HPHY 322
What is the order, from smallest to largest, for a muscle? A) Myofilament, Myofibril, Muscle fiber, Muscle fascicle, Muscle B) Myofibril, Muscle fascicle, Muscle fiber, Myofilament, Muscle C) Muscle, Muscle fascicle, Muscle fiber, Myofibril, Myofilament
A) Myofilament, Myofibril, Muscle fiber, Muscle fascicle, Muscle
Specifically, what is "troponin I" bound to in the sarcomere?
Actin
Which of the following is a step in photoreception in the rods? A) Light converts all-trans retinal to 11-cis retinal B) Metarhodopsin II activates transducin C) Cyclic guanosine monophosphate (cGMP) levels increase D) Rods depolarize E) Glutamate release increases
B) Metarhodopsin II activates transducin
Which of the following are true of the smell pathways? A) The pre motor cortex is responsible for analysis of smells. B) The hypothalamus and the limbic system are responsible for the salivation reflex. C) The hypothalamus is responsible for the memory of food likes and dislikes. D) All of the above E) Only B and C
B) The hypothalamus and the limbic system are responsible for the salivation reflex.
Thinking about cell to cell communication between pre and post synaptic neurons, identify whether each statement is TRUE or FALSE. True/False: Binding of acetylcholine to receptors on the post synaptic neuron causes opening of voltage-gated calcium channels.
B. False
When sodium ions are pumped against their concentration gradient across the cell membrane, this process requires energy. What is the best term used to describe this type of ion movement? a. Simple Diffusion b. Facilitated Diffusion c. Active Transport d. Nernst Potential
C. Active Transport
Which of the following statements is true? A) the perilymph contains more potassium than the endolymph B) the endolymph contains more potassium than the perilymph C) the bottom of the hair cells are saturated in perilymph D) B & C E) A & C
D) B & C
Which of the following contribute to hearing pitch: A) type of hair cell B) region of the basilar membrane vibrating C) tonotopic arrangement of the auditory cortex D) all of the above
D) all of the above
In the flexor withdrawal reflex pathway, what is the purpose of the inhibitory interneuron? A) to activate the antagonist muscle B) to relax the agonist muscle C) to activate the agonist muscle D) to relax the antagonist muscle
D) to relax the antagonist muscle
Which of the following is/are TRUE of the cell membrane? a. The cell membrane is composed of a lipid bilayer b. The cell membrane is selectively permeable, meaning it only allows certain molecules and ions to cross the membrane c. Trans-membrane proteins allow ions and molecules that are not lipid soluble to cross the cell membrane d. All of the above are TRUE e. Only A and B are TRUE
D. All of the Above
Name the special area of the brain that is responsible for (among other functions) our understanding and utilization of words and sentences to communicate.
Dominant Wernicke's area
Which of the following involving sense of hearing are correct? A. Impedance matching will convert high pressure, high displacement vibrations of air into low pressure vibrations suitable for driving cochlear fluids B. The tympanic membrane has low impedance compared to the oval window which has high impedance C. The middle ear functions to match impedance of the outer ear and the cochlea D. A and B E. B and C
E. B and C
True (a)/ False (b): The M-wave amplitude represents the sum of the action potentials that occur in the skeletal muscle fibers being electronically monitored. Therefore, an increase in the frequency of stimulation either artificially over neuron axons, or physiologically in the spinal cord, will both lead to an increase in the M-wave amplitude of the muscle fibers being monitored.
False
True (a)/ False (b): When stimulating motor neuron axons artificially with a bar stimulus electrode, increasing the frequency of the stimulus applied can cause an increase in the number of motor neurons in the median nerve that reach threshold.
False
True or False: Deflection of steriocilia towards the longest cilium causes an influx of sodium leading to depolarization
False
True or False: Light absorption on the retina activates the protein opsin, which leads to a signal cascade to decrease levels of cAMP in the cell
False
True or False: Tonotopic arrangement of the basilar membrane facilitates different volumes of sound to be perceived
False
True or False: When vision is perceived, the firing rate of the activated photoreceptor cells increases, leading to more activation in the occipital cortex
False
You are working with a computer simulation of a spinal cord reflex. On your computer screen you can visualize the afferent neuron, the interneurons in the spinal cord, the efferent neurons, and the corticospinal neurons descending from the cortex and synapsing onto the interneurons and/or efferent neurons. You can also visualize the degree of muscle stimulation in the agonist and antagonist muscles, and the amplitude of movement from the reflex. True (a)/ False (b): You reset your simulation, and this time, you decrease the frequency of EPSPs from descending corticospinal neurons directly onto the interneurons that then synapse with the efferent motor neurons to the antagonist muscle only (with no change to the EPSPs directly onto the efferent motor neurons to the agonist muscles). The expected outcome is an increase in the amplitude of the reflexive movement.
