Quiz questions for systems phys

You are trying to design a new drug to painlessly euthanize animals. Your plan is to design a molecule that blocks the action of one of the following pumps/channels so that the heart muscle stays contracted and blood movement/flow is stopped. Which would be effective? A) Ca2+ ATPase pumps on SR membrane B) Na+/Ca++ exchangers on cell membrane C) Voltage gated Na+ channels D) None of these choices would result in sustained muscle contraction E) Na/K ATPase pumps on the cell membrane

Ca2+ ATPase pumps on SR membrane

Suppose you discover a chemical that can block leak potassium channels. What might happen as a result of this blockage? A) Na might have a larger influence on resting potential B) The Na/K pump activity might slow C) All of the answers are correct D) K would become less permeable

K would become less permeable

Which of the following would you find in the synaptic cleft of an alpha motor neuron and a muscle cell? A) acetylcholine B) calcium C) voltage-gated calcium channels D) acetylcholine re-uptake transporter E) dopamine

acetylcholine

During a marathon, Bob starts to feel his muscles wear down around mile 20. What could be happening in his brain/muscle at that point that's making him feel so fatigued? A) Inorganic phosphate as a result of so much ATP hydrolysis is inhibiting force B) Bob has used up all of his fat energy stores so none are left to fuel his continued performance C) Lactic acid is building up after all of that running D) Action potential firing from the brain to the muscle may be compromised E) More than one of these choices could explain what's happening

action potential firing from the brain to the muscle may be compromised

A hormone may be A) All of these choices are correct B) Inactivated by its target cell C) Activated by its target cell D) Inactivated by nontarget cells E) Excreted before it has a chance to act on a target cell

all of these choices are correct

In the dark... A) cGMP is high B) cGMP gated channels are closed C) Transducin is active D) The photoreceptor cell is firing action potentials E) The photoreceptor cell is hyperpolarized

cGMP is high

The prolonged electrical depolarization of cardiac muscle cells that occurs during contraction is primarily due to the persistent influx of what? A) sodium B) chloride C) calcium D) acetylcholine E) potassium

calcium

Cell B normally excites cell C. Cell A tonically inhibits the activity of cell B. Which of these cells would opioids most likely target directly? A) Cell C B) Cell B C) Cell A

cell A

Which of the following statements is FALSE? A) Ca2+ that activates contraction of smooth muscles can come from either the ECF or from the sarcoplasmic reticulum. B) Smooth muscle cells usually have one nucleus C) In the absence of any neural input, skeletal muscle cannot generate active tension D) Contractile activity of smooth muscle cells does not normally require Ca2+. E) Synaptic input onto skeletal muscle cells is always excitatory, whereas inputs to smooth muscle cells may be either excitatory or inhibitory.

contractile activity of smooth muscle cells does not normally require Ca2+

The resting potential of a neuron that is submerged in a solution with zero extracellular potassium will __________________ because __________________________. A) depolarize ; the driving force for potassium to exit the cell decreases B) depolarize ; the driving force for potassium to exit the cell increases C) hyperpolarize ; the driving force for potassium to exit the cell increases D) hyperpolarize ; the driving force for potassium to enter the cell increases E) hyperpolarize ; the driving force for potassium to exit the cell decreases

depolarize ; the driving force for potassium to exit the cell increases

If you block calcium channels on an axon, which will not occur? A) repolarization phase of the action potential B) graded potential C) depolarization phase of the action potential D) exocytosis of neurotransmitter E) hyperpolarization phase of the action potential

exocytosis of neurotransmitter

All other things being equal, if the concentration of calcium increases, the force will increase also in a linear fashion. A) True B) False

false

The calcium that permits neurotransmitter release from the alpha motor neuron is recycled and used as calcium that becomes available for the muscle contraction. A) True B) False

false

Organophosphates, which are found in a lot of insecticides, block the activity of acetylcholineesterase. What might be a result of blocking this important enzyme? A) Hyperstimulation of the nicotinic receptor B) Accelerated ACh breakdown in the synaptic cleft C) Muscle paralysis due to limited activity in the muscle cell

hyperstimulation of the nicotinic receptor

You have discovered a novel steroid hormone. You'd like to isolate its receptor as a part of your next project. Where should you look first? A) In the blood stream B) Any of these might be places where the receptor could be found. C) In the cytoplasm D) On the cell surface E) Within a membrane protein

