BW 1 Physiology Past Paper PDF

1. l Conduction velocity in a neuron... 1. only depends on intensity of sodium current 2. depends on its space constant and the intensity of sodium current 3. depends on size, myelination and membrane capacitance but no...

1. l Conduction velocity in a neuron... 1. only depends on intensity of sodium current 2. depends on its space constant and the intensity of sodium current 3. depends on size, myelination and membrane capacitance but not sodium current intensity 4. only depends on the size of the axon (transverse diameter) and its being myelinated 2. G-protein-coupled receptors (pick the FALSE item): 1. may in uence intracellular levels of calcium ions, cyclic nucleotides, or AA 2. are involved in visual, olfactory, gustative and auditory sensory transduction 3. can mediate contraction and/or relaxation of smooth muscle 4. mediate responses to AD, NA, ACh, DA, 5-HT, Glu, GABA and neuropeptides 3. Smooth muscle contraction... 1. is based on regulation of actin by Ca 2+ 2. can be inhibited without interfering with either ion channels or membrane receptors 3. is regulated by cAMP and cGMP in opposite directions, in smooth muscles 4. depends on Ca entry at the plasma-membrane 2+ 4. The electrotonic properties of the neuron... 1. are the set of passive electrical characteristics of the neuronal membrane 2. are important in the generation of the action potential 3. de ne the excitability of the neuron 4. de ne the interaction between ion channels and membrane capacitance in neuronal membrane 5. The neuron res an action potential... 1. when the axon hillock is depolarized to a suf cient extent by the spatial and temporal summation of synaptic inputs 2. when no inhibitory synapses are activated on its dendritic- somatic region fi fi fl fi fi  3. when a suf cient number of presynaptic Glu receptors are activated 4. when the membrane potential of a dendrite is brought to the threshold for Na-channel opening. 6. Neurotransmitter release at the nerve terminal (pick the FALSE item)... 1. is a probabilistic, ‘quantal process’ 2. is controlled by protein-protein interactions that may be impaired by clostridial (tetanus, botulinus) toxins 3. may undergo either facilitation or depression, during repetitive activation, depending on the synapse and the mode of activation 4. is a high-af nity calcium-dependent process 7. A strong muscular activation 1. cannot be sustained a long time because the red bers become depleted of glycogen 2. requires a good perfusion of the muscle 3. will anyway activate red bers, initially, and gradually recruit white bers 4. will activate white bers rst because they are innervated by larger motor neurons in the anterior horn 8. Feed-forward control 1. is generally involved in modifying the state of a system /circuit 2. is generally involved in homeostatic mechanism 3. generally ampli es responses in a positive retroactive loop 4. is a mechanism to transform graded responses into a all-or none mechanism 9. An elevation of intracellular Ca concentration... 2+ 1. produces accumulation in the ER, which in turn activates protein synthesis 2. generally tends to produce active release of Ca2+ from the ER to transform it into an ampli ed but transient event fi fi fi fi fi fi fi fi fi  3. must be rapidly buffered by mitochondria before it reaches toxic levels 4. may produce either contraction or relaxation of contractile material in different cells 10. The cerebellum... 1. can perfectly handle the differential timing of muscle activation in producing a precise and smooth movement 2. receives input from canonical motor neurons in the cortex and activates mirror motor neurons 3. modi es movements in order to produce smooth and uid movement sequences 4. can handle the con ict between two motor programs 11. Sensory receptors... 1. in some cases may sustain continuous activity in response to a persisting stimulus, and are therefore de ned as ‘tonic’ receptors 2. generally possess a variable receptive eld, depending on the kind of stimulus 3. may be either tonic or phasic, and the presence of both kinds of receptor is important to be able to perceive both light and and intense stimuli 4. in most cases undergo more or less rapid adaptation, in response to a persisting stimulus, and in such cases they are de ned as ‘tonic’ receptors 12. A slight, prolonged skeletal muscle contraction... 1. is produced by activation of the end-plates at very low frequency 2. is produced by activation of a minority of the motor units that innervate the muscle 3. is produced by a continuous weak activation of the neuromuscular junctions 4. is produced by the alternate and coordinated activation of single motor units 13. A symport... 1. performs an asymmetric activity (has an intrinsically favored direction of transport) fi fl fi fi fi fl  2. is considered as ‘secondary active’ system but operates the transport of its substrates in the thermodynamically favorable direction 3. consumes cellular ATP in its molecular transitions 4. transports its substrates with a velocity proportional to substrate concentration 14. Dopamine in the basal ganglia... 1. simply shifts the balance between the ‘direct’ and ‘indirect’ pathway, facilitating overall movement 2. reaches the dorsal striatum from dopaminergic centers in the mesencephalic VTA 3. brings about motor learning by introducing plastic changes in striatal neurons 4. facilitates striatal neurons that originate the ‘indirect’ pathway 15. An ion channel (mark the FALSE item)... 1. if it is voltage-dependent, it will always be activated by membrane depolarization 2. favors the passage of ions in one direction vs. the other 3. has a main gating mechanism (e.g. ‘voltage’- or ‘ligand-operated’) but may be modulated by other factors 4. may respond to the binding of a ligand on its intra- or extracellular moiety, or to a change in membrane potential, or to a mechanical stimulus... 16.Central pattern generators in the spinal medulla... 1. mediate the withdrawal re ex triggered by painful stimulation 2. mediate the maintenance of posture 3. integrate ascending proprioceptive and descending motor control information 4. mediate the myotatic re ex 17. An inhibitory post-synaptic potential (IPSP)... 1. may interfere with the effects of a concurrent EPSP but not of a concurrent IPSP 2. will prevent the neuron from ring an action potential 3. can be produced by activation of GABA or glycine receptors, or by indirect activation of ion channels by alfa subunits of G-proteins fl fl fi 4. necessarily produces a hyperpolarization of the neuron 18. Visual information leaving the retina is carried by several afferent systems: 1. information about the overall light level in the environment arises from cones and reaches the supraoptic nucleus in the hypothalamus 2. the P system is particularly sensitive to slight differences in luminance and color 3. the M system is particularly sensitive to (rapid) changes in time and slight luminance 4. all the afferent inputs converge on the calcimine cortex (occipital area 17) 19. The burning sensation of pepper is generated at... 1. taste receptor for bitter 2. nociceptive receptors carrying TRP channels 3. taste receptors for umami 4. the combination of taste receptor and smell receptor activation 20. The activation of a retinic photoreceptor by light... 1. produces a depolarization of the photoreceptor and a consequent increase in glutamate release 2. produces activation of the underlying bipolar cell, independently of the activity of other photoreceptors 3. produces an increase of cGMP through the activation of the G- protein transducin 4. produces decreased release of glutamate which will produce opposite effects on the associate bipolar cell vs its neighbors 21. The action potential... 1. can be generated in dendrites and propagate to the neuronal soma 2. cannot be generated in cells that do not possess Na channels 3. only travels in neurons along the axon, away from the cell body 4. requires that outward recti er channels be present on the membrane fi  22. A primary active transport (pick the FALSE item...) 1. may be modulated in its ef ciency by post-translational modi cations 2. may carry more than one substrate 3. can obviously let the substrates through in one direction only 4. requires a suf ciently high ratio ATP/ADP to be able to operate 23. A sound, perceived by the ear, activates the hair cells in the cochlea: 1. the population of hair cells that are activated de nes the pitch of the sound 2. the discharge of hair cells that are activated is proportional to the intensity of the sound 3. the population of hair cells that are activated de nes the intensity of the sound 4. a sound produces pain when its intensity is > 10000 larger than the minimum perceived sound intensity 24. Sensory cells... 