Which of the choices below describes the ANS?
sensory neurons that convey information from somatic receptors in the head, body wall, and limbs and from receptors from the special senses of vision, hearing, taste, and smell to the CNS
motor fibers that conduct nerve impulses from the CNS to skeletal muscles
motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands
sensory and motor neurons that supply the digestive tract
motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands
Which of the following is NOT a difference between graded potentials and action potentials?
Graded potentials can result from the opening of chemically gated channels; action potentials require the opening of voltage-gated channels.
Graded potentials occur along dendrites, whereas action potentials occur along axons.
Spatial summation is used to increase the amplitude of a graded potential; temporal summation is used to increase the amplitude of an action potential.
Greater stimulus intensity results in larger graded potentials, but not larger action potentials.
Spatial summation is used to increase the amplitude of a graded potential; temporal summation is used to increase the amplitude of an action potential.
When calcium ions enter the synaptic terminal,
When calcium ions enter the synaptic terminal,
the inside of the receiving neuron becomes more negative.
the inside of the receiving neuron becomes more positive.
neurotransmitter molecules are quickly removed from the synaptic cleft.
they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron.
they cause an action potential in the sending neuron.
they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron.
Which of the following is not a function of astrocytes?
guide the migration of young neurons, synapse formation, and helping to determine capillary permeability
support and brace neurons
anchor neurons to blood vessels
control the chemical environment around neurons
provide the defense for the CNS
provide the defense for the CNS
In what way does the interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external environment? The interior is ________.
positively charged and contains less sodium
positively charged and contains more sodium
negatively charged and contains less sodium
negatively charged and contains
more sodium
negatively charged and contains less sodium
Strong stimuli cause the amplitude of action potentials generated to increase.
True
False
False
The generation of an action potential in a neuron requires the presence what type of membrane channels?
leakage channels
voltage-gated channels
chemically gated channels
membrane channels are not required
voltage-gated channels
Which of the following describes the excitatory postsynaptic potential?
short distance hyper polarization
opens K+ or Cl- channels
moves membrane potential away from threshold
short distance depolarization
short distance depolarization
Which of the following is not true of graded potentials?
They are short-lived.
They increase amplitude as they move away from the stimulus point.
They can be called postsynaptic potentials.
They can form on receptor endings.
They increase amplitude as they move away from the stimulus point
Which of the following neurotransmitters inhibits pain and is mimicked by morphine, heroin, and methadone?
nitric oxide
acetylcholine
endorphin
serotonin
endorphin
Which membrane potential occurs because of the influx of Na+ through chemically gated channels in the receptive region of a neuron?
excitatory postsynaptic potential
inhibitory action potential
inhibitory postsynaptic potential
action potential
excitatory postsynaptic potential
Which neuron circuit pattern is involved in the control of rhythmic activities such as breathing?
parallel after-discharge circuit
diverging circuit
converging circuit
reverberating circuit
reverberating circuit
What are the differences between graded potentials and action potentials?
Which of the following is not a difference between graded potentials and action potentials quizlet?
What are two major differences between graded and action potentials?
Graded potentials | Action potentials |
Amplitude is proportional to the strength of the stimulus. | Amplitude is all-or-none; strength of the stimulus is coded in the frequency of all-or-none action potentials generated. |
Amplitude is generally small (a few mV to tens of mV). | Large amplitude of ~100 mV. |