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ch.12 practice questions

Terms in this set (45)

After birth Schwanncells
increase their presence and amount of myelination in the peripheral nervous system
The motor portion of the autonomic nervous system can be divided into
sympathetic and parasympathetic divisions.
What specific type of unipolar neuron detects a sharp pain?
nocicceptor
An excitatory neurotransmitter ______ the postsynaptic membrane.
depolarizes
In an action potential, the electric current that flows is generated by the movement of ______ across the membrane.
ions
Faster communication and synchronization are two advantages of
electrical synapses
Which of these allows more potassium to exit the neuron and helps in maintaining the resting membrane potential?
leak channel
These statements describe what part of an action potential?
• Sodium activation gates are closed • Sodium inactivation gates are open • Potassium gates are open • Repolarization is occurring
Relative refractory period
Hearing your cell phone ring in an quiet lecture hall is an example of which nervous system functions?
sensory function
Na+/K+-ATPase is considered to be an electrogenic pump because
it contributes to the negativity of the resting membrane potential.
Which is a function of the nervous system? Select all that apply.
-sensory function
-integrative function
-motor function
Which of the following types of neurons is the most common type of neuron found in the brain and spinal cord?
multipolar neuron
During the resting state of a voltage-gated Na+ channel,
1. the inactivation gate is open. 2. the activation gate is closed. 3. the channel is permeable to Na+.
both 1 and 2 are true
What events must occur for the creation of an action potential? Select all that apply.
-Summation of depolarizing graded potential.
-Threshold at the trigger zone.
Saltatory conduction is described by which statements?
1) current passes through the entire unmyelinated axon membrane 2) current passes through a myelinated axon only at the nodes of Ranvier 3) current occurs at faster rates 4) voltage-gated channels are concentrated in unmyelinated regions 5) More energy is used to increase speed of conduction
2,3,4
All of the following statements are true for which type of cell?
• has a charge imbalance across its membrane. • includes most cells of the body.• exhibits a membrane potential. inside is more negative relative to outside.
polarized cell
Which neurotransmitters are used in virtually all of the inhibitory synapses found in the spinal cord?
gamma aminobutyric acid (GABA) and glycine
Electrical excitability is seen in which cell? Select all that apply.
-muscle cells
-neurons
Which ion channelsare used in the production of electrical signals in neurons? Select all that apply
-Leak channel
-Voltage-gated channel
-Ligand-gated channel
-Mechanically gated channel
Diffusion, enzymatic degradation, and uptake by cells are all ways to
remove a neurotransmitter
During an action potential's ___________, a second stimulus can be produced only if the stimulus is greater than the threshold stimulus. This event corresponds to the period when the __________ remain open and sodium inactivation gates have reopened.
relative refractory period; potassium voltage-gated channels
Which electrical signal can allow for rapid long-distance communication within the nervous system?
nerve action potential
Manic-depressive illness is associated with
bipolar disorder
Wallerian degeneration refers to
degeneration of the distal end of axon and myelin sheath after neural injury.
Which type of central nervous system tissue contains neuronal cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglial cells?
gray matter
Acetylcholine is _________ at the neuromuscular junctions and ________ at cardiac muscle in the parasympathetic pathway.
excitatory; inhibitory
With respect to neurons, the term "nerve fiber" refers to what structure? Select all that apply.
-an axon
-a dendrite
is a neurotransmitter that is made on demand and can be used for microbial defense. ______ is a neurotransmitter that is made on demand and is used for vasodilation and special sensory recognition.
nitric oxide; carbon monoxide
This type of neuron has one dendrite and one axon emerging from the cell body.
bipolar neuron
A depolarizing graded potential
makes the membrane less polarized
When a graded potential summates to threshold at the axon hillock,
voltage-gated Na+ channels open rapidly.
Which organelle is a common site of protein synthesis in neurons?
nissl body
This type of neural circuit consists of a single presynaptic neuron synapsing with several postsynaptic neurons.
Diverging circuit
In temporal summation, a single presynaptic neuron stimulates the creation of action potentials in a postsynaptic neuron when it
fires at a fast enough rate that the sum of EPSPs in the postsynaptic neuron moves above threshold.
Which of the following types of neurons is exclusively found in the cerebellum?
PURKINJE CELLS
Which types of membrane channels can cause an IPSP on a neuron when acetylcholine binds to the receptor? Select all that apply.
-ionotropic ligand-gated channels
-metabotropic ligand-gated channels
In the process of spatial summation, _____ are added together and _____ are subtracted from that total to determine whether _____ will be created at the trigger zone of the postsynaptic neuron.
EPSPs; IPSPs; action potentials
open and close in response to physical deformation of receptors.
mechanically gated channels
Which of the neurons is located deep in the dermis or hypodermis and detect deep pressure?
pacinian Corpuscle
Chromatolysis refers to
break up of Nissl bodies after neural injury.
Plasticity means the ability to
change based on experience
The nervous system can distinguish between a light touch and a heavier touch because
the frequency of impulses sent to sensory centers is changing.
Which division of the peripheral nervous system only innervates the gastrointestinal tract's wall?
enteric nervous system
A postsynaptic neuron responds to acetylcholine neurotransmitter by creating
either EPSP or IPSP
During an action potential's ___________, a second stimulus will not produce a second action potential (no matter how strong that stimulus is). This event corresponds to the period when the __________ remain open and the sodium inactivation gates have not reopened.
absolute refractory period; voltage-gated potassium channels
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