1. respond with spike ring rates proportional to the intensity of the stimulus 2. always posses transduction mechanism that convert the adequate stimulus into an electrical event 3. produce different responses depending on the kind of stimulus 4. are neuronal cells that are activated at the peripheral terminal and release neurotransmitter at the proximal terminal only 25. Intracellular receptors... 1. are involved in the action of insulin 2. mediate the action of hydrophilic transmitters/hormones 3. can respond to endogenous hormones as well as to exogenous substances 5. are associated to the internal face of the cell membrane 26. In skeletal muscles... 1. the force developed by the muscle cannot exceed the after load (load) 2. the preload does not have any effect on the force developed by the muscle fi fi fi fi fi fi  3. the after load determines the length of the muscle before it contracts 4. the velocity of shortening depends on the force that the muscle exerts on the load during contraction 27. The basal ganglia have all of the following roles except... 1. facilitate the initiation of voluntary movements 2. help in performing motor and cognitive behavioral shifts 3. modify movements to produce uid sequences of movements 4. coordinate the activation of single muscles to precisely perform a movement toward a target 28. The information from the retina directly reaches all the following structures but... 1. the suprachiasmatic nucleus of the hypothalamus 2. the amygdala 3. the superior colliculus in the mesencephalon 4. the lateral geniculate bodies of the thalamus 29. A physiological positive feedback mechanism is characterized by the following features (mark the WRONG statement): 1. the effect of the process in turn further activates the process 2. a certain level of activation must be achieved to trigger the process 3. there are mechanism (inactivation, saturation..) that turn the process off 4. a graded effect can be produced by nely regulating the process 30. Gamma motor bers.. 1. are activated when the muscle length changes 2. are activated by feedback from the spindle through IA and II afferent bers 3. are activated by the input from Golgi tendon organs 4. are activated to de ne the set-point for spindle activation 31. The energy for muscle contraction mostly derives from... 1. ketone bodies, when the muscle strongly contracts and cannot be perfused fi fi fi fl fi  2. FFA, when the muscle strongly contracts and cannot be perfused 3. glucose, when the muscle strongly contracts and cannot be perfused 4. glucose, when the muscle is well oxygenated 32. The control of eye movements... 1. is in uenced by vestibular information that guides foveation movements 2. is governed by the tectospinal projections that are controlled by the cerebellum, which constitutes the site of learning 3. is governed by the tectospinal projections that can be nely tuned and plastically modi ed (trained) by cerebellar control 4. is independent of visual information processing 33. Postsynaptic potentials (pick the WRONG statement)... 1. are time-variations of the membrane conductances that necessarily generate currents and changes in membrane potential 2. can occur at nerve terminals as well 3. can be either excitatory or inhibitory 4. can be produced by the activation of a GPCR 34. Long-term regulations in cell functions... 1. require the phosphorylation of proteins in the cytosol 2. are normally produced by signal molecules that can enter the cell and directly regulate transcription 3. often are produced by weak bonds between ligands and proteins 4. are typically produced via post-translational modi cations of transcription factors 35. The contraction of the muscle can be... 1. isotonic: the muscle contracts and the force it can develop depends on its length 2. isometric: the muscle contracts and the velocity of its shortening depends on its length and the load 3. isometric: the muscle contracts but the force it develops is smaller than the load fl fi fi fi 4. isotonic: the muscle does not shorten and the force it can develop depends on its length 36. The cerebellum has all of the following roles except... 1. precisely time the activation of single muscles to perform a movement 2. correct ongoing movements based on the input from the inferior olivary nucleus through climbing bers 3. precisely stop the movement at the target 4. modify movements to produce uid sequences of movements 37. Outward rectifying ion channels... 1. are activated by hyperpolarization of the cell 2. typically produce cell hyperpolarization 3. are involved in the positive feedback of action potentials 4. typically produce cell depolarization 38. A weak, stable contraction of a skeletal muscles can be obtained 1. by activating a few gamma bers 2. by weakly and continuously activating neuromuscular junctions 3. by activating a low number of motor units in the muscle at each moment 4. by reducing the extrusion of Ca and thus maintaining a stable 2+ intracellular level 39. The resting potential of a cell (mark the WRONG statement) … 1. is very sensitive to changes in extracellular Na+ and Ca2+ concentrations 2. depends on the concentration ratios of those ion species to which the membrane is permeable 3. is contributed to by the electrogenic activity of the Na/K-ATPase 4. indirectly in uences [Ca2+]CYT and therefore cellular respiration 40. Facilitation at synapses indicates … 1. short term phenomena that involve mostly presynaptic changes fl fi fl fi  2. medium-long term phenomena that involve mostly postsynaptic changes 3. medium-long term phenomena that involve mostly presynaptic changes 4. short term phenomena that involve mostly postsynaptic changes 41. Nociceptors … (mark the WRONG statement) 1. release glutamate, substance P and CGRP both at the dorsal horn in the spine and at peripheral terminals 2. can affect local vascularization 3. posses a subtype of TRP channels that can be activated by thermal stimuli as well as chemical compounds 4. are inhibited by the ‘gate mechanism’ 42. Peripheral receptor cells … 1. typically undergo adaptation, unless they are phasic 2. necessarily transduce the physical or chemical stimulus into an electrical event 3. do not respond to inappropriate stimuli 4. are always depolarized by the adequate stimulus 43. Cytosolic calcium-ion levels … 1. in uence mitochondrial calcium levels: slight increases in such levels produce mitochondrial suffering and decreased ATP production 2. are usually maintained by cells in the range 0.07-0.7 µM 3. can activate low-af nity processes without activating high-af nity ones provided the latter are slow in turning on 4. are kept as constant as possible by the calcium transport mechanism expressed in endoplasmic reticulum membrane 44. AMPA-receptors (glutamate receptors, GluR) … 1. contribute to synaptic plasticity because their expression, localization and modulation can be affected by neural activity 2. lead to the release of Ca from the ER 2+ 3. are blocked by Mg2+ unless the postsynaptic membrane is depolarized fl fi fi  4. are typically involved in triggering long-term potentiation and neuronal plasticity 45. Transcriptional effects may be produced … 1. by PKC, in response to increased Ca levels 2+ 2. by persistent increased cytosolic Ca levels 2+ 3. by growth factors, when they bind to their intracellular receptors 4. by thyroid hormones, through MAP kinase chains 46. Which of the following sentences is correct: 1. carriers can transport substrates against their concentration gradient is a speci c and saturable way 2. pumps can exploit the concentration gradient of one substrate to transport the other(s) against its gradient 3. channels typically are speci c, bidirectional, passive, regulated transport mechanisms 4. exchangers are speci c and saturable molecular devices that transport substrates in a preferential direction 47. The displacement of the hair cell in the cochlea … 1. opens an apical potassium channel which depolarized the