False
The drug that is believed to have led to pop star Michael Jackson's death is Propofol. Its mechanism of action is to create a conformational change in the protein that makes-up the post-synaptic GABA-receptors. GABA is a neurotransmitter that, when bound to its receptor, opens chloride channels. The drug causes the channels to remain in the open position for a prolonged period of time. Based on this information, indicate whether the following statements are true or false related to the plausibility of the outcome of Propofol use. True/False: This drug is a stimulant, and is used to increase the frequency of neuron firing. a. True b. False True/False: The expected outcome for short term use (~5 minutes) would be a decrease in firing frequency of any neuron with GABA receptors and that has been in contact with Propofol. a. True b. False
False True
What is the name of the region of the sarcomere that is composed of only thick filaments (myosin) and does not overlap with the thin filaments (actin)?
H zone or H band
Name the band/zone in the sarcomere that shortens when the sarcomere shortens. ___________________________
I and H
The __________________________ maintains the concentration gradients for Na+ and K+ across the neuron membrane.
Na+/K+ ATPase pump
What type of receptors does acetylcholine bind to at the neuromuscular junction? (Be specific)
Nicotinic Cholinergic
Name the type of receptors found at the neuromuscular junction, and on post-ganglionic neurons of the autonomic nervous system. Use terminology that communicates which ligands can bind to the receptors.
Nicotinic cholinergic
When the Gq protein is activated, this stimulates the protein _____________________, which causes the conversion of PIP2 into _______________ and _____________________.
Phospholipase C IP3 DAG
During an action potential, the repolarization phase is predominantly caused by the movement of what ion? Include the name of the ion and whether influx or efflux occurs.
Potassium ion efflux
What is the term used to describe the period of a nerve cell action potential during which another action potential can be initiated, but it requires a stronger stimulus than normal to initiate another action potential?
Relative refractory period
Where is there the highest concentration of calcium in a muscle cell?
Sarcoplasmic reticulum, SR, terminal cisternae
What is the term used to describe when excitatory inputs from multiple pre-synaptic stimuli that are each individually below threshold are initiated at the same time to create an adequate stimulus at the trigger zone to reach threshold and trigger an action potential? (be specific)
Spatial summation
You introduce a drug that binds specifically to ATP in the sarcoplasm (but does not affect other cells in the body) and makes it unable to be used and broken down in the muscle cell. This includes ATP involved in cross-bridge cycling and ATP involved in the active pumping of calcium back into the sarcoplasmic reticulum. Which of the following would you expect to occur in these circumstances? a. The muscles produce no tension and they will feel limp b. The affected sarcoplasm will have no intracellular calcium ions c. The intracellular calcium ion concentration will increase d. Only A and B
The intracellular calcium ion concentration will increase
In order for cross-bridge cycling to occur, myosin must bind to the actin binding sites. What is the name of the molecule or structure that covers these actin binding sites when the muscle cell has not been stimulated and calcium is not present inside the cell?
Tropomyosin
Name two regulatory proteins found in the sarcomere (as opposed to supportive or contractile proteins).
Troponin and Tropomyosin
During skeletal muscle contraction, calcium enters the cell to help facilitate cross-bridge cycling. What does calcium bind to inside the muscle cell? (be specific)
Troponin-c
True (a)/ False (b): When motor neurons are stimulated physiologically by corticospinal pre- synaptic neurons in the spinal cord, an increase in the frequency of the EPSPs would lead to temporal summation and an increase in the number of motor neurons that reach threshold.
True
True (a)/False (b): A decrease in the concentration of potassium in the endolymph would render the hair cells less sensitive, and require either more ion channels to open, or ion channels to open longer, to produce the same degree of depolarization compared to normal.
True
True (a)/False (b): If hearing in one ear were completely lost, the person would not only find it more difficult to hear in general, but they would also sometimes find it difficult to accurately pinpoint which direction the sound was coming from.
True
True (a)/False (b): Traumatic fracture of the ossicles that no longer couples movement of the tympanic membrane with movement of the oval window would affect hearing in that ear, but would not produce a complete loss of hearing in the affected ear.
