Nervous System
When a sensory neuron is excited by some form of energy, the resulting graded potential is called a(n) ________. A.postsynaptic potential B.excitatory potential C.action potential D.generator potential
Generator potential
An action potential is regarded as an example of a positive feedback. Which of the following examples below best illustrates the positive feedback aspect of an action potential? A threshold stimulus will cause the opening of voltage gated sodium ion channels that will cause further depolarizing stimulus. This stimulus will open still more voltage gated sodium ion channels. Voltage gated potassium ion channels open slowly and remain open long enough to cause hyperpolarization. Potassium permeability is about 25 times greater than sodium ions. The sodium potassium pump consistently moves ions as long as ATP is available, and regardless of membrane potential changes.
A threshold stimulus will cause the opening of voltage gated sodium ion channels that will cause further depolarizing stimulus. This stimulus will open still more voltage gated sodium ion channels
Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane? Specific sodium gates will open. Sodium gates will open first, then close as potassium gates open. Specific potassium gates will open. A single type of channel will open, permitting simultaneous flow of sodium and potassium.
A single type of channel will open, permitting simultaneous flow of sodium and potassium.
Which of the following is true about the movement of ions across excitable living membranes? Ions always move passively across membranes. Ions always move actively across membranes through leakage channels. Ions always move from an area of higher concentration to an area of lower concentration. Sodium gates in the membrane can open in response to electrical potential changes.
Sodium gates in the membrane can open in response to electrical potential changes.
The depolarization phase of an action potential is punctuated by the closing of inactivation gates in the voltage gated sodium ion channels. All of the following are consequences of this inactivation except one. Choose the statement below that is not a consequence of the closing of inactivating gates. This allows for the one way transmission of action potential down the axon. This limits the frequency of action potentials down the axon. This stops the depolarization of the axon membrane. This allows for the efflux (diffusion out) of potassium ions, resulting in the repolarization of the cell
This allows for the efflux (diffusion out) of potassium ions, resulting in the repolarization of the cell.
When a neurotransmitter like acetylcholine is acting in an excitatory manner which of the following is likely a result of the acetylcholine acting on the post synaptic cell? Chemically gated potassium channels will open. Chemically gated chloride channels will open. Chemically gated sodium channels will be closed. Chemically gated sodium channels will open.
chemically gated sodium channels will open
Which of the following neurotransmitters inhibits pain and is mimicked by morphine, heroin, and methadone? nitric oxide endorphin serotonin acetylcholine
endorphin
These cells in the CNS have cilia that move in order to circulate cerebrospinal fluid ________. oligodendrocytes Schwann cells astrocytes ependymal cells
ependymal cells
Collections of nerve cell bodies outside the central nervous system are called ________. nerves nuclei ganglia tracts
ganglia
An inhibitory postsynaptic potential (IPSP) is associated with ________. opening of voltage-regulated channels hyperpolarization a change in sodium ion permeability lowering the threshold for an action potential to occur
hyperpolarization
When a neurotransmitter like GABA is acting in an inhibitory manner which of the following is likely a result of the GABA acting on the post synaptic cell? influx of positively charged ions into the postsynaptic cell opening of chemically gated sodium channels hyperpolarization of the postsynaptic cell membrane depolarization of the postsynaptic cell membrane
hyperpolarization of the postsynaptic cell membrane
Which of the following correctly describes a graded potential? it can have amplitudes of various sizes it travels long distances it has a depolarization, repolarization and hyperpolarization phase it is initiated by voltage changes in the membrane
it can have amplitudes of various sizes
The interior surface of a neuron's plasma membrane at resting membrane potential will have a ________. negative charge and contains less sodium than outside of the cell negative charge and contains more sodium than outside of the cell positive charge and contains more sodium than outside of the cell positive charge and contains less sodium than outside of the cell
negative charge and contains less sodium than outside of the cell
If a post synaptic neuron is stimulated to threshold by spatial summation this implies that ________. the post synaptic cell has many voltage gated ion channels the post synaptic cell is slow to repolarize the postsynaptic cells has many synapses with many presynaptic neurons the post synaptic cell has a lower than normal threshold
the post synaptic cells have many synapses with many presynaptic neurons
Which of the following is false or incorrect? An excitatory postsynaptic potential occurs if the excitatory effect is greater than the inhibitory effect but less than threshold. An inhibitory postsynaptic potential occurs if the inhibitory effect is greater than the excitatory, causing hyperpolarization of the membrane. A nerve impulse occurs if the excitatory and inhibitory effects are equal.
A nerve impulse occurs if the excitatory and inhibitory effects are equal.
If a post synaptic cell is stimulated to threshold by temporal summation this implies that ________. the postsynaptic cell can be influenced by only one presynaptic cell the presynaptic neuron is sending frequent IPSP a presynaptic neuron is sending frequent EPSP the postsynaptic cell is sending frequent action potential
a presynaptic neuron is sending frequent esps
Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle? norepinephrine acetylcholine gamma aminobutyric acid cholinesterase
acetylcholine
Bacteria in the blood can be prevented entry to the fluids surrounding the brain. Which cells are most responsible for preventing bacteria from entering the fluids of the brain? satellite cells astrocytes Schwann cells oligodendrocytes
astrocytes
The concentration neurotransmitters in the fluid of the synaptic cleft must be tightly regulated for neurons to function properly. Which of the following cells is most responsible for aiding in this regulation? A) satellite cells B) astrocytes C) Schwann cells D) oligodendrocytes
astrocytes
Like all cells, the neurons' internal organization dictates its function. Neurons have relatively many mitochondria, an extensive network of rough endoplasmic reticulum and many clusters of ribosomes. These cellular features indicate all of the following EXCEPT ________. neurons have a relatively high consumption of oxygen neurons must meet a high demand for ATP neurons produce many proteins neurons have stable, relatively unchanging internal environments
neurons have stable, relatively unchanging internal environments
Which of the following is not a chemical class of neurotransmitters? nucleic acid amino acid ATP and other purines biogenic amine
nucleic Acid
Schwann cells are functionally similar to ________. astrocytes ependymal cells microglia oligodendrocytes
oligodendrocytes
Nerve impulses leading to the brain carry information about cool temperatures on the skin. The nerve fibers sending these signals will most likely belong to which division of the nervous system? sensory (afferent) division somatic nervous system sympathetic division parasympathetic division
sensory (afferent) division
Which of the following describes the excitatory postsynaptic potential? moves membrane potential away from threshold short distance depolarization short distance hyperpolarization opens K+ or Cl- channels
short distance depolarization
During the relative refractory period of an action potential, a larger than normal stimulus is needed to cause another action potential. This is due to the fact that ________. the inactivation gates on voltage gated sodium ion channels are closed the voltage gated potassium ion channels remain open long enough to hyperpolarize the axon membrane the membrane is now impermeable to all ions the sodium potassium pump will stop working during relative refractory
the voltage gated potassium ion channels remain open long enough to hyperpolarize the axon membrane
Immediately after an action potential has peaked, which of the following channels will open? chemically gated chloride channels voltage gated potassium channels voltage gated sodium channels voltage gated calcium channels
voltage gated potassium channels
