Nervous System, Neurons, and Neurotransmitters Flashcards
A drug that has the same effects as a neurotransmitter or that increases the effects of a neurotransmitter is referred to as a(n):
A. antagonist.
B. inverse agonist.
C. partial agonist.
D. agonist.
Answer D is correct. Agonists mimic or increase the effects of a neurotransmitter.
________ is a major inhibitory neurotransmitter in the brain, and low levels have been linked to chronic insomnia and anxiety disorders.
A. Dopamine
B. Acetylcholine
C. GABA
D. Glutamate
Answer C is correct. Low levels of GABA have been linked to insomnia, seizures, and anxiety, and benzodiazepines reduce anxiety and induce sleep by amplifying its effects.
The primary function of the myelin sheath is to:
A. increase the speed of nerve impulses.
B. increase the size of the action potential.
C. facilitate synaptic transmission.
D. facilitate neurogenesis.
Answer A is correct. The myelin sheath is a fatty substance that insulates and increases the speed of nerve impulses in the axons of neurons.
The somatic nervous system conveys information from the sense organs to the central nervous system and from the central nervous system to:
A. the skeletal muscles.
B. the smooth muscles.
C. the skeletal and smooth muscles.
D. neither the skeletal nor the smooth muscles.
Answer A is correct. The somatic nervous system innervates the skeletal muscles, while the autonomic nervous system innervates the smooth muscles, cardiac muscle, and glands.
Memory loss during the initial stage of Alzheimer’s disease has been most consistently linked to low levels of __________ in the entorhinal cortex and hippocampus.
A. dopamine
B. norepinephrine
C. acetylcholine
D. GABA
Answer C is correct. The research suggests that the degeneration of acetylcholine receptors in the entorhinal cortex and hippocampus is responsible for the early memory loss associated with Alzheimer’s disease.
A drug that increases which of the following is likely to be most effective as a treatment for obsessive-compulsive disorder?
A. serotonin
B. acetylcholine
C. norepinephrine
D. GABA
Answer A is correct. Knowing that SSRIs (selective serotonin reuptake inhibitors) are prescribed for obsessive-compulsive disorder (OCD) would have helped you identify the correct answer to this question. Note that, while OCD has been most consistently linked to low levels of serotonin, there’s also research linking it to abnormal levels of dopamine and glutamate.
Which of the following is the most important reward pathway in the brain and the key pathway in substance abuse?
A. mesocortical dopaminergic pathway
B. mesolimbic dopaminergic pathway
C. nigrostriatal dopaminergic pathway
D. tuberoinfundibular dopaminergic pathway
Answer B is correct. The mesolimbic dopaminergic pathway is an essential part of the brain’s “reward circuit” and plays a role in the reinforcing effects of cocaine, amphetamines, nicotine, alcohol, opiates, and other substances of abuse.
Stimulus intensity is encoded by:
A. the intensity of action potentials.
B. the frequency of action potentials.
C. the intensity and frequency of action potentials.
D. neither the intensity nor the frequency of action potentials.
Answer B is correct. Action potentials are all-or-none responses which means they either occur or don’t occur and, when they occur, they have the same intensity. Consequently, stimulus intensity is not determined by the intensity of an action potential but by the frequency of the action potentials generated by a neuron and/or by the number of neurons that generate action potentials.
