Synaptic Transmission and Nerve Fiber Properties

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 1) Any two EPSPs will override one IPSP. 1) MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 2) While a neuron membrane is depolarizing its ________. A) sodium gates are fully open B) chloride gates are partially open C) potassium gates are fully open D) chloride gates are fully open E) sodium gates are partially open 2) 3) Which of the following is true regarding unmyelinated nerve fibers in the PNS? A) Satellite cells cluster around each axon to form a pseudo-myelin sheath. B) A Schwann cell folds its plasma membrane around several fibers . C) An oligodendrocyte cells wraps its plasma membrane around each fiber as it does with myelinated fibers. D) A Schwann cells wraps its plasma membrane around each individual fiber as it does with myelinated fibers. 3) 4) An inhibitory local potential causes which of the following? A) Depolarization of the plasma membrane B) Neutralization of the plasma membrane C) Drifting of the membrane potential towards the resting membrane potential D) Hyperpolarization of the plasma membrane E) Repolarization of the plasma membrane 4) TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 5) Norepinephrine is a monoamine. 5) MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 6) If a neuron is prevented from sending a neurotransmitter across a synapse to another cell, which neuron property is being inhibited? A) Permeability B) Secretion C) Excitability D) Conductivity 6) 7) What property of neurons allows them to respond to changes in the environment? A) Excitablity B) Secretion C) Permeability D) Conductivity 7) TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 8) Nitric oxide (NO) acts as a neuromodulator by altering synaptic function. 8) MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 9) The respiratory center gathers information from a variety of sources in order to set the rate and depth of breathing. This is an example of what type of neural circuit? A) Convergent B) Parallel after-discharge C) Divergent D) Reverberating 9) 10) Which body system(s) is(are) dedicated to maintaining stable internal conditions by detecting and responding to stimuli? A) Nervous, endocrine, and integumentary B) Endocrine C) Nervous D) Nervous and endocrine 10) 11) Accumulation of Ca2+ in the axon terminal is called ________, and probably plays an important role in ________. A) neural coding; short-term memory B) postsynaptic potential; long-term memory C) long-term potentiation; long-term memory D) synaptic facilitation; short-term memory E) neural coding; immediate memory 11) 12) What is the most common type of neuron? A) Unipolar B) Bipolar C) Dendritic D) Multipolar E) Anaxonic 12) 13) In which part of a neuron is the postsynaptic membrane usually found? A) Dendrite B) Axon collateral C) Axon D) Axon terminal E) Perikaryon 13) - - 14) A cholinergic synapse uses ________ as its neurotransmitter. A) catecholamine B) monoamine C) acetylcholine D) epinephrine E) norepinephrine 14) 15) When the voltage of a plasma membrane shifts from +35 mV towards 0 mV, the cell is ________. A) reaching the threshold B) exiting the threshold C) depolarizing D) hyperpolarizing E) repolarizing 15) 16) Place the following events in synaptic transmission at a cholinergic synapse in order: A - A postsynaptic potential is produced; B - Voltage gated calcium channels open and calcium enters the cell; C - ACh is released and diffuses across the axon terminal; D - A nerve signal arrives at an axon terminal; E - Ligand gated sodium channels open and sodium enters the cell. A) B, D, C, A, E B) D, B, E, A, C C) B, C, D, E, A D) D, B, C, E, A 16) 17) If the potassium leak channels were suddenly blocked in a resting neuron, what would happen to its resting membrane potential? A) It would hyperpolarize. B) It would become more positive. C) The RMP would be unaffected. D) It would become more negative. 17) 18) How does a neuron transport enzymes produced in the neurosoma to its axon terminals? A) Through co-transport B) Via cytoplasmic streaming C) By diffusion D) Along microtubules 18) 19) A traveling wave of excitation is known as a(n) ________. A) nerve signal B) depolarizing signal C) local potential D) graded potential E) action potential 19) 20) What type of neural circuit is best for producing a prolonged output? A) A converging circuit B) A diverging circuit C) A presynaptic pool D) An autonomic pool E) A reverberating circuit 20) TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 21) In a myelinated fiber, only the initial segment in the trigger zone has voltage-regulated channels. 21) MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 22) What is another name for the autonomic nervous system? A) Visceral motor division B) Central nervous system C) Somatic sensory division D) Somatic motor division E) Visceral sensory division 22) TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 23) Memories are formed by neural pathways of modified synapses. 23) MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 24) Some antidepressant drugs act by inhibiting monoamine oxidase (MAO). What is the function of this enzyme? A) It converts ATP to cyclic AMP. B) It degrades acetylcholine. C) It breaks down monoamines. D) It blocks sodium channels. E) It binds to chloride gates. & 25) During the absolute refractory period which of the following is true? A) No stimulus of any strength will trigger a new action potential. B) The signal grows weaker with distance. C) If a neuron reaches threshold, the action potential goes to completion. D) It is possible to trigger a new action potential, but only with an unusually strong stimulus. E) The neuron fires at its maximum voltage if a stimulus depolarizes the neuron to threshold. 24) 25)