Biopsych 1 neurons,synapses, esps, isps, drugs, brain, funtions,chemical events, neurotransmitter. lfbella published on April 19, 20112447 responses 3 4.6★ / 5 Questions in vertical order Most neurons have a spontaneous firing rate, a periodic production of action potentials even without synaptic input. true false Specialized junctions between neurons are called: nodes of Ranvier. spines. dendrites. synapses. The proper order of a reflex arc is: motor neuron, sensory neuron, interneuron. sensory neuron, motor neuron, interneuron. motor neuron, interneuron, sensory neuron. sensory neuron, interneuron, motor neuron. Sherrington deduced that transmission at a synapse must be slower than conduction along an axon. This was based on what kind of evidence? temporal summation drugs that increase or inhibit activity at synapses the speed of reflexive responses differences in diameter between axons and dendrites Sherrington found that repeated stimuli within a brief time have a cumulative effect. He referred to this phenomenon as: temporal summation spatial summation synaptic summation saltatory summation The primary difference between an EPSP and an action potential is that the magnitude of an action potential decreases as it travels along the membrane. EPSPs occur without sodium ions entering the cell. action potentials are always hyperpolarizations. EPSPs are subthreshold events that decay over time and space. Depolarization is to ____ as hyperpolarization is to ____. excitation; inhibition inhibition; excitation increasing the threshold; decreasing the threshold decreasing the threshold; increasing the threshold Spatial summation refers to: multiple weak stimulations that occur in rapid succession. a decrease in responsiveness after repeated stimulation. multiple weak stimulations that occur at the same time. an increase in the strength of action potentials after repeated stimulation. Which of the following patterns of post-synaptic excitation will most likely result in an action potential? rapid sequence of EPSPs rapid sequence of IPSPs large number of simultaneous IPSPs large number of simultaneous IPSPs and EPSPs A normal, healthy animal never contracts the flexor muscles and the extensor muscles of the same leg at the same time. Why not? When the interneuron sends excitatory messages to one, inhibitory messages go to the other. They are mechanically connected in a way that makes it impossible for both to contract at the same time. Such coordination is learned through prenatal movement. Both muscles are controlled by branches of the same axon. Which of the following would most likely result in an IPSP? potassium ions entering the cell sodium ions entering the cell chloride ions entering the cell chloride ions leaving the cell An EPSP is to ____ as an IPSP is to ____. hyperpolarization; depolarization depolarization; hyperpolarization spatial summation; temporal summation temporal summation; spatial summation After one frog's heart has been stimulated, an extract of fluid from that heart can make a second frog's heart beat faster. What conclusion did Otto Loewi draw from these results? Transmission at synapses is a chemical event. The sympathetic and parasympathetic nervous systems are antagonistic. Transmission at heart muscle synapses is electrical. Hormones facilitate the actions of the nervous system. The correct sequence of chemical events at a synapse is: reuptake, release, transport, synthesis synthesis, transport, release, reuptake transport, release, reuptake, synthesis recycle, reuse, release, return In addition to influencing other neurons, ____ dilates the nearby blood vessels, thereby increasing blood flow to that area of the brain. endorphins glycine nitric oxide Acetylcholine What provides the building blocks for synthesizing all neurotransmitters? substances found in the diet breakdown products of DNA breakdown products formed from other transmitters methane and ethanol The catecholamines include: epinephrine, norepinephrine, dopamine, serotonin. epinephrine, serotonin, dopamine. dopamine, serotonin, acetylcholine. epinephrine, norepinephrine, dopamine. If you eat a food containing tryptophan, what can you consume with it to increase its entry to the brain? phenylalanine carbohydrates fats Thiamine Neurotransmitter filled packets in the presynaptic neuron are called? sacs. bags. vesicles. terminals. The release of neurotransmitter from the presynaptic terminal is most dependent on the influx of what ion? sodium potassium chloride Calcium Exocytosis is the process by which neurotransmitters are: excreted into the synaptic cleft. synthesized. destroyed. secreted into synaptic vesicles. What is the synaptic cleft? the gap between the presynaptic neuron and the postsynaptic neuron a packet that stores neurotransmitter molecules a subthreshold depolarization the storage location for calcium ions In general, a single neuron releases ____ neurotransmitter(s), and can respond to ____ neurotransmitter(s). one; many dozens of; only one several; only one several; many What determines the effect that a neurotransmitter has on the postsynaptic neuron? the speed the action potential traveled down the axon the number of branches of the presynaptic axon the receptors on the postsynaptic membrane the distance between the synapse and the cell body What does it mean to say that acetylcholine exerts ionotropic effects? It opens gates for a particular ion. It alters the permeability of the presynaptic neuron. It increases the concentration of ions within the vesicles. It changes the electrical charge of sodium ions from positive to negative. Receptor molecules