NPB 101 SAMPLE EXAM QUESTIONSHomeostasis is:a. an underlying principle of physiology.b. a dynamic steady-state.c. maintained by the process of regulation.d. only a and b are correct.e. a, b and c are all correct.The Na+/K+ ATPase pump of the axon of a neuron:a. is a lipid molecule in the membrane.b. pumps 2 Na+ ions for every 2 K+ ions.c. establishes the ion gradients for Na+ and K+d. only a and b are correct.e. a, b and c are all correct.The Nernst potential is:a. the membrane potential of the cell.b. a log relationship of the ratio of the concentration of an ion outside relative toinside the cell.c. determined by the ion channel leaks for sodium and potassium.d. only a and b are correct.e. a, b and c are all correct.Ion permeability (Pi) is:a. determined by the availability of ion channels for ion “i” in the membrane.b. may be altered by various stimuli, including mechanical, chemical and electricalstimuli.c. directly related to the electrochemical equilibrium for ion “i”.d. only a and b are correct.e. a, b and c are all correct.If a neuron were experimentally stimulated at both ends simultaneously:a. the action potentials would pass in the middle and travel to the opposite ends.b. the action potentials would meet in the middle and then be conducted back to theirstarting positions.c. the action potentials would stop as they met in the middle.d. the stronger of the two action potentials would override the weaker actionpotential.e. summation would occur when the action potentials met in the middle, resulting ina larger action potential.An action potential conducted down an axon requires the presence of:a. voltage-stimulated Na+ channels.b. Na+/K+ ATPase electrogenic pump.c. voltage-stimulated Ca++ channels.d. only a and b are correct.e. a, b and c are all correct.Two adjacent axon terminals, one from neuron A, the other from neuron B, synapse on a third neuron C. The two axon terminals simultaneously release transmitter eliciting an action potential in neuron C. This is an example of:a. convergence.b. temporal summation.c. spatial summation.d. only a and b are correct.e. only a and c are correct.At an excitatory synapse an action potential in the:a. postsynaptic neuron depolarizes the presynaptic membrane.b. presynaptic neuron increases the permeability of the postsynaptic membraneto Na+ and K+.c. presynaptic neuron increases the permeability of the postsynaptic membrane onlyto K+.d. only a and b are correct.e. a, b and c are all correct.Tonic receptors:a. are useful in signaling the stimulus level to the nervous system.b. are primarily proprioceptors.c. adapt rapidly.d. only a and b are correct.e. a, b and c are all correct.Which of the following is not a graded potential?a. excitatory postsynaptic potential.b. inhibitory postsynaptic potential.c. generator potential.d. action potential.e. a, b, c and d are all graded potentials.The pitch of a sound is:a. determined by the frequency of vibrations of air moleculesb. measured in decibelsc. perceived as sound waves move over the helicotrema of the inner eard. only a and b are correct.e. a, b and c are all correct.High- and low-frequency sounds are discriminated chiefly by:a. low frequencies producing stronger vibrations.b. high frequencies producing larger action potentials.c. the middle ear bones vibrating more vigorously for low frequencies.d. low frequencies deflecting the basilar membrane at a greater distance fromthe oval window.e. low frequencies setting up fluid vibrations in the perilymph.Stimulation of a photoreceptor by light causes:a. hyperpolarization of the photoreceptor and reduction in the synaptic release of LGlutamate.b. depolarization of the depolarizing bipolar cell by opening Na+ channels.c. excitation of the ganglion cell synaptically connected to the depolarizing bipolarcell.d. only a and b are correct.e. a, b and c are all correct.An individual that suffers extensive damage to the right occipital lobe would have:a. loss of vision from the left eye.b. loss of vision from the right eye.c. loss of vision from the left visual field.d. loss of vision from the right visual field.e. none of the above are correct.Reflexes are:a. stereotyped responses to a fixed stimulus.b. seen in the reflexes of motor control where a sensor activates an afferent fiberwhich in turn, either monosynaptically or via interneurons, alters the activity ofmotorneurons and the muscles to which it is synaptically connected.c. seen only in the autonomic nervous system.d. only a and b are correct.Which of the following does not directly influence the lower motor neurons?a. primary motor cortex.b. cerebellumc. brain stem.d. Afferent neurons (monosynaptically or through interneurons).e. none of the above are correct.Intrafusal muscle fibers are:a. innervated by alpha motor neurons.b. found within muscle spindles.c. sensory nerve endings that are activated by muscle tension.d. only a and b are correct.e. a, b and c are all correct.Parkinson’s disease:a. is associated with a deficiency of serotonin.b. is characterized by a resting tremor.c. is characterized by an intention tremor.d. only a and b are correct.e. only a and c are all correct.The sympathetic nervous system:a. is always excitatory.b. dominates (is excitatory) in fight or flight situations.c. innervates only tissues concerned with protecting the body against challenges fromthe outside environment.d. only a and b are correct.e. a, b and c are all correct.Which of the following statements concerning negative feedback is incorrect?a. negative feedback exists when a change in a regulated variable triggers a responsein the controlled system that opposes the change.b. negative feedback exists when the input to a system increases the output and theoutput limits its own production by inhibiting the input.c. with negative feedback, a control system’s input and output continue toenhance each other.d. most of the body’s homeostatic control mechanisms operate on the principle ofnegative feedbacke. a, b, c and d are all correct.The sense of taste arises from:a. varying combinations of five primary tastes: salty, sour, sweet, bitter and umami.b. stimulation of chemical receptors located in taste buds.c. stimulation of chemical receptors which have a life span of approximately 10 days.d. only a and b are correct.e. a, b and c are all correct.Smell, or olfaction, is:a. sensed by primary chemical receptors located in the roof of the nasal cavity.b. a rapidly adapting sense.c. the result