gated sodium channel Leakage channel Chemically gated sodium channel
Chemically gated sodium channel
Synapses are classified as Electrical synapses Mechanical synapses Chemical synapses
Electrical synapses Chemical synapses
Neuropeptide is a
Enkephalin
____ is a responsiveness to a stimuli Amiotic Excitability Conductivity Secretion
Excitability
The functions of the astrocytes are to Help form the blood-brain barrier Produce cerebrospinal fluid Myelinate axons of the PNS Regulate the composition of the interstitial fluid Assist neuronal development
Help form the blood-brain barrier Assist neuronal development Regulate the composition of the interstitial fluid
Glial cells are found ___ In both the central and peripheral nervous systems Only within the peripheral nervous system Only within the central nervous system
In both the central and peripheral nervous system
The electrical gradient in a resting neuron is such that the ___ of the cell is negative relative to the ___
Inside; outside
During an action potential, voltage-gated potassium channels open after voltage-gated sodium channels. The effect this had on the membrane potential is It becomes less positive and more negative It becomes more positive It has no effect on the membrane potential
It becomes less positive and more negative
Common types of neurons with where they can be found: Most common type; innervate muscles and glands
Multipolar neurons
The threshold is reached when the ____ ions flow into the cell Ca2+ Cl- Na+ K+
Na+
The nerve impulse has the voltage-gated ______ channels opened first followed by the opening of the voltage-gated ______ channels. Na+; K+ K+; Na* Na+; Cl- K+; Cl-
Na+ and K+
Which of the following pumps can you find in the plasma membrane? Ca2+ H+ Na+/K+ Cl-
Na+/K+ Ca2+
A ___ is the propagation of an action potential along an axon Depolarized neuron Graded potential Depolarized neuron Nerve impulse
Nerve impulse
What type of cels produce the myelin sheath in the central nervous system (CNS)? Neurolemmocytes Astrocytes Oligodendrocytes Microglia
Oligodendrocytes
The sequential opening of voltage gated sodium channels is followed by the sequential opening of voltage gated ___ channels
Potassium
The flow of ______ ion is the most common cause of depolarization. Sodium Chloride Calcium Potassium
Sodium
Which of the following membrane transporters are present throughout the membrane of a neuron? Potassium leak channels Voltage gated sodium channels Voltage gated potassium channels Sodium leak channels Na+/K+ pumps
Sodium leak channels Na+/K+ pumps Potassium leak channels
Which part of the neuron contains the nucleus?
Soma
Which part of a neuron contains calcium pumps and channels? Synaptic bulbs Soma Dendrites Axon
Synaptic bulbs
"An action potential either happens or it doesn't" this statement could also be called ___ The threshold law The all-or-none-law The refractory law
The all-or-none law
The two factors that affect PNS regeneration are ____ The amount of damage The distance between injury site and the effector organ Rate of microglial cell division Presence of ependymal cells
The amount of damage The distance between injury and the effector organ
The myelin sheath covers ___ The axon The choroid plexus The nerve The cell body
The axon
Which describes the propagation of depolarization down an axon? Sodium flows into the cell in one region and backs out again at another region The flow of Na+ into adjacent regions causes potassium channels to open Sodium influx triggers sodium efflux The flow of Na+ to downstream regions cause depolarization of adjacent regions
The flow of Na+ to downstream regions causes depolarization of adjacent regions.
What do all glial cells have in common?
They assist neurons in their respective functions
The all-or-none law refers to the fact that action potential will only occur if the initial segment reaches ___
Threshold
TRUE OR FALSE For regeneration of a damaged axon in the PNS, the cell body must be intact
True
True or false: Graded potentials vary in size depending on the stimulus
True
True or false: Voltage gated sodium ion channels are closed initially and the membrane potential is -70 mv
True
Common types of neurons with where they can be found: Most neurons in the PNS
Unipolar neurons
If extracellular calcium was absent, which would likely be true? Vesicles containing Neurotransmitter would not merge with the plasma membrane Voltage gated calcium channels would not open on the synaptic knob An action potential could not propagate itself down the axon The electrochemical gradient for sodium would be destroyed
Vesicles containing neurotransmitter would not merge with the plasma membrane.