in the cytoplasm

The L-type calcium channel opens by... A) Calcium efflux from the ryanodine receptor B) Binding of acetylcholine to the nicotinic receptors on the muscle cell membrane C) Potassium influx during repolarization D) Initial sodium influx during cardiomyocyte depolarization E) A local potential

initial sodium influx during cardiomyocyte depolarization

A ligand binds to a channel and opens it, resulting in the influx of sodium into a post-synaptic cell. The receptor and post synaptic response are... A) Ionotropic and inhibitory B) Metabotropic and inhibitory C) Ionotropic and neither excitatory nor inhibitory D) Metabotropic and excitatory E) Ionotropic and excitatory

ionotropic and excitatory

What is the role of calcium in chemical synaptic transmission? A) it flows into the post-synaptic cell, exciting it B) more than one of these choices is correct C) it aids vesicle fusion with the presynaptic membrane D) it aids the reuptake of neurotransmitters back into the presynaptic cleft E) it helps the action potential propagate down the presynaptic neuron

it aids vesicle fusion with the presynaptic membrane

In the transduction of sound, potassium plays an important role. How is it involved? A) It is responsible for voltage gated Na+ release B) It is pumped out of the hair cell by the sodium potassium pump C) It causes the release of neurotransmitter onto afferent neurons D) It flows from the endolymph into the hair cell, depolarizing it E) It flows from the endolymph into the hair cell, hyperpolarizing it

it flows from the endolymph into the hair cell, depolarizing it

Which of the following correctly describes the end plate potential (EPP)? A) It is primarily mediated by Na+ influx B) It is both a local potential in the end plate area of the muscle cell that allows the muscle cell to depolarize and it is primarily mediated by Na+ influx C) It is a local potential in the end plate area of the muscle cell that allows the muscle cell to depolarize D) It is a local potential in the alpha motor neuron that allows the muscle cell to depolarize E) It is both a local potential in the alpha motor neuron that allows a cell to depolarize and it is primarily mediated by Na+ influx

it is both a local potential in the end plate area of the muscle cell that allows the muscle cell to depolarize and it is primarily mediated by Na+ influx

A new element has been discovered!! Its name is Rutgeranium and its distribution in the extra- and intracellular fluid is still to be determined. Recently it was found that a ligand gated-Rutgeranium channel opened and resulted in an inhibitory post synaptic response. What can you conclude about Rutgeranium? A) It is positively charged and in higher concentrations in the extracellular environment compared to the intracellular B) It is negatively charged and in higher concentrations in the extracellular environment than the intracellular environment C) It is positively charged and in higher concentrations in the intracellular environment than the extracellular environment D) It is negatively charged and in higher concentrations in the intracellular environment than the extracellular environment E) It is either positively charged and highly concentrated OUTSIDE or negatively charged and highly concentrated INSIDE. F) It is either positively charged and highly concentrated inside OR negatively charged and highly concentrated outside.

it is either positively charged and highly concentrated inside or negatively charged and highly concentrated outside

The sodium potassium pump... A) pumps sodium and potassium down their gradients B) more than one of the above are correct C) all of the above are correct D) uses ATP to power its activity

more than one of the above are correct

Which of the following statements is NOT true of the endocrine system? A) It is an important regulator of homeostatic mechanisms B) It is one of two major regulatory systems of the body C) Most of its components are anatomically connected, like most other systems of the body D) It is composed of glands that secrete chemical messengers into the blood E) It influences and is influenced by the nervous system

most of its components are anatomically connected, like most other systems of the body

