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1) the Resting Membrane Potential Is: A) 0 Mv, Charge Is Balanced at Rest

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1) the Resting Membrane Potential Is: A) 0 Mv, Charge Is Balanced at Rest 1) The resting membrane potential is: a) 0 mV, charge is balanced at rest b) Negative inside because potassium can diffuse out of the cell c) Negative inside because Cl- concentrations are higher inside the cell d) Negative outside because sodium can diffuse into the cell 2) Which of the following is a true statement about cells in the resting state : a) Chloride moves into the cells because the concentration of chloride is higher inside the cell than outside the cell b) Large anions (A-) moves out of the cell because it has a higher concentration inside the cell than outside the cell c) Sodium moves into the cell because it has a higher concentration outside the cell than inside the cell d) Voltage gated sodium channels are closed 3) The action potential threshold stimulus causes: a) chloride to enter the cell b) Voltage gated sodium and potassium channels to open c) Voltage gated sodium channels to inactivate d) Release of Ca++ from the axon 4) Cardiac muscle: a) Is striated b) Has no electrical connection between cells c) Is not striated d) Has cells that are long and unbranched 5) This causes vesicles to migrate and release of neurotransmitter in the chemical synapse: a) Increased dopamine b) Monoamine oxidase c) Increased calcium d) Increased potassium 6) Prozac increases the amount of serotonin present in the synapse by: a) Acting as a selective serotonin reuptake inhibitor b) Increasing tryptophan levels c) Blocking the enzymatic degradation of serotonin d) Increasing serotonin synthesis 7) When the sarcomere shortens: a) Calcium levels decrease b) Myosin pulls on the actin filament c) ATP must not be present d) Potassium is bound to troponin 8) This negatively charged ion is found at high concentrations (i.e., 120 mM) outside the cell: a) Sodium b) A- c) Chloride d) Bicarbonate 9) Excitable cells such as neurons a) Have a resting membrane potential of around +35 mV b) Have a resting membrane potential of around -70 mV c) Have internal potassium concentrations that are the same as potassium concentrations outside the cell. d) Have a resting membrane potential of around 0 mV 10) Smooth muscle cells are: a) striated b) longer than skeletal muscle cells c) connected to each other by gap junctions d) used by the hand for gripping 11) This cord-like protein physically covers the myosin binding sites of actin, preventing muscle contraction unless calcium is present: a) Unsaturated fatty acid b) desaturase c) Tropomyosin d) Myosin 12) The diagram below shows voltage gated channels. When the voltage gated channels are in this state: a) The membrane potential will remain stable b) Sodium will leave the cell c) The membrane potential will rapidly become more positive d) The membrane potential will become hyperpolarized 13) If a person has reduced levels of serotonin, this results in: a) Clinical depression b) Male erectile disfunction c) paralysis d) Schizophrenia 14) Which isoform of myosin listed below is used for slow endurance muscle contraction: a) Type I b) Type IIx c) Type IIa d) Type Ib 15) Calcium induces muscle contractions by a) Causing actin monomers to assemble into a filament b) Depolarizing the membrane c) making ATP available to bind to myosin head d) allowing the myosin head to bind to actin filament 16) Type II myosin is: a) found in fast twitch muscle fibers b) found in slow twitch muscle fibers c) only found in rodents d) activated by chloride 17) The effect of having Schwann cells and nodes of ranvier on axons is: a) to slow down action potential propagation b) to increase the height of the action potential peak c) to speed up action potential propagation d) to decrease the height of the action potential peak 18) the picture above shows: a) A motor neuron innervating a smooth muscle fiber b) An electrical synapse c) The cross section of a skeletal muscle fiber d) The serotonergic synapse 19) The thick filaments of the sarcomere are made out of: a) Actin b) Myosin c) Sarcoplasmic reticulum d) sarcoplasm 20) When a membrane depolarizes, the membrane potential becomes: a) More negative b) More positive c) Stays the same d) Speeds up 21) Which of the following allows the muscle to contract: a) Calcium release from the sarcoplasmic reticulum b) Norepinephrine taken up into the axon terminus c) Actin pulling on other actin filaments d) Release of nitric oxide (NO) 22) Tetrodotoxin: a) Blocks chloride channels b) Blocks myosin binding to actin c) Is found in pufferfish d) Opens voltage gated potassium channels 23) Skeletal muscle cells a) Are always dividing b) Are always short in length c) Are found in the small intestine d) Are also called muscle fibers 24) In muscle contraction and sarcomere shortening: a) Acetylcholine binds to myosin b) ATP causes myosin to unbind from actin c) Muscle contraction cannot occur if calcium is present d) Acetylcholine binds to actin 25) The duration of the action potential is: a) A few nanoseconds b) A few milliseconds c) Several seconds d) A few minutes 26) When the voltage gated channels of the neuron are in the configuration shown above: a) The membrane potential stays at +30 mV for several minutes b) Potassium diffuses out of the cell making the membrane potential more positive c) The membrane potential drops back to the resting potential d) Potassium rapidly diffuses into the cell 27) In the sliding filament model of muscle contraction: a) Hydrolysis of ATP causes the myosin head to cock b) Hydrolysis of ATP causes calcium to bind to actin c) The release of ADP and Pi causes the myosin head to attach to actin d) The release of ADP and Pi causes calcium to bind to actin 28) Substance P is involved in: a) Thermal regulation b) Osmoregulation c) Nitrogen wastes d) Pain 29) Which of the following is an amino acid neurotransmitter: a) Dopamine b) Carbon monoxide (CO) c) Calcium d) Glycine 30) The head of the myosin cocks when: a) ATP binds to it b) ATP is hydrolyzed to ADP and Pi c) ADP and Pi are released d) ATP is synthesized from ADP and Pi 31) What can happen when neurotransmitter binds to ion channels on the post synaptic membrane? a) Ion channels open b) a depolarization or hyperpolarization occurs c) a depolarization is stimulatory d) all of the above 32) The sodium-potassium ATPase a) Pulls against myosin in muscle contraction b) Makes [K+] higher inside the cell and [Na+] higher outside the cell c) Is a neurotransmitter d) pumps 3 K+ out of the cell and 2 Na+ into the cell at the expense of 1 ATP. 33) The propagation of the action potential along an axon: a) can be as high as 10 meters per second or 22 mph b) can be as high as 100 meters per second or 225 mph c) can be as high as 1000 meters per second or 2250 mph d) can be as high as the speed of light .
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