True
True or False: Cone cells only respond to specific wavelengths of light, and the relative activation of each type of cone allows us to perceive all colors in the visual spectrum
True
You are working with a computer simulation of a spinal cord reflex. On your computer screen you can visualize the afferent neuron, the interneurons in the spinal cord, the efferent neurons, and the corticospinal neurons descending from the cortex and synapsing onto the interneurons and/or efferent neurons. You can also visualize the degree of muscle stimulation in the agonist and antagonist muscles, and the amplitude of movement from the reflex. True (a)/ False (b): In your simulation, you decrease the frequency of EPSPs from descending corticospinal neurons directly onto the efferent motor neurons to the antagonist muscle only (with no change to the EPSPs directly onto the efferent motor neurons to the agonist muscle). The expected outcome is an increase in the amplitude of the reflexive movement.
True
Which of the following are necessary prior to calcium release in a muscle cell? a. Action potential in the T-tubule. b. ATP binding to myosin head. c. Binding of an ion to troponin. d. All of the above. e. Only A and C.
a. Action potential in the T-tubule.
Which of the following are true of the parasympathetic nervous system. a. All parasympathetic neurons are cholinergic. b. The post-ganglionic parasympathetic neurons have muscarinic receptors on their dendrites and soma. c. The signal speed from the spinal cord to the target organ is slower in the parasympathetic nervous system than in the sympathetic nervous system. d. All of the above. e. Only A and C.
a. All parasympathetic neurons are cholinergic.
Thinking about the processes that lead to skeletal muscle contraction, which of the following accurately describes how calcium enters the cell? a. An action potential travels down the t-tubules and activates the voltage-gated DHP receptors, which open the mechanically gated Ryanodine channels, allowing calcium to be released from the sarcoplasmic reticulum b. An action potential travels down the t-tubules and activates ligand-gated DHP receptors, which open the mechanically gated Ryanodine channels, allowing calcium to be released from the sarcoplasmic reticulum c. Acetylcholine travels down the t-tubules and activates ligand-gated DHP receptors, which open the mechanically gated Ryanodine channels, allowing calcium to be released from the sarcoplasmic reticulum d. Acetylcholine travels down the t-tubules, binding to receptors that open calcium channels and allow calcium influx from the extracellular fluid
a. An action potential travels down the t-tubules and activates the voltage-gated DHP receptors, which open the mechanically gated Ryanodine channels, allowing calcium to be released from the sarcoplasmic reticulum
A toxin that binds to troponin C, and acts as an antagonist, has been injected into an experimental skeletal muscle fiber, and saturates all available binding sites. Which of the following is the expected outcome? a. Inability to generate forces in the muscle fiber b. Continuous myosin cross bridge cycling as long as there is available ATP c. Inability to generate an electrical signal along the muscle fiber d. Only A and B e. Only A and C
a. Inability to generate forces in the muscle fiber
How would cAMP concentration change when taking a PDE inhibitor as compared to not taking a PDE inhibitor? a. Increase in cAMP concentration b. Decrease in cAMP concentration c. No change in cAMP concentration
a. Increase in cAMP concentration
How does an increase in the frequency of stimulation at the neuromuscular junction support an increase in muscle force production? a. It increases the concentration of calcium inside the cell b. It decreases the concentration of calcium inside the cell c. It increases the rate the calcium ATPase pump moves calcium back into the Sarcoplasmic reticulum d. It creates higher amplitude action potentials down the t-tubules
a. It increases the concentration of calcium inside the cell
As we begin to produce more force of muscle contraction, how does the body recruit motor units? a. Motor units are recruited from small to large as we increase force of contraction b. Motor units are recruited from large to small as we increase force of contraction c. Motor units are recruited randomly as we increase force of contraction d. We always recruit all the motor units within a given muscle
a. Motor units are recruited from small to large as we increase force of contraction
Which of the following are examples of active transport. a. Na+ moving across the cell membrane due to the Na+/K+ ATPase pump. b. Cl- moving across the cell membrane through a ligand-gated channel. c. Oxygen moving across the cell membrane directly through the lipid bilayer. d. All of the above. e. Only A and C.
a. Na+ moving across the cell membrane due to the Na+/K+ ATPase pump.
Which of the following stimulate G proteins that lead to the utilization of cAMP as a second messenger? a. Odorants b. Tastants c. Light d. A and B e. A and C
a. Odorants
18. Which of the following are true regarding vision? a. Photons of light travel past the cells of the retina to reach the photoreceptors. b. The G protein transducin is activated directly by photons of light, and its Gα unit produces an activated (all trans) version of rhodopsin. c. A negative afterimage is produced when rhodopsin is still in its activated state, even though you have looked away from the light stimulus. d. All of the above. e. Only B and C.
a. Photons of light travel past the cells of the retina to reach the photoreceptors.