cell due to the speci c composition of the endolymphatic uid 2. produces the opening of a Na-channel that depolarized the cell 3. occurs differentially along the cochlea depending on the intensity of the sound 4. produces a transmitter discharge by the hair cell that is proportional to the intensity of sound 48. Long-term potentiation may occur in response to all the following processes except … 1. release of NO by the postsynaptic neuron 2. phosphorylation of synapsin 3. activation of NMDA receptors 4. activation of GPCR receptors 49. Conduction velocity in an axon depends on … fi fi fi fi fl 1. the space constant of the axon, independent of Na-channel density 2. axon length 3. axon diameter, membrane resistance and therefore myelinization, current intensity during depolarization 4. the time constant of the axon 50. Muscle spindle contain … 1. nuclear chain spindle bers mostly innervated by IA afferent bers 2. Golgi tendon organs 3. contractile material con ned to the poles of the bers 4. nuclear bag bers that mostly respond to the static length of the muscle 51. In the basal ganglia circuit … 1. GABA+enkephalin neurons participate of the indirect pathway and project to the external pallidus 2. GABA+enkephalin neurons are inhibited by DA from the substantia nigra and directly project to the internal pallidus 3. GABA+enkephalin neurons participate of the indirect pathway and directly project to the internal pallidus 4. GABA+enkephalin neurons are facilitated by DA from substantia nigra and project to the external pallidus 52. The cerebellum is involved in (mark the INCORRECT statement) … 1. modifying movements to produce smooth sequence of complex movements 2. learning motor tasks 3. precisely timing the activation of single muscles in generating a smooth and precise movement 4. correcting movements while they are performed and sending feedback to the cortex even before the latter receives proprioceptive acknowledgment 53. MAPKSs are … 1. Protein kinases activated by monoamines 2. Mitogen-activated protein kinases fi fi fi fi fi 3. Protein kinases that phosphorylate MAP (microtubule-associated protein) 4. Kinases that are activated by intracellular receptors 54. Opsins … 1. are proteins that can capture photons and produce biochemical changes in response 2. are seven-membrane-domains proteins 3. are soluble proteins 4. are activated by the binding of retinal 55. Ryanodine receptors 1. are directly activated by conformational changes in skeletal muscle T-tubule calcium channels 2. are activated by IP3 3. are membrane receptors for the neurotransmitter ryanodine 4. are only activated by increase in cytosolic calcium level 56. The neuronal action potential 1. typically originates in neuronal body 2. only travels from the cell body toward the nerve terminal 3. is terminated by inactivation of Na channels, independently of K conductances 4. is terminated by inactivation of Na channels and concomitant activation of voltage dependent K channels 57. The action of dopamine on basal ganglia 1. consists in facilitating the indirect pathway 2. produces plastic changes that x learned heuristics, based on reinforcement 3. help the central executive of working memory in examining the motivational value of various behaviors 4. facilitates all movements by indiscriminately facilitating the activity of direct pathway 58. A weak, stable contraction of a muscle is obtained by … fi 1. activating all red bers in an coordinated, alternate way 2. producing a weak, stable contraction in all red muscle bres 3. stimulating a small number of red motor units only 4. activating white bers only 59. Which of the following statements is correct? 1. Gq produces an increase in cAMP 2. Gq activates phospholipase A2 3. Gq opens a calcium-channel 4. Gi/0 activates a potassium channel 60. Movement is perceived … 1. mostly through a direct involvement of area V5 bypassing Broadman areas 17-18 2. mostly through the ‘P’ visual pathway 3. mostly through the elaboration by the basal ganglia of information from the visual cortex 4. mostly due to the lateral inhibition mechanism 61. Vestibular-ocular re exes (mark the WRONG statement …) 1. involve the lateral and descending vestibular nuclei 2. are involved in nystagmus 3. can be modulated by cerebellar function 4. are involved in foveation 62. Olfactory receptors … 1. are epithelial receptor cells 2. produce a receptor potential by way of cyclic nucleotide-activated channels 3. have intrinsic tyrosine-kinase activity 4. are present in more than 1000 types in humans 63. In the retina … fi fi fl fi  1. amacrine and horizontal cells produce the differential sensitivity of bipolar cells to light hitting the center of the periphery of their receptive eld 2. a photoreceptor releases two different transmitters on ON-center or OFF-center bipolar cells 3. ON and OFF ganglion cells detect spatial differences in the light that hits different photoreceptors 4. a subpopulation of ganglion cells expresses a speci c opsin and is directly sensitive to light 64. Exchangers (‘antiport’ system) … 1. are typically able to transfer a solute against a concentration on ratio >20 2. transport substrates against their concentration gradient using energy released by hydrolysis ATP 3. may be sensitive to membrane potential 4. preferentially transport the substrates in one direction 65. Cochlear hair cells … 1. are involved in generating nystagmus 2. express Na/K-ATP at the apical membrane 3. release transmitter in response to K-conductance-induced depolarization 4. respond to vibrations in the range 1-1000 Hz 66. Solute transfer by a facilitated transport mechanism 1. occurs at a rate proportional to solute concentration 2. cannot exceed a certain rate 3. depend on the availability of ATP 4. preferentially occurs in one direction 67. Steroid hormone receptors 1. typically shuttle between cytosol and nucleus 2. are also called growth factor receptors 3. typically act by producing protein phosphorylation 4. posses tyrosine kinase activity fi fi 68. The appropriate shortening of a muscle in response to a graded activation … 1. is obtained by activating Golgi’s tendon organ when the muscle tends to shorten too much 2. is produced by the myotatic re ex because when the muscle shortens the spindle automatically becomes slack 3. is obtained by activating alfa motor neurons with the appropriate intensity through cerebellar modulation of the descending control 4. is obtained by shortening the spindles to the appropriate length through activation of gamma motoneurons 69. Voltage-dependent calcium ion channels (mark the INCORRECT statement) … 1. may be ‘low-voltage activated’ (T-type) and mostly produce electrical effects 2. are present on both the plasmalemma and the endoplasmic reticulum 3. typically are outward recti er channels 4. may be ‘high-voltage activated’ (L,N,P,Q-type) and mostly produce Ca2+ level changes 70. The blood-brain barrier limits the diffusion … 1. of large molecules because of a particularly dense basement membrane 2. of lipophilic substances because of the presence of tight junctions between endothelial cells 3. of hydrophilic substances because of tight envelope constituted by pericytes and astrocytes 4. of hydrophilic substances unless speci c transport systems are present 71. Purkinje cells in the cerebellum … 1. receive one-to-one projections from small granule cells 2. receive one-to-one projections from neurons of the inferior olivary complex 3. are glutamatergic neurons and activate neurons in deep nuclei fi fl fi 4. display relevant plastic modi cations at the climbing bers synapses 72. When a sound produces vibration in the scales of the cochlea 1. the discharge of transmitter by the excited cells is proportional to the intensity of the sound 2. the number of hair cells that are activated depends on the intensity of the sound 3. the number of hair cells that are activated depends on the bandwidth of the sound 4. the discharge of transmitter by the excited cells is proportional to the frequency of the sound 73. The occipito-parietal path of visual elaboration … 1. is referred to as the ‘what’ pathway 2. is important to perceive pro les 3. is referred to as the ‘where’ pathway 4. is important in perceiving ne color contrast 74. The steady-state concentration of a substance in the organism … 1. is equal to the ratio between rate of synthesis or intake (kg) and