Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Kim Ferguson
Physiology Week 7
| Question | Answer |
|---|---|
| Neurons are the only living cells that maintain a difference in the concentration of ions across their membranes. | False |
| In depolarization the membrane potential moves toward zero, whereas in hyperpolarization the membrane potential moves away from zero. | True |
| The difference in electrical charge between the inside and outside of a membrane is called the membrane potential. | True |
| Movement of the membrane potential away from zero (below the usual RMP) is called | hyperpolarization. |
| If the magnitude of the local depolarization surpasses a limit called the _____, voltage-gated Na+ channels are stimulated to open. | threshold potential |
| The speed of a nerve impulse depends on the neuron’s resting potential. | False |
| A membrane that exhibits a membrane potential is said to be | polarized. |
| The membrane potential maintained by a nonconducting neuron’s plasma membrane is called the _____ membrane potential. | resting |
| When a neuron is resting, the inner surface of its plasma membrane is slightly positive compared with its outer surface. | False |
| If the threshold potential is surpassed, the full peak of the action potential is always reached. | True |
| The brief period during which a local area of an axon's membrane resists re-stimulation is called the __________ period. | refractory |
| A term commonly used as a synonym for action potential is | nerve impulse. |
| The sodium-potassium pump actively pumps three potassium ions out of the neuron and two sodium ions into the neuron. | False |
| The active transport mechanism in the plasma membrane that transports sodium and potassium ions in opposite directions and at different rates is the | sodium-potassium pump. |
| When neurotransmitters from synaptic knobs stimulate a postsynaptic neuron in rapid succession, their effect can add up over a brief period to produce an action potential. This is called | temporal summation. |
| An ion channel that opens in response to a sensory stimulus is a(n) | stimulus-gated channel. |
| What mechanism quickly terminates the action of a neurotransmitter once it binds to its postsynaptic receptor? | Neurotransmitter molecules are metabolized into inactive compounds. Neurotransmitter molecules are transported into nearby glial cells. Neurotransmitter molecules are transported back into synaptic knobs. All of these are correct. |
| Which chemicals allow neurons to communicate with one another? | neurotransmitters |
| The tiny bulge at the end of a terminal branch of a presynaptic neuron’s axon is called a(n) | synaptic knob. |
| A neurologist is using a voltmeter to measure potential. The membrane potential of a neuron was recorded at +30 mV. This is what type of membrane potential? | Action |
| The action potential seems to “leap” from node to node along a myelinated fiber. This type of impulse regeneration is called __________ conduction. | saltatory |
| A synapse can occur only between an axon and: | any of the above. |
| The mechanisms that produce and maintain the resting membrane potential do so by producing a | slight excess of positive ions on the outer surface of the plasma membrane. |
| Which membrane receptor acts to directly change ion permeability when stimulated? | Gated-channel receptor |
| In a myelinated neuron, the impulse can travel under the myelin between nodes of Ranvier. | True |
| The difference between sodium and potassium in the generation of action potential is that: | sodium causes depolarization of the cell membrane, and potassium causes repolarization of the cell membrane. |
| The magnitude of the action potential peaks when the sodium channels close. | True |
| Whether an impulse is continued through the neuron depends on the magnitude of the voltage in the axon hillock. | True |
| In a myelinated fiber, the action potential jumps from one node of Ranvier to the next. | True |
| There are two types of synapses—the electrical synapse and the __________ synapse. | chemical |
| For a neurotransmitter to produce an inhibitory postsynaptic potential, which of the following channels must open? | Potassium and/or chloride channels |
| Compared with the outside of the neuron, the inside has a(n) ____ charge. | negative |
| During a relative refractory period: | the action potential can be initiated with a strong stimulus. |
| The fastest nerve fibers in the body can conduct an impulse that is how much faster than the slowest fibers in the body? | Almost 300 times faster |
| Which is true of a neuron with a resting potential? | The sodium pump has moved Na+ to the outside of the plasma membrane. |
| Which of the following antidepressants acts by blocking the action of monoamine oxidase (MAO)? | Phenelzine |
| Neurotransmitters are released in a synapse and bind to: | receptors on the postsynaptic neuron. |
| Which of the following is not one of the main chemical classes of neurotransmitters? | Triglycerides |
| A synaptic knob would be located on a(n): | axon. |
| The fastest nerve fibers in the body can conduct impulses up to approximately _____ meters per second. | 130 |
| When current leaps across an insulating myelin sheath from node to node, the type of impulse conduction is called: | saltatory conduction. |
| Stimulus-gated channels open in response to: | sensory stimuli. |
| When an impulse reaches a synapse: | chemical transmitters are released. |
| Within the nervous system, coding for the strength of a stimulus is accomplished through: | the frequency of nerve impulses. |
| Which is true of an action potential? | The outside of the plasma membrane is negatively charged, and the inside is positively charged. |
| Serotonin is an example of a(n): | amine neurotransmitter. |
| Excitatory neurotransmitters are most likely to: | initiate an action potential. |
| Severe depression can be caused by a deficit in certain brain synapses of: | amines. |
| A synapse consists of: | a synaptic knob. a synaptic cleft. the plasma membrane of a postsynaptic neuron. all of the above. |
| The neurotransmitter(s) that inhibit(s) the conduction of pain impulses is(are): | enkephalins. |
| Which of the following statements about amino acid neurotransmitters is incorrect? | They are all inhibitory neurotransmitters. |
| Acetylcholine is in the same class of neurotransmitters as: | serotonin. histamine. dopamine. none of the above. |
| Which of the following is true of spatial summation? | Neurotransmitters released simultaneously from several presynaptic knobs converge on one postsynaptic neuron. |
| Dopamine, epinephrine, and norepinephrine are classified as: | catecholamines. |
| Which of the following is not used by the body as a neurotransmitter? | Nitric oxide Acetylcholine Carbon monoxide All of the above are used by the body as neurotransmitters. |
| Which neuron could transmit a nerve impulse the fastest? | A large-diameter neuron with myelin |
| The first event to occur when an adequate stimulus is applied to a neuron is: | some of the sodium channels at the point of stimulation open. |
| A slight shift away from the resting membrane potentials in a specific region of the plasma membrane is called a _____ potential. | local |
| No impulse can be sent through a neuron: | during the absolute refractory period. |
| The only ion(s) that can diffuse across a neuron’s membrane when the neuron is at rest is (are): | potassium. |
Created by:
Kferguson76
Popular Physiology sets