Membrane pumps require ___ energy A lot of No
a lot of
Conductive activity in a neuron generally causes it to secrete
a specific neurotransmitter that either excites or inhibits its target.
Which occurs first? Absolute refractory period Relative refractory period
absolute refractory period
Glutamate is an ______
amino acid
Action potentials are always propagated along an axon at the same ____ but ___ can vary depending on the strength of the stimulus Amplitude; frequency Frequency; amplitude
amplitude; frequency
The nerve impulse causes ___ in the number of calcium ions that enter the synaptic knob An increase A decrease
an increase
What is the most abundant glial cell in the CNS?
astrocyte
___ are star shaped Ependymal cells Astrocytes Satellite cells Microglial cells
astrocytes
A nerve is a bundle of parallel
axons
Cytoplasm within an axon is called Axoplasm Axolemma Nissl substance
axoplasm
A synapse is a junction Between cell bodies Between neurotransmitters Between a neuron and another cell
between a neuron and another cell
Many excitatory neurotransmitters cause the opening of channels that allow for the flow of ______. Both Na+ and K+ Cl- only K+ only Na+ only
both Na+ and K+
The central nervous system is made of the ____ and spinal ___
brain; cord
Acetylcholinesterase Binds to nicotinic receptors Catalyzes hydrolysis of ACh to remove it from the synaptic cleft Blocks muscarinic receptors Catalyzes resynthesis of ACh
catalyzes hydrolysis of ACh to remove it from the synaptic cleft.
Consists of the brain and spinal cord
central nervous system
The brain and spinal cord are part of the ____ Peripheral nervous system Sensory nervous system Motor nervous system Central nervous system
central nervous system
Ependymal cells help produce An immune response against pathogens Cerebrospinal fluid The blood-brain barrier Myelin in the CNS
cerebrospinal fluid
The ependymal cells help produce ___ Urine White blood cells Cerebrospinal fluid Blood plasma
cerebrospinal fluid
Receptors are parts of the nervous system that allow it to
collect information
The total length of the axon is called the ___ segment
conductive
The main activity of the ___ is the propagation of an action potential along the axolemma Terminal segment Initial segment Conductive segment
conductive segment
A positive change in the membrane potential is called Inactivation Depolarization Repolarization Hyperpolarization
depolarization
Another way for the neurotransmitter to be removed from the synaptic cleft is by ___ where there is uptake by surrounding glial cells Reuptake Extrusion Diffusion
diffusion
Glial cells ______ transmit electrical impulses. Do not Do
do not
The nervous system controls the activity of muscles and glands. Muscles and glands can generate changes and are therefore called
effectors
Neurons that carry signals from the CNS to skeletal muscle for contraction would be classified as ___ neurons Unipolar Bipolar Efferent Afferent
efferent
Creating and transmitting ___________ currents is central to the function of neuron physiology
electrical
A difference in the number of charged particles between two sides of the membrane forms a(n) ___ Electrical gradient Sodium gradient Chemical gradient
electrical gradient
The choroid plexus is made from capillaries and ___ Ependymal cells Astrocytes Microglial cells Ogliodendrocytes
ependymal cells
A larger axon transmits an impulse ______ than a smaller axon. Slower Faster
faster
A potential that is a temporary change in membrane potential which lasts only as long as the stimulus that causes it and can vary in size is called a ___ potential
graded
Neuronal pools are made of ___ Sensory neurons Interneurons Motor neurons
interneurons
The myelin sheath is made of a high percentage of ____ Nucleic acids Lipids Carbohydrates
lipids
Which glial cell acts as a phagocyte? Ogliodendrocytes Ependymal cells Astrocytes Microglial cells
microglial cells
The vagus nerve contains afferent and efferent neurons, therefore it is an example of a(n) __________ nerve. Mixed Afferent Sensory Motor
mixed
Dopamine is a
monoamine
Norepinephrine is a __
monoamine
The brain interprets the increased frequency of nerve signals as a ___ stimulus More intense Less intense
more intense
If there were no sodium leak channels, the resting membrane potential of a neuron would be:
more negative
Based on structure, the most common type of neuron is the _______ neuron.