degradation rate 2. is kept constant by appropriate feed-forward mechanisms 3. is always equal to its set-point 4. depends on its oil water partition coef cient (i.e. lipophilicity) 75. The resting membrane potential … 1. is determined by membrane capacitance 2. is determined by the concentration ratios of permeable ion species 3. is determined by the current produced by the Na/K-ATPase 4. is determined by ion currents across the membrane 76. The effect of nigral DA on the striatum has the functions except… 1. generally facilitating the pathway that originates from striatal GABA+dynorphin+substance P medium spiny neurons 2. producing involuntary movements 3. producing long term plastic ganges at cortico-striatal synapse fi fi fi fi fi  4. selecting an shifting among behaviors by selectively facilitating / inhibiting speci c striatal paths 77. The information from the retina… 1. is channeled along two paths, for elaboration of detail and luminance (P path) or color and movement (M path) 2. necessarily stops in the superior colliculus to be relied to the lateral geniculate body of the thalamus 3. must be relayed to the pulvinar to elicit the ciliary re ex 4. directly reaches (only from melanopsin containing ganglion cells) the suprachaismatic nucleus of the hypothalamus. 78. The cerebellum has all of the following roles except: 1. precisely time the activation of single muscles to coordinate them in performing a movement 2. correct ongoing movements based on he input from the inferior olivary nucleus through climbing bers 3. precisely stop the movement at the target 4. modify and coordinate movements to produce uid sequence of movements 79. The term “facilitation” at synapses indicates … 1. medium-long term phenomena that involve mostly presynaptic changes 2. short term phenomena that involve mainly presynaptic changes 3. short term phenomena that involve mainly postsynaptic changes 4. medium-long term phenomena that involve mostly postsynaptic changes 80. Peripheral receptor cells … 1. produce a depolarization when activated by an adequate stimulus 2. selectively respond to a speci c physical or chemical signal and do not respond to other stimuli 3. necessarily transduce the physical or chemical stimulus into an electrical event 4. typically undergo adaptation: if they do so they are de ned as tonic fi fi fi fl fl fi  81. The rising potential of a cell (mark the WRONG statement) … 1. depends on the concentration ratios of those ion species to which the membrane is permeable 2. is not sensitive to changes in extracellular Na+ and Ca+ concentrations 3. in uences the cytosolic calcium movements and concentration, but not cellular respiration 4. is due to the electrogenic activity of the Na/K-ATPase 82. Gamma motor bers… 1. are activated by the input from Golgi tendon organs 2. are activated to de ne the set point for spindle activation 3. are activated by feedback from the spindle through IA and II afferent bers 4. are activated when the muscle length changes 83. Conduction velocity in an axon depends on… 1. the space constant of the axon but not the length 2. myelinization, but not current intensity during depolarization 3. axon diameter but not membrane resistance 4. the time constant of the axon and Na-channel density 84. Which of the following claims is false? 1. a number of potassium channels is usually open at rest in all cells 2. potassium channels can have many quite different molecular structures 3. in a speci c cell, potassium channels may favor either depolarization or hyperpolarization depending on the circumstances 4. potassium channels may open in response to depolarization, hyperpolarization, Ca+, alpha subunit of Gi and other factors 85. Long-term regulations in cell functions … (mark the WRONG statement) 1. may be produced by weak bonds between ligands and proteins, generally trough biochemical cascades 2. are normally produced by signal molecules that can enter the cell and directly regulate transcription 3. may require the phosphorylation of proteins in the cytosol fl fi fi fi fi  4. are typically produced via binding to, or post-translational modi cations of, transcription factors 86. In skeletal muscles … 1. the force developed by the muscle depends on the preload in case of isometric contraction, on the afterload in case of isotonic contraction 2. the muscle shortens during contraction of the force developed by the muscle is larger than the afterload 3. the velocity of shortening depends on the force that the muscle exerts on the load during contraction 4. the afterload determines the length of the muscle before it contracts 87. The blood-brain barrier … 1. limits solute diffusion due to the presence of tight junctions in astrocytes around vessels 2. prevents the passage to the brain of all hydrophilic solutes 3. limits the diffusion of lipophilic solutes due to the presence of tight junctions in the endothelium 4. limits solute diffusion due to the speci c preterites of the endothelium 88. The displacement of the hair cell int he cochlea … 1. produces a transmitter discharge by the hair cell that is proportional to the intensity of sound 2. opens an apical inward recti er channels 3. opens a potassium channel which lets potassium ions in from the endolymphatic uid 4. produces the differential activation of those hair cell that are tuned fro a speci c intensity of sound 89. Cytosolic calcium-ion levels … 1. in uence the mitochondrial calcium levels: slight increases in such levels produce mitochondrial suffering and decreased ATP production 2. are usually maintained by cells in the range 0.07-0.7 micro molar 3. are kept as constant as possible by the calcium transport mechanism expressed in endoplasmic reticulum membrane 4. can activate low af nity process without activating high-af nity ones provided that the latter are slow in turing on fl fi fi fl fi fi fi fi  90. TRP’s at nociceptive nerve endings do NOT respond to: 1. Thermal stimuli 2. In ammatory cytokines and prostaglandins 3. Acetylcholine 4. pH values outside the physiological range 91.Outward rectifying channels … 1. typically produce cell depolarization 2. preferentially let ions out of the cell 3. are involved in the positive feedback mechanism of action potentials 4. typically produce cell hyperpolarization 92. Postsynaptic potentials … 1. cannot be produced by the activation of a GPCR 2. arise from time-variations of the membrane conductances that generate synaptic currents 3. occur at dendrites and soma of neurons, but not at nerve terminals 4. can be either excitatory or inhibitory, depending on the location in the cell 93. An increase of Ca concentration at the postsynaptic site … 1. may produce either long-term potentiation or long term depression 2. may trigger production and retro-diffusion of NO, which activates PKC in the presynaptic element 3. can be produced by NMDA receptors, provided the postsynaptic membrane is hyperpolarized 4. may produce long term potentiation by activating calcineurin 94. Which of the following sentences is WRONG: 1. carriers can transport substrates along their concentration gradient in a passive, speci c and saturable way 2. pumps can exploit the chemical energy of a chemical reaction to favor the movement of substrates in a preferential direction, even against their electrochemical gradient 3. channels typically are speci c, bidirectional, passive, regulated transport mechanism fl fi fi  4. exchanger are speci c and saturable molecular devices that transport their substrates in a preferential direction 95. In order to produced a mild and stable contraction of skeletal muscles … 1. gamma bers alone must be activated 2. a small minority of motor units must be activated 3. motor units must be activated diffusely in the muscle, at low rate and in a coordinate way 4. extrusion of Ca must be decreased, thus maintaining a stable intracellular level 96. NMDA receptors … 1. contribute to synaptic plasticity because they are blocked by Zn unless the postsynaptic membrane is depolarized 2. contribute to synaptic plasticity because their expression, localization and modulation can be affected by neural activity 3. lead to the release of Ca from the ER 4. are typically involved in triggering long term potentiation and neuronal plasticity 97. Transcriptional effects may be produced … 1. by persistent increased cytosolic Ca levels which can activate “late genes” 