for neurotransmitters that exert metabotropic effects are proteins that bind to ____ outside the membrane, and attach to ____ inside the membrane. calcium; potassium neurotransmitters; nicotine neurotransmitters; G-proteins adenosine; nitric oxide A hormone is a chemical that is: secreted by a gland to the outside world. conveyed by the blood to other organs, whose activity it influences. capable of activating or inhibiting muscle fibers. a feedback message from the postsynaptic neuron to the presynaptic neuron. The anterior pituitary is composed of ____, and the posterior pituitary is composed of ____. glandular tissue, neural tissue neural tissue, glandular tissue neural tissue, neural tissue glandular tissue, glandular tissue What would be the effect of a drug that inhibits the action of the enzyme acetylcholinesterase? prolonged action of acetylcholine at its synapses decreased duration of action of acetylcholine at its synapses decreased synthesis of acetylcholine by the presynaptic cell increased synthesis of acetylcholine by the presynaptic cell After serotonin or one of the catecholamine transmitters stimulates the postsynaptic receptor, most of the transmitter molecules: remain on the receptor until other neurotransmitters replace them. are broken into components while still attached to the postsynaptic cell. are metabolized by the postsynaptic cell as a source of energy. are reabsorbed by the presynaptic cell. "Transporter" proteins transport neurotransmitters: back into the presynaptic neuron. across the synapse to the postsynaptic neuron. across the synapse back to the presynaptic neuron. to the appropriate receptor sites. COMT and MAO are: enzymes that convert catecholamines into inactive chemicals. enzymes that make catecholamines. neurotransmitters in the same group as serotonin. the inactive fragments of catecholamines. Activation of autoreceptors tends to: increase further neurotransmitter release. stimulate GABA release. increase sodium-potassium pump activity. decrease further neurotransmitter release. A drug that blocks the effects of a neurotransmitter is a(n) ____; a drug that mimics or increases the effects is a(n) ____. neuromodulator; synergist agonist; antagonist depressant; stimulant antagonist; agonist Which effect would be considered to be antagonistic? blocking the synthesis of neurotransmitters stimulating the release of neurotransmitters blocking the reuptake of neurotransmitters interfering with the breakdown of neurotransmitters Which effect would be considered to be agonistic? blocking the synthesis of neurotransmitters stimulating the release of neurotransmitters blocking the postsynaptic receptors mimicking enzymes that breakdown neurotransmitters If a drug binds to a particular receptor, it is said to: increase the synthesis of the neurotransmitter used at that receptor. decrease the synthesis of the neurotransmitter used at that receptor. stimulate breakdown at that receptor. have an affinity for that type of receptor. With respect to drug effects, "efficacy" means the tendency of a drug to: have inhibitory effects. have excitatory effects. attach to a receptor. activate a receptor. If a drug has high affinity and high efficacy, what effect does it have on the postsynaptic neuron? antagonistic agonistic proactive Destructive The brain area most often linked to drug addiction is the: nucleus accumbens. whole limbic system. frontal lobes. brain stem. Most habit-forming drugs activate which type of synapse? acetylcholine opiate GABA Dopamine Why do cocaine and amphetamine produce similar effects? Both increase the activity of the sodium-potassium pump. Both increase the presence of dopamine in the synapses. Both cause a weakening of the blood-brain barrier. The brain converts both of them into acetylcholine. Methylenedioxymethamphetamine (MDMA) is also known as? ecstasy crack angel dust Ganja Opiate drugs bind to receptors in the brain for: endorphins. catecholamines. indolamines. monoamines. A certain drug user experiences intensified sensations and the illusion that time is passing slowly. He also experiences problems with attention and memory. These symptoms are most characteristic of the use of which drug? LSD cocaine nicotine Marijuana Anandamide and 2-AG are believed to be the naturally occurring neurotransmitters that bind to the same receptors as which drug? heroin cocaine alcohol Marijuana LSD and other hallucinogenic drugs resemble which neurotransmitter? norepinephrine dopamine serotonin Acetylcholine What are the two parts of the central nervous system? autonomic nervous system and somatic nervous system cerebrum and cerebellum sympathetic division and parasympathetic division brain and spinal cord Together, the somatic nervous system and the autonomic nervous system make up the ____ nervous system. peripheral central sympathetic Dorsal When someone tickles you, the tickling sensation will be carried by neurons that are part of the ____ nervous system. central parasympathetic somatic Autonomic An axon in your hand causes contraction of a muscle fiber in your finger as you write. This neuron belongs to which branch of the nervous system? central somatic sympathetic Parasympathetic The basal ganglia are a related cluster of cell bodies in the central nervous system. Technically, the basal ganglia should have been name the basal: tract. lamina. gyrus. nuclei. The cell bodies of sensory neurons that are in clusters of neurons outside the spinal cord are called? sensory nuclei sensory clusters ventral root ganglia dorsal root ganglia According to the Bell-Magendie law: ventral roots of the spinal cord carry