What would happen if tropomyosin couldn't change confirmation in the presence of Ca2+ binding to troponin? A) Myosin couldn't bind to actin B) ACh wouldn't be released from vesicles C) Ca2+ wouldn't be released from the SR D) Myosin couldn't bind to troponin E) Myosin couldn't bind to ATP

myosin couldn't bind to actin

Which of the these is a major difference between smooth and skeletal muscle? A) Myosin is the main protein that is regulated in skeletal muscle B) Myosin is the main protein that is regulated in smooth muscle C) Only skeletal muscle requires increased calcium ion concentration in the cytosol for contraction D) Only skeletal muscle has both actin and myosin E) Skeletal muscle usually exhibits spontaneous activity while smooth muscle cannot contract spontaneously

myosin is the main protein that is regulated in smooth muscle

Which of the proteins in involved in the contraction of smooth muscle is INCORRECTLY paired with its function? A) Myosin light chain phosphatase - removes the phosphate from actin B) Calmodulin - binds calcium C) Myosin - changes shape upon phosphorylation D) Myosin light chain kinase - adds a phosphate to myosin E) Actin - binds to myosin to generate force

myosin light chain phosphatase - removes the phosphate from actin

Which of the following statements about oxytocin is true?? A) Oxytocin is secreted by the anterior pituitary gland B) Oxytocin's main function is to increase the rate of respiration C) Oxytocin is synthesized by the hypothalamus D) Oxytocin keeps uterine smooth muscle from contracting, so it prolongs pregnancy E) Target cells of oxytocin have receptors for the hormone in their nucleus

oxytocin is synthesized by the hypothalamus

From back to front, the order of the cells in the retina are... A) photoreceptor cells, ganglion cells, bipolar cells B) photoreceptor cells, bipolar cells, ganglion cells C) ganglion cells, bipolar cells, photoreceptor cells D) ganglion cells, photoreceptor cells, bipolar cells

photoreceptor cells, bipolar cells, ganglion cells

The Ca2+ ATPase pumps on the sarcoplasmic reticulum membrane play an important role in muscle contraction. In patients with muscular dystrophy, there is some evidence that shows the expression of the Ca2+ ATPase pumps is diminished (there are fewer). Which of the following cellular effects may be a result of the diminished number of Ca2+ ATPase pumps? A) Reduced communication between the DHP receptor and the Ca2+ ATPase pumps B) Slowed activity of the Na/K pump C) Reduced communication between the DHP Receptor and the Ryanodine receptor D) Reduced Ca2+ uptake into the SR E) Reduced Ca2+ release through the RyR

reduced Ca2+ uptake into the SR

Which of the following is a calcium release channel? A) troponin B) ryanodine receptor C) DHP receptor D) nicotinic receptor E) tropomyosin

ryanodine receptor

Which of the following is a chemical sense? A) seeing B) mechanosensation C) hearing D) nociception E) taste and smell

taste and smell

You are designing an experiment to quantify the levels of stress experiences by different individuals. Which of the following tests would reveal insight as to a patient's chronic stress? A) Testing plasma levels of dopamine B) Testing plasma levels of follicle stimulating hormone C) Testing plasma levels of parathyroid hormone D) Testing plasma levels of cortisol E) Testing plasma levels of growth hormone

testing plasma levels of cortisol

Lo can be described as... A) The length at which a muscle produces maximum force or tension B) The length at which the actin and myosin molecules in a given sarcomere are all touching. C) The length at which a muscle produces maximum power D) The length at which a muscle produces maximum velocity or speed

the length at which a muscle produces maximum force or tension

Which is most directly responsible for the falling (repolarizing) phase of the action potential? A) the Na/K pump restores the ions to their original locations outside and inside of the cell B) the permeability to K+ increases while the permeability to Na+ decreases C) ATPase destroys the energy supply that was maintaining the action potential at its peak D) voltage gated Na+ channels are open E) the permeability to Na+ increases greatly

the permeability of K+ increases while the permeability to Na+ decreases

Which of the following does NOT correctly describe cardiac muscle cells? A) Their membranes are depolarized initially by the influx of sodium ions B) They depolarize prior to contraction C) They are arranged in layers surrounding hollow cavities in the heart D) They can contract in the absence of external calcium E) They are much shorter than skeletal muscle fibers and generally have a single nucleus

they can contract in the absence of external calcium

which muscle fiber type is always recruited first? A) Type IIa B) Type IIb C) Type I or type IIa, depending on the activity. D) Type IIx E) Type I

type I

A slow-twitch muscle fiber... A) All of the answers are correct. B) Will have more mitochondria than a fast-twitch muscle fiber C) Will fatigue faster than a fast-twitch muscle fiber D) Will cycle through the cross bridge faster than a fast-twitch muscle fiber

will have more mitochondria than a fast-twitch muscle fiber