2. by activation of kinases, such as PKC, in response to increased Ca levels, or PKA, through phosphorylations of DARP32 3. by thyroid hormones, through MAP kinase chains which lead to the phosphorylations of transcription factors 4. by growth factors , when they bind to their intracellular receptors and migrate to the nucleus 98. The control of eye movements … 1. is in uenced by visual information processing through the vestibulo.ocular re exes 2. is governed by the tectospinal projections that are controlled by the cerebellum, which constitutes the site of learning 3. is governed by the tectospinal projections that can be plastically and reversibly modi ed by cerebellar control 4. is in uenced by vestibular information that guides tracking movements through the optokinetic re ex fl fl fi fi fl fi fl 99.Golgi tendon organs… 1. send an input to the spine that activates gamma motor bers 2. signal muscle tension through type Il afferent bers 3. tend to produce relaxation of both agonistic and antagonistic muscles 4. are located in muscle spindles 100.Neuronal plasticity… 1. May occur following protein phosphorylation with no need for the activation of early or late genes 2. ensues in response to phosphorylation of synapsin 3. consists in medium-long term phenomena that typically involve both pre- and postsynaptic changes 4. can only be initiated by activation of NMDA receptors 101.The binding of a ligand to the extracellular site of a receptor produces its effects on a cell… 1. only if the receptor exposes an interaction site on the intracellular side of the membrane 2. by producing a conformational change of the intracellular portion of the molecule as well 3. by simply changing the conformation of the extracellular portion of the molecule 4. only provided the receptor is endocytosed 102.The resting potential of a cell... 1. is due to the electrogenic activity of the Na/K-ATPase 2. is very sensitive to changes in extracellular Na+ and Ca2+ concentrations 3. depends on the concentration ratios of all electrolytes 4. depends on the concentration ratios of those ion species to which the membrane is permeable 103.G-protein coupled receptors (pick the INCORRECT answer) 1. can mediate relaxation but not contraction in smooth muscle 2. may indirectly interfere with transcription 3. are involved in visual, olfactory, gustative and auditory sensory transduction 4. mediate responses to AD, NA, ACh, DA, 5-HT, Glu, GABA and neuropeptides 104.Ion channels: fi fi  1. inward rectifying channels produce cell depolarization 2. Outward rectifying ion channels are involved in the positive feedback of action potentials 3. if an ion channel is voltage-dependent, it will always be activated by membrane depolarization 4. K channels may produce either cell membrane hyperpolarization or depolarization 105.Transport mechanisms 1. channels constitute a passive, speci c, physiologically non saturable, regulated transport mechanism 2. pumps constitute a primary active, speci c, saturable, unidirectional transport mechanism 3. Carriers constitute a passive, speci c, non saturable, non regulated transport mechanism 4. exchangers constitute a primary active, speci c, saturable, non regulated transport mechanism 106.Nociceptors… 1. are sensory neurons that are inhibited by "gate mechanism" 2. release glutamate, substance P and CGRP both at the dorsal horn in the spine and at peripheral terminals 3. are affected by in ammatory mediation but cannot initiate in ammatory responses themselves 4. possess TRP channels which only act as sensors 107.Neurotransmitter release. …. (pick INCORRECT statement) 1. neurotransmitter release is regulated by SNAREs and monomeric G- proteins analogously to any other speci cally targeted vesicle fusion process 2. may undergo either facilitation or depression, during repetitive activation, depending on the synapse and the mode of activation 3. requires very high, local concentrations of Ca2+ and is an exergonic (thermodynamically favored) process 4. at the nerve terminal is a high-af nity calcium-dependent process 108.The blood-brain barrier.... 1. limits the diffusion of lipophilic solutes diffusion due to the presence of tight junctions in the endothelium 2. limits the passage to the brain of all hydrophilic solutes fl fl fi fi fi fi fi fi  3. limits solute diffusion due to the speci c properties of the endothelium 4. limits solute diffusion due to the presence of tight junctions in astrocytes around vessels 109.Regulation - pick the INCORRECT Statement: 1. weak bonds between ligands and proteins cannot produce long-term regulations in cells 2. long-term regulations in cell functions are typically produced via post-translational modi cations of transcription factors 3. signal molecules may enter the cell and directly regulate transcription 4. the activity of a process can be permanently modulated by modifying the transcription scheme in the cell through epigenetic modi cations 110.Pick the INCORRECT statement: 1. phosphorylation is a typical means to alter the function of a protein and it requires activation of a kinase 2. the function of proteins can be modi ed by pH 3. The binding of any ligand to a protein may rapidly and transiently modify its function or ef ciency 4. covalent modi cations of proteins are called post-translational modi cation and produce spontaneously reversible modi cations in protein function 111.Conduction velocity in an axon depends… 1. On the space constant of the axon, independent of Na channel density 2. only on the size of the axon (transverse diameter) and its being myelinated 3. on its space constant and the intensity of sodium current 4. on axon length 112.Calcium channels: 1. low voltage-activated calcium channels produce large increases in intracellular calcium 2. T-type calcium channels may produce bursts of action potentials if the resting potential is less negative 3. L-type calcium channels (typically get inactivated by depolarization 4. low voltage-activated calcium channels mostly produce transient electrical effects fi fi fi fi fi fi fi fi  113.The cerebellum... (pick the INCORRECT statement) 1. corrects ongoing movements based on the input from the inferior olivary nucleus through climbing bers 2. precisely stops the movement at the target by properly activating antagonistic- muscles at the end of the movement 3. precisely times the activation of single muscles to perform a movement 4. modi es complex series of movements to produce uid sequences of movements 114.The steady state concentration of a substance in a bodily uid depends... 1. on the concentration needed for its effect 2. on the ratio of formation (intake) to disposal (degradation) rates 3. on the difference between formation (intake) and disposal (degradation) rates 4. on the half-life of the substance 115.Physiological positive feedback... 1. is when the response of the system regulates another system 2. it helps to maintain a physiological parameter stable 3. can produce a nely graded effect 4. when the response of the system ampli es the response to the input 116.The Na/Ca exchanger(NCX) (pick the INCORRECT statement) 1. is the effective regulator of cytosolic calcium ion concentration 2. Is particularly effective in extruding large loads of Ca2+ ions 3. may produce a signi cant depolarizing current 4. is close to equilibrium (no net uxes) in resting healthy cells 117.Monomeric G-proteins... (pick the INCORRECT statement) 1. can work as quality control systems by acting as timers 2. can prevent the wrong amino-acid from being added to the protein growing sequence 3. can prevent the interaction of a vesicle with the wrong target 4. are constituted by an „a“ subunit with GTPase activity + a B-y subunit complex 118. Retinal opsins fi fi fi fl fi fi fl fl  1. Are photosensitive proteins due to their amino acid sequence and folding 2. Are expressed in different subtypes in cones and rods and this accounts for the different sensitivity to light of the two types of cells 3. are expressed not only in rods and cones 4. are sensitive to different wavelength bands due to binding to different pigments 119.Alpha-gamma motor neuron coactivation: 1. Is a normal way of activating muscle contraction, which brings about type Ia and II afferent activation if the mechanical result is not as expected 2. Is the mechanism that sustains the differential activation of red and white