multipolar
If a neuron has many dendrites and a single axon, it is called a(n) ______ neuron. Bipolar Unipolar Multipolar
multipolar
The most common type of neuron contains many dendrites and a single axon. Structurally, this is classified as a(n) ___ neuron Bipolar Anaxonic Unipolar Multipolar
multipolar
___ neurons are most common Bipolar Multipolar Unipolar
multipolar
What is the primary tissue of the nervous system? Epithelial tissue Connective tissues Nervous tissue Muscle tissue
nervous tissue
Nerve growth factors that stimulate outgrowth of severed axons are secreted by Microglial cells Astrocytes Neurolemmocytes Oligodendrocytes
neurolemmocytes
The ability to alter the response of neurons to neurotransmitters is known as
neuromodulation
Neuronal pools are also called Axosomatic synapses Neuronal pathways Neuronal circuits Synaptic vesicles
neuronal circuits Neuronal pathways
Neuromodulation alters the response of ______ to neurotransmitters. Neurons Glial cells
neurons
The components of nervous tissue that conduct electrical impulses are Blood vessels Neurons Ganglia Glial cells
neurons
______ are released from neurons in response to conductive activity. Electrons Neurotransmitters Mitotic cells Graded potentials
neurotransmitters
The glial cell that myelinates and insulates axons within the CNS is the
oligodendrocyte
A nerve is part of the ______ nervous system. Central Peripheral
peripheral
Includes cranial nerves, spinal nerves, and ganglia
peripheral nervous system
Nerves and ganglia are structures found in the
peripheral nervous system
Myelin sheaths mainly consist of which part of the glial cells that form them? Nucleus Perivascular feet Plasma membranes Cytoplasm
plasma membranes
When sodium enters the neuron via chemically gated sodium channels, the membrane will depolarize. Therefore, the membrane potential will become more Negative Positive
positive
Voltage represents ______ energy. Potential Kinetic Chemical
potential
Propagation of depolarization only flows away from the cell body towards the synaptic knob because ______. Previous regions in the axon have only potassium channels Previous regions of the axon are already repolarized Previous regions in the axon have sodium channels in the inactive state
previous regions in the axon have sodium channels in the inactive state
Chemically gated ion channels are mainly found in the ___ segment of a neuron
receptive
A return of the membrane potential towards the resting membrane potential immediately following depolarization is called _____. depolarization Repolarization Summation
repolarization
______ is the return of polarity from positive back to negative (the RMP). Summation Depolarization Depolarization
repolarization
The function of a neuron is dependent on ___ Resting membrane potentials changing Resting membrane potentials staying the same
resting membrane potentials changing
Na+ and K+ leak channels and Na+/K+ pumps on the neuron are responsible for establishing and maintaining the ____ membrane ____.
resting potential
Removal of neurotransmitters from the synaptic cleft by transport into the synaptic knob is known as Diffusion Reuptake Degradation
reuptake
A mixed nerve is one that contains both
sensory and motor neurons
The portion of the nervous system that conducts impulses from the skin, joints, skeletal muscles, and special senses is the ___ division
somatic sensory
A damaged axon within the PNS can regenerate if ______. Part of the cell body remains Some Neurilemma remains Some dendrocytes remain Some oligodendrocytes
some neurilemma remains
When threshold is reached, depolarization occurs with the same amplitude of potential change. This is known as Cable properties of axons Saltatory conduction A graded response The all or none principle
the all or none principle
If all the sodium leakage channels were removed from the cell membrane of a neuron, The membrane potential would become more positive. The membrane potential would be about -90 mV. Intracellular sodium levels would increase. Sodium would diffuse out of the neuron.
the membrane potential would be about -90 millivolts.
As a neuron's refractory period ends, its sodium channels are changing from
their inactivated state to their resting state.
In retrograde transport, substances are moved ___ the cell body
toward
Vesicles involved in retrograde transport are moving ______ the cell body. Away from Toward Toward and away from
toward
A graded potential is one that
varies in size depending on the magnitude of the stimulus (larger voltage change for stronger stimulus).
The measure of the difference in electrical charge between two areas is called a ___
voltage
The type of voltage-gated channel that possesses an inactivation gate that temporarily closes after the channel is active is the
voltage gated sodium channel
If a subthreshold value is reached on an axon membrane, an action potential ______. Will not occur Will occur
will not occur