sensory information. dorsal roots of the spinal cord carry motor information. ventral and dorsal roots both carry sensory and motor information. ventral roots carry motor information while dorsal roots carry sensory information. In the spinal cord, white matter is comprised mostly of ____, while gray matter is mostly ____. cell bodies, myelinated axons dendrites, myelinated axons myelinated axons, cell bodies cell bodies, dendrites You are walking after dark. A sudden noise frightens you. Your heart pounds, your pulse races, and your breathing rate increases. These responses are due to your: parasympathetic nervous system. sympathetic nervous system. somatic nervous system. immune system. Digestive activity is increased by the activation of which branch of the autonomic nervous system? the parasympathetic the sympathetic both the parasympathetic and sympathetic neither the parasympathetic nor the sympathetic Sympathetic is to ____ as parasympathetic is to ____. serotonin; dopamine dopamine; serotonin acetylcholine; norepinephrine norepinephrine; acetylcholine The hindbrain consists of the: tectum, tegmentum, and reticular formation. thalamus and hypothalamus. spinal cord and cranial nerves. medulla, pons, and cerebellum. Breathing, heart rate, vomiting, salivation, coughing, and sneezing are all controlled by which structure? medulla thalamus cerebellum Pons The raphe system ______ the brain's readiness to respond to stimuli, and sends axons to the ______. increases; cerebellum decreases; forebrain decreases; basal ganglia increases; forebrain Besides problems with balance and coordination, a person with damage to the cerebellum would also likely have problems with: reflexive changes in heart rate. shifting attention between auditory and visual stimuli. amnesia. rational decision-making. Superior colliculus is to _____ as inferior colliculus is to _____. vision; hearing taste; smell vision; touch touch; hearing A group of forebrain structures is important for motivated and emotional behavior. What is the name given to this group of structures? limbic system reticular formation tegmentum basal ganglia One function of the thalamus is to: relay sensory information to the cerebral cortex. regulate sleep cycles. direct the secretions of the hypothalamus. moderate emotional outbursts. Sensory information which is not processed by the thalamus includes: olfactory information. visual information. auditory information. somatosensory information. An impairment of eating, drinking, temperature regulation, or sexual behavior suggests possible damage to which brain structure? midbrain hippocampus hypothalamus Cerebellum Damage to the basal ganglia would most likely result in: a movement disorder. problems with visual perception. problems with auditory perception. a loss of pain sensation. An individual has difficulty remembering certain things after brain damage, but all memories stored before the damage are intact. The brain area most likely damaged is the: fornix. hypothalamus. hippocampus. nucleus basalis. What is contained in the ventricles of the brain? glia cell bodies dendrites and axons cerebrospinal fluid Membranes that surround the brain and spinal cord are called: CSF. ventricles. meninges. hydrocephali. A function of the cerebrospinal fluid is to: cushion the brain. hold blood in reserve for emergencies. maintain the blood-brain barrier. synthesize neurotransmitters. Each hemisphere of the cerebral cortex receives most of its input from the ____ side of the body and controls the muscles on the ____ side. contralateral; ipsilateral ipsilateral; contralateral ipsilateral; ipsilateral contralateral; contralateral The ______ constitutes a higher percentage of the brain in primates than in other species of comparable size. cerebral cortex. cerebellum basal ganglia thalamus. What deficits does a person suffer after damage to the striate cortex in the occipital lobe? deafness blindness loss of touch and other body sensations loss of fine motor control The postcentral gyrus in the parietal lobe is the primary area for which type of sensation? touch vision hearing Smell Someone who suddenly loses the ability to identify objects by feeling them has probably suffered damage to what area of the cerebral cortex? parietal lobe temporal lobe frontal lobe corpus callosum The temporal lobe of the cerebral cortex is the primary target for which kind of sensory information? somatosensory, including touch the simplest aspects of vision gustatory Auditory A tumor in the temporal lobe may give rise to: flashes of light. visual hallucinations. olfactory hallucinations. prolonged yawning. Which lobe contains the primary motor cortex and the prefrontal cortex? occipital parietal temporal Frontal If the prefrontal cortex is damaged, an individual may: have difficulty remembering where they just put their keys. sleep 18-22 hours per day. have impaired vision. lose memory for faces. Which of the following brain imaging techniques does NOT provide a functional measure of brain activity? MEG EEG fMRI MRI An electroencephalograph measures: action potentials in an individual neuron. the electrical resistance of hair. the rate of glucose uptake in active regions of the brain. the average activity of the cells in a given region of the brain. An ablation is: an area of brain next to a blood vessel. a brain area that has been removed. a fluid-filled space in the brain. an area that has been damaged. So far, it appears that the brain feature most strongly correlated with intelligence in humans is the: volume of the hippocampus. brain-to-body ratio. brain weight. amount of gray matter.