motor units 3. Is an occasional response elicited when muscle response does not re ect the efferent commands 4. occurs when upon stimulation the muscle lengthens instead of shortening 120.Cotransporters: 1. The NKCC (sodium-potassium-chloride carrier) uses energy from ATP hydrolysis to extrude chloride ions 2. The KCC (potassium-chloride carrier) tends to produce an increased intracellular chloride concentration 3. The NKCC (sodium-potassium-chloride carrier) tends to produce an increased intracellular chloride 4. the NKCC (sodium-potassium-chloride carrier) uses energy from ATP hydrolysis to extrude sodium ions 121.Eye movements: 1. are said to be optokinetic when they are intentional and aimed at keeping the target in the fovea 2. are said to be saccadic when they are produced by vestibular re exes 3. are exclusively controlled by the tectal nuclei 4. can be produced by auditory or tactile stimuli because of the multimodal hub function played by the superior colliculus 122.A strenuous contraction or a muscle 1. implies preferential use of FFA as energetic substrates 2. occurs when all motor units in it are activated at high frequency 3. occurs when the activation of the different motor units is properly alternated fl fl  4. is produced by activation of red bers, which are in lower need of oxygen 123.Intracellular calcium ion level... 1. triggers apoptosis when it exceeds 1 µM 2. can activate low-af nity processes without activating high-af nity ones 3. is maintained as constant as possible by the transport systems in the ER 4. cannot rise above 10 µM 124.NMDA receptors 1. are the only cellular mechanism sustaining synaptic plasticity and memory formation 2. are low-af nity glutamate receptors 3. contain a channel which need depolarization to gate open 4. are permeable to Na+, K+, Ca2+ but not Mg2+ 125.The muscle shortens: 1. At a velocity that depends on the difference between the maximum force the muscle can develop and the load 2. at constant velocity if the force developed by the muscle is constant 3. at constant velocity if the muscle is stimulated at a constant frequency 4. At constant velocity if the maximum force the muscle can develop equals the load 126.Which among the following hormones acts on intracellular receptors? 1. AVP 2. angiotensin 3. T3 4. insulin 127.Transport ATPases (mark the INCORRECT statement): 1. work in a reverse way by producing ATP under appropriate conditions 2. always transport the substrate in the same direction 3. can be used by cells to regulate pH in organelles 4. Are generally called pumps 128.White muscle bres 1. are controlled by motoneurons of a smaller size fi fi fi fi fi 2. are always activated rst in a mixed muscle 3. can sustain prolonged load 4. are recruited after red bers 129.The NCX (sodium calcium exchanger): mark the INCORRECT statement 1. is a high-capacity system that can transport large load of Ca2+ 2. produces a depolarization when it extrudes large quantities of Ca2+ 3. is sensitive to internal Na+ concentration 4. is the high-af nity system that sets (Ca2+)cyt to its resting level 130.Receptors 1. Steroid hormones acts through G-protein coupled receptors 2. Dopamine does have at least one receptor channel which is a ligand gated channel 3. Acetylcholine only has rapid, ion-channel coupled, receptors 4. Serotonin does have at least one receptor channel which is a ligand gated channel 131.The arrival of the action potential at the nerve terminal: 1. favours the process of spontaneous fusion of vesicles with the presynaptic membrane 2. produces a small but strategically localized ux of Ca2+ 3. produces the fusion of the docked vesicles by changing the local distribution of charges 4. produces entry of Ca2+ that favours the assembly of the fusion machine 132.Hair cells located at different positions in the cochlea: 1. the closer they are to the helicotrema the higher the pitch they respond to 2. Respond linearly with sound intensity at the appropriate sound-wave frequency 3. differentially respond to different sound wavelength due to different elasticity of the hair bundle 4. respond to different sound intensity 133.The action potential: 1. Is a difference in electric potential between the intracellular and external solutions fi fi fi fl  2. Propagates with a velocity which depends on the steepness of its rising phase 3. Can only be generated by cells that possess outward recti er Na+ current 4. Can only be generated in the central nervous system 134.Which of the following is correct? 1. in trimeric proteins, only the a subunit possesses functional actions 2. all the actions of trimeric G-proteins are mediated by second messengers 3. monomeric G-proteins are a main actor in receptor signal transduction 4. monomeric G-proteins have a GTPase activity 135.An excitatory post synaptic potential: 1. generally produces an action potential in the postsynaptic neuron 2. Is generally produced by a ligand-gated chloride conductance 3. is generally produced by a ligand-gated cation conductance 4. generally modulates biochemical responses in the postsynaptic element 136.Post-translational modi cations of proteins may produce all the following effects BUT: 1. spontaneously reversible changes in protein function 2. permanent changes in Structure/function of the cell 3. changes in transcription of speci c genes 4. changes in subcellular localization and enzymatic activity 137.The resting potential of the cell 1. always equals K+ equilibrium potential 2. is normally in uenced by the activity of outward rectifying conductance 3. in uences the ef ciency of the Na/Ca-exchanger 4. is determined by the average of the equilibrium potentials of the various ion species (Goldman's eq.) 138.Activation of the organ of Golgi 1. tendentially stiffens the involved joint 2. Tends to relax both agonist and antagonist muscles and gives input to central pattern generators 3. produces inhibition of the synonymous muscle and activation of the antagonists fl fl fi fi fi fi  4. Monitors muscle length 139.The blood-brain barrier 1. is based on the continuity of the envelopment of vessels by astrocyte pedicels 2. permits free traf cking of white blood cells 3. protects the brain by preventing amino-acid transmitters from entering it 4. is only permeable to lipophilic substances 140.Protein function... (pick the INCORRECT statement) 1. can depend on the subcellular localization 2. can be modi ed by pH 3. can be transiently modi ed by the binding of a ligand (ion, second messenger...) 4. can be transiently modi ed, in a spontaneously reversible way, by a post-translational modi cation 141.The most common trimeric G-proteins are 1. Gs, which stimulates adenylylcyclase, Gi which inhibits it and activates GIRK-channels, Gq which activates phospholipase C 2. Gs, which stimulates adenylylcyclase and opens Ca2+ channels, Gi which inhibits adenylylcyclase, Gq which activates phospholipase C 3. Gs, which stimulates adenylylcyclase and opens Ca2+ channels, Gi which stimulates phosphodiesterase, Gq which activates phospholipase C 4. Gs, which activates PKA, Gi which inhibits adenylylcyclase, Gq which activates PKC 142.An extracellular mediator (hormone or neurotransmitter) can produce effects in a cell 1. only if it covalently binds to its own receptor 2. only if it can cross the membrane 3. only if the receptor-ligand complex is endocytosed 4. by entering it or by binding to a membrane receptor 143.Motor units are constituted by a motor neuron and: 1. the set of muscle bers it innervates; if these are of the white type, then the motor unit will be activated before those that control red bers 2. the set of muscle bers it innervates; the size of the motor neuron typically is different if it innervates white or red bers fi fi fi fi fi fi fi fi fi 3. the set of muscle bers it innervates, which typically are concentrated in a region of the muscle 4. the set of muscle bers it innervates, which may be partly of the red and partly of the white type 144.Ionic movements. 