DP- test 1
Charles S. Sherrington was the first to infer the properties of ____. A. synapses B. the refractory period C. the sodium-potassium pump D. dendrites and axons
A
Inhibitory synapses on a neuron ____. A. hyper polarize the postsynaptic cell B. weaken the cell's polarization C. increase the probability of an action potential D. move the potential closer to the cell's threshold
A
Nodes of Ranvier are ____. A.gaps in the myelin of axons B.also known as myelin sheath C.spiny outgrowths on dendrites D.responsible for cell metabolism
A
Sherrington found that repeated stimuli within a brief time have a cumulative effect. He referred to this phenomenon as ____. A. temporal summation B. spatial summation C. synaptic summation D. saltatory summation
A
The action potential of a neuron depends mostly on what movement of ions? A. sodium ions entering the cell B. sodium ions leaving the cell C. potassium ions entering the cell D. potassium ions leaving the cell
A
The two basic kinds of cells in the nervous system are _____. A.neurons and glia B.dendrites and axons C.ribosomes and lysosomes D.neurons and axons
A
What provides the building blocks for synthesizing all neurotransmitters? A. proteins found in the diet B. breakdown products of DNA C. breakdown products formed from other transmitters D. methane and ethanol
A
Which of the following describes the transmission of information in a local neuron? A. The signal decreases in strength as it travels .B. The signal increases in strength as it travels. C. The signal strength remains constant as it travels .D. Local neurons do not transmit any information.
A
Which statement is TRUE about the spontaneous firing rates of neurons? A. EPSPs increase the frequency. B. EPSPs decrease the frequency. C. IPSPs increase the frequency. D. One EPSP equals the effect of two IPSPs.
A
Protein channels allow ____ molecules to cross the cell membrane. A.large charged B.small charged C.large uncharged D.small uncharged
B
The presynaptic terminal stores high concentrations of neurotransmitter molecules in ____. A. axons B. vesicles C. peptides D. dendrites
B
What is the primary difference between temporal summation and spatial summation? A. Only spatial summation can produce an action potential. B. Spatial summation depends on contributions from more than one sensory neuron. C. Temporal summation produces a hyperpolarization instead of a depolarization. D. Spatial summation alters the response of more than one postsynaptic cell.
B
Autoreceptors monitor the ____. A. number of action potentials B. extracellular sodium concentration C. amount of neurotransmitter released D. amount of reuptake
C
What happens when a neurotransmitter is released by a presynaptic cell? A. It causes calcium to rush into the presynaptic neuron. B. It causes calcium to rush into the postsynaptic neuron. C. The neurotransmitter passively spreads across the synaptic cleft. D. The neurotransmitter is actively transported across the synaptic cleft.
C
What term describes the difference in voltage that typically exists between the inside and the outside of a neuron? A.concentration gradient B.generator potential C.resting potential D.shock gradient
C
When a membrane is at rest, what attracts sodium ions to the inside of the cell? A. an electrical gradient B. a concentration gradient C. both an electrical gradient and a concentration gradient D. neither an electrical gradient nor a concentration gradient
C
Adrenocorticotropic hormone (ACTH) controls secretions of the ____. A. gonads B. mammary glands C. thyroid gland D. adrenal cortex
D
Compared to inotropic effects, metabotropic effects are ____. A. quicker and briefer B. slower and briefer C. quicker and longer lasting D. slower and longer lasting
D
Electrical gradients lead to the? A. general movement of ions into the neuron B. general movement of ions out of the neuron C. movement of ions to areas having the same electrical charges D. movement of ions to areas having opposite electrical charges
D
Glial cells ____. A. are less numerous than neurons in the human brain. B. transmit information over long distances within the central nervous system. C. occupy about ten times more space in the brain than do neurons. D. are smaller but more numerous than neurons in the human brain.
D
Local anesthetic drugs attach to the sodium channels of the membrane, which ____. A. allows sodium ions to enter and stop action potential B. prevents potassium ions from entering and stopping action potential C. allows potassium ions to enter and stop action potential D. prevents sodium ions from entering and stopping action potential
D
What happens to a virus that manages to cross the blood-brain barrier and enter the brain? A. It is quickly destroyed by natural killer cells. B. It gets trapped in a neuron, and then both are destroyed by natural killer cells. C. It gets trapped in a glial cell, and then both are destroyed by natural killer cells. D. It remains there and may cause negative effects several years later.
D