1. Sodium concentration is about 2 times lower intracellularly than extracellularly 2. A large fraction of the energy extracted from ATP is used to maintain the correct intracellular levels of sodium and calcium ions 3. Chloride ions generally are close to electrochemical equilibrium (much lower inside the cell), but KCC transporter can increase and NKCC decrease intracellular Cl levels 4. The current generated by the Na/K-ATPase determines the resting potential of the cell 145.The action potential 1. is a momentary change in membrane potential due to a sequence of voltage-dependent channel responses 2. is the current that ows across Na+ channels in a positive feedback loop 3. is an impulse that propagates electrotonically 4. is the difference between intracellular and extracellular electric potential during an impulse 146.The concentration of a substance in the cell (or organism)... 1. can give information on the functionality of the elimination system, if its rate of synthesis is xed 2. does not depend on its lifetime 3. can only be increased by increasing the synthesis rate 4. depends on the difference between the synthesis/ absorption rate and the lifetime 147.Synaptic ef ciency... (mark the INCORRECT statement) 1. can undergo long-term (possibly permanent) changes in either direction, depending on the pattern with which the synapse is activated and the concurrent activity of the postsynaptic neuron 2. can be momentarily in uenced by residual Ca2+ from preceding stimuli or by phosphorylation of presynaptic proteins 3. can undergo long-term (possibly permanent) changes according to the amount of Ca2+ that enters the presynapse fi fi fi fl fl fi  4. can undergo long-term (possibly permanent) changes due to presynaptic changes determined by retrograde messengers from the post synapse 148.The cell's resting membrane potential … 1. is determined by K+ conductance 2. is contributed to by each ion as a result of its concentration ratio and membrane permeability 3. is determined by the various ions concentration ratios 4. is determined by the current generated by the Na/K-ATPase 149.Olfactory receptors... 1. can recognize a speci c odorant 2. are in all senses neurons 3. are modi ed epithelial cells and posses GPCRs for odorants 4. respond to a number of odorants by activating CAMP-sensitive ion channels and thus modulating secretion of glutamate on the rst afferent neuron 150.Homeostasis 1. consists in maintaining a stable equilibrium 2. is based on positive feedback mechanisms 3. does not require energy 4. is based on a continuous regulation of biochemical processes 151.Which among the following transport systems is passive, non- saturable physiologically, speci c, fully regulated? 1. a carrier 2. a pump 3. a co-transporter 4. an ion channel 152.Voltage-dependent calcium channels 1. can be high- or low-threshold activated -the latter type typically involves small Ca2+ uxes 2. typically inactivate quite rapidly upon depolarization, with the exception of L channels that never inactivate 3. can be of the L. N, T, or P, Q, R types - most contractile cells express predominantly T-type channels 4. can be high- or low-threshold activated - the former type typically involves large changes in cytosolic Ca2+ levels 153.Visual inputs... fi fl fi fi fi 1. are relayed by the retina along various paths, to intermediate stations and then to the cortex, the differential aspects of the information are discerned once it reaches the cortex 2. may or may not stop in the thalamus before reaching the appropriate cortical areas 3. are processed in the same way by all cones, but then they will undergo differential elaboration depending on the location in the retina 4. are elaborated in the retina to discern distinct aspects, such as luminance, color, spatial and temporal differences, and each of these aspects is then relayed to the cortex along a distinct pathway 154.Nociceptors.... 1. are activated by many different molecular receptors and transduction pathways, and may be either activated or inhibited by speci c GPRs 2. are blocked at their peripheral (sensing) terminal by local anesthetics 3. are activated by various physical and/or chemical stimuli, provided these are able (appropriate, suf ciently intense) to activate TR channels 4. like any other receptor cell, release their transmitter(s) at the afferent synapse only 155.Release of neurotransmitter upon the arrival of the action potential at the nerve terminal... 1. occurs because Ca2+ levels rapidly and massively rise in the cytosol 2. occurs thanks to the precisely localized entry of a few Ca ions where the vesicle is docked to the presynaptic membrane 3. occurs thank to the RAB-mediated translocation to the appropriate site on the presynaptic membrane 4. occurs because Ca2+ in ow activates CamKII that phosphorylates synapsin I and releases vesicles from the cytoskeleton 156.The cerebellum... 1. is particularly ef cient in modifying the activation of muscle groups in order to nicely coordinate a series of movements 2. is particularly ef cient in comparing motor and sensory signals to correct movements 3. is particularly ef cient in appropriately timing the concerted activity of motor neurons of a number of muscles to perform a precise movement fi fi fi fl fi fi  4. is particularly ef cient in picking the right movement in response to a speci c stimulus 157.Skeletal muscle bers... 1. produce a contraction strength that depends on the level of cytosolic Ca2+ 2. produce a contraction strength that depends (and can be regulated based) on the level of depolarization of the end-plate 3. produce a contraction strength that depends on the Ca2+ amount that enters through the sarcolemma 4. produce a contraction strength that depends on the length of the re, which is referred to as after-load 158.The blood-brain barrier. 1. does not let hydrophilic solutes through unless there are speci c transporters 2. can passively let glucose and aminoacids through to feed the brain 3. does not let lipophilic solutes through unless there are speci c transporters 4. is constituted by a fenestrated endothelium enveloped by closely intertwined protrusions of astrocytes 159.Permanent modi cations can occur in cells, but they are NOT generally produced by 1. activating membrane channels for monovalent cations 2. expressing speci c miRNAs 3. inducing changes in DNA conformation through epigenetic modi cations 4. producing post-translational modi cations of transcription factors 160.A positive feedback mechanism 1. helps maintaining a stable level for a process 2. can produce graded responses by nely regulating it 3. is a process that regulates another system 4. typically generates all-or-none response 161.The Na/Ca Exchanger … 1. may expel or import calcium, depending on membrane potential 2. is only expressed in muscle cells 3. Is a high-af nity, but low-capacity, transport mechanism 4. exchanges two Na+ for one Ca2+ fi fi fi fi fi fi fi fi fi fi fi fi  162.The post-synaptic potentials can be either excitatory or inhibitory: …. 1. in the latter case they might not actually involve any change in potential 2. they are excitatory when they are mediated by activation of a GPCR 3. in the former case they always consist in a depolarization, in the latter one in a hyperpolarization 4. they are excitatory when they are mediated by activation of an ion-channel-receptor 163.Skeletal muscles 1. mostly use glucose as an energy substrate when strongly activated 2. mostly use glucose as an energy substrate when aerobically activated 3. produce an isometric contraction when the force they can develop exceeds the load 4. Tend to undergo hypertrophy when activated in isotonic way 164.In the inner ear, the hair cells 1. in semicircular canals sense the shear of the uid moving along the canal 2. in otolith organs are depolarized by Na+ channels when the cilia are displaced 3. in the vestibular organs undergo depolarization or hyperpolarization depending on the direction the cilia are displaced 4. in the cochlea produce a ring rate that increases or decreases as the cilia are de ected in one or the opposite direction 165. An increased sensitivity to pain 1. all these statements are correct 2. may give rise to pain in response to non-noxious stimuli: this is called allodynia 3. may occur in the area of a lesion both because of axo-axonal re exes in nociceptors and release of in ammation-promoting factor by the nociceptor 4. typically occurs around an area where nociceptors have been activated: it is called hyperalgesia 166. Muscle contraction is de ned as … 1. isotonic the power produced by the muscle is constant 2. isometric: the afterload is greater than the preload fl fl fi fi fl fl  3. eccentric: the muscle contracts and shortens very slowly 4. isotonic: the force produced by the muscle during shortening at a constant velocity equals the afterload 167. During an increasing muscle activation... 1. the muscle initially works aerobically, then starts to work anaerobically as red bres get recruited 2. motor neurons that control red bres are activated rst, those that control white bres are only recruited if necessary 3. red bres are activated before white bres and fatigue earlier than the latter 4. since white bres rapidly fatigue, they are only activated at the beginning of an effort 168. The basal ganglia are important in. 1. Switching from one behaviour to the next 2. Precisely timing the activation of single muscle groups 3. Learning sequences and operating choices in motor but not cognitive behaviour 4. Detecting the correspondence between descending motor commands and proprioceptive information 169. The visible light waves range is: 1. 450(blue)-7000(red) nm (670-430 THz) 2. 4000(red)-8000(violet) nm (750-375 THz) 3. 4000(violet)-6000(red) nm (750-5000 THz) 4. 390(violet)-750(red) nm (770-400 THz) 170. In the muscle spindle. 1. type lA bers from muscle spindles signal muscle bre length, whereas type Il signal muscle tension 2. type lA bers from muscle spindles signal muscle bre length changes, whereas type I signal its static length 3. nuclear bag spindle bres mostly respond to the static length of the muscle 4. type lA bers from muscle spindles signal muscle re length changes, whereas type IB bres signal muscle tension 171. The displacement of the hair in the cochlear hair cell… 1. opens a potassium channel which lets potassium ions in from the endolymphatic uid 2. produces the differential activation of those hair cell that are tuned for a speci c intensity of the sound fi fi fi fi fi fi fi fl fi fi fi fi fi fi fi fi fi  3. opens an apical inward recti er channel 4. produces a transmitter discharge by the hair cell that is proportional to the intensity of sound 172. A photon that hits the retina... 1. may quite often cross a cone without being detected 2. must be absorbed by the pigmented layer If it has not reacted with a molecule of retinal 3. all these statements are correct 4. will almost certainly be captured by rhodopsin if it hits a rod 173. Nociceptors: 1. the typical transmitters of nociceptive neurons are substance P, glutamate and CGRP 2. all these statements are correct 3. in nociceptors: TRP channels can be modulated by intracellular processes (mostly through phosphorylation) 4. in nociceptors, TRP channels operate as receptor as well as effector molecules transducers 174. Calcium channels 1. Type calcium channels may produce bursts of action potentials if the resting potential is not negative enough 2. High voltage-activated calcium channels are involved in neurotransmitter release 3. High voltage-activated calcium channels generally have low conductance and rapidly inactivate 4. Low voltage-activated calcium channels produce large increases in intracellular calcium 175. Cotransporters: 1. the NKCC (sodium-potassium-chloride carrier) uses energy from ATP hydrolysis to extrude sodium ions 2. the KCC (potassium-chloride carrier) tends to produce an increased intracellular chloride concentration 3. Sodium-glucose cotransporters are needed by all cells in the organism fi  4. the NKCC (sodium-potassium-chloride carrier) tends to produce an increased intracellular chloride concentration 176. Outward rectifying ion channels. 1. are involved in the positive feedback of action potentials 2. typically produce cell hyperpolarization 3. typically produce cell depolarization 4. preferentially let ions out of the cell 177. Proton pumps: 1. proton pumps produce pH imbalance and transmembrane potential across intracellular membranes 2. pH imbalance across the membrane is the main driver of most symports and exchangers in intracellular organelles 3. respiratory complexes are proton pumps; mitochondrial ATP- synthase is a proton pump forced to work the other way around 4. all these statements are correct 178. Voltage operated channels.. 1. may be activated by cell depolarization or by hyperpolarization 2. can let through up to 1000 ions/s 3. are ionotropic receptors 4. constitute an example of facilitated transport mechanisms 179. An increase of Ca2+ concentration at the postsynaptic site.. 1. produces long-term potentiation 2. may trigger production and retro-diffusion of NO, which activates PKC in the presynapse 3. may produce either long-term potentiation or long-term depression 4. can be produced by NMDA receptors, provided the postsynaptic membrane is hyperpolarized 180. Calcium channels: 1. L-type calcium channels typically get inactivated by depolarization  2. b. low voltage-activated calcium channels are involved in neurotransmitter release 3. the main calcium-dependent responses of cells are typically triggered by opening low voltage-activated channels 4. low voltage-activated calcium channels mostly produce transient electrical effects 181. Intracellular receptors. 1. can respond to endogenous hormones as well as to exogenous substances 2. can mediate the action of hydrophilic transmitters/hormones 3. are associated to the internal face of the cell membrane 4. are involved in the action of insulin 182. Receptor transduction: 1. phosphorylation is the only mechanism by which the activity of a protein can be modi ed 2. second messengers cannot modulate voltage-dependent channels 3. phosphorylation may in uence the activity of voltage-dependent channels 4. the phosphorylation of substrates may change their function but will not in uence transcription 183. Cell resting membrane potential is produced by.. 1. the activity of voltage-dependent ion channels. 2. different concentrations and membrane permeabilities for the distinct ion species. 3. the electrogenic activity of pumps. 4. ionic currents in the cell at rest. 184. The action potential... 1. may typically be generated in dendrites and propagate to the neuronal soma 2. only travels in neurons along the axon, away from the cell body 3. duration is in uenced by potassium conductances fl fl fi fl  4. is generated at the axon hillock because it is the site where input impedance is maximal 185. The neuron res an action potential when 1. the axon hillock is depolarized to a suf cient extent by the spatial and temporal summation of synaptic inputs 2. no inhibitory synapses are activated on its dendritic-somatic region 3. the membrane potential of a dendrite is brought to the threshold for Na-channel opening 4. a suf cient number of presynaptic Glu receptors are activated 186. Long-term memory. 1. requires protein synthesis 2. all these statements are correct 3. typically involves epigenetic modi cations 4. may involve the ERK and MAP kinase pathways and/or PKC activation 187. Neurotransmitter release at the nerve terminal... (mark the WRONG statement) 1. requires very high, local concentrations of Ca2+ 2. is controlled by protein-protein interactions that may be impaired by clostridium (tetanus, botulinus) toxins 3. is a high-af nity calcium-dependent process 4. may undergo either facilitation or depression, during repetitive activation, depending on the synapse and the mode of activation 188. Synaptic plasticity (pick the INCORRECT statement): 1. facilitation at synapses indicates short term phenomena that involve mostly presynaptic changes 2. short- and long-term plasticity can occur through the activation of early and late genes, respectively 3. facilitation at synapses indicates medium-long term phenomena that involve mostly presynaptic changes 4. medium-long term plastic changes can be produced by NMDA receptors, GPCRs, growth factors, NO fi fi fi fi fi 189. Which of the following claims is correct? 1. Both chemical and electrical synapses can transmit uni-directionally 2. No exchange of intracellular components occurs at any synapse 3. At central synapses, release facilitation generally prevails on depression 4. The postsynaptic response only persists as long as the transmitter is there 190. Eye movements: 1. eye movements are in uenced by vestibular information that guides foveation movements 2. spontaneous eye movements are governed by the tectospinal projections, which can be plastically modi ed (trained) by cerebellar control 3. eye movements are independent of visual information processing 4. saccades are rapid eye movements always generated by subcortical activity fl fi