Beta blockers are a drug that decreases the ability for neurotransmitters to bind to Beta adrenergic receptors on the heart. Which branch of the autonomic nervous system is affected by these drugs, and what neurotransmitter is involved? a. Sympathetic, adrenaline b. Parasympathetic, adrenaline c. Sympathetic, acetylcholine d. Parasympathetic, acetycholine
a. Sympathetic, adrenaline
What is the most accurate description of a membrane potential? a. The voltage inside the membrane, relative to outside the membrane b. The chemical concentration inside the membrane, relative to outside the membrane c. The voltage outside the membrane, relative to inside the membraned. d. The chemical concentration outside the membrane, relative to inside the membranee. e. The pressure inside the membrane, relative to outside the membrane
a. The voltage inside the membrane, relative to outside the membrane
Thinking about cell to cell communication between pre and post synaptic neurons, identify whether each statement is TRUE or FALSE. True/False: Calcium ion influx at the axon terminal causes the release of acetylcholine into the synapse.
a. True
True/False: If an excitatory pre-synaptic neuron fires multiple times over a short period of time (high frequency), this can lead to temporal summation. a. True b. False
a. True
True/False: When an action potential reaches the axon terminal, it causes opening of voltage gated calcium channels. a. True b. False
a. True
Which of the following are true regarding auditory physiology? a. When the stereocilia of the hair cells are deflected such that all channels are open, there is potassium influx. b. When all channels are open, the cell becomes hyperpolarized. c. When the stereocilia are not being deflected (they are in the resting position), all ion channels are closed. d. Only B and C. e. None of the above.
a. When the stereocilia of the hair cells are deflected such that all channels are open, there is potassium influx.
The brain communicates the strength of a signal to the muscles by changing the ___________________ of action potentials. a. frequency b. amplitude c. duration d. direction
a. frequency
Describe the characteristics of a) a slow twitch muscle fiber and b) the motor unit it is a part of, which differentiate it from a fast twitch muscle fiber. a) Muscle fiber characteristics:__________________________ b) Motor unit characteristics:__________________________
a. lots of mitochondria, capillaries and myoglobin, aerobic, red b. smaller neuron, easier to reach threshold, fewer fibers/neuron
Name a physical and environmental condition that would lead to an increase in the speed of signal transmission along a neuron: a. Physical characteristic of neuron: __________________ b. Environmental condition: __________________
a. myelinated, large diameter; not lower threshold, not faster b. increased temperature
The rate of repolarization of a nerve cell action potential is likely to be slowed down (takes longer to repolarize) by which of the following? a. A drug that blocks the Na+ channels b. A drug that blocks the K+ channels c. A drug that significantly increases the concentration of K+ ions inside the cell d. Both A and B e. Both B and C
b. A drug that blocks the K+ channels
Which of the following would be an example of an inhibitory post synaptic potential? a. A signal that causes Na+ influx b. A signal that causes K+ efflux c. A signal that causes the membrane potential to become more positive d. Only A and C e. Only B and C
b. A signal that causes K+ efflux
In the lab, you experimented with stimulating motor neurons at various intensities, and observed the resultant M-waves. Based on what you saw and discussed in lab, which of the following statements is/are TRUE regarding motor neuron stimulation? a. If you continue to increase the stimulus intensity, but the M-wave amplitude eventually plateaus, you can conclude that the large motor units have fatigued b. If you stimulate a group of motor neurons, but the M-wave amplitude remains at zero, it is reasonable to conclude that the stimulus was not sufficient to cause the membrane potential in the motor neurons to reach the threshold necessary to produce action potentials. c. Increasing the frequency of neuron stimulation with a bar stimulus electrode has the same physiological effect on motor unit recruitment as increasing the intensity of neuron stimulation with the bar stimulus electrode. d. Only A and B
b. If you stimulate a group of motor neurons, but the M-wave amplitude remains at zero, it is reasonable to conclude that the stimulus was not sufficient to cause the membrane potential in the motor neurons to reach the threshold necessary to produce action potentials.
Which of the following are enzymes involved in the intracellular outcomes initiated by a G protein coupled receptor? a. Transducin b. Phosphodiesterase c. Retinal d. All of the above e. Only A and B
b. Phosphodiesterase
Which of the following accurately describe the Nernst equation value? a. The membrane potential at which the electrical and chemical gradients are both the largest. b. The membrane potential at which the electrical and chemical gradients are equal and opposite. c. The membrane potential at which the force of the combined gradients is the largest. d. The membrane potential at which all permeable ions no longer move across the membrane.
b. The membrane potential at which the electrical and chemical gradients are equal and opposite.
Which of the following best describes the "take home message" from Dr. Ramachandran's TedTalk regarding the likely reason that use of a mirror box has helped some patient's with phantom limb pain? a. The patient believes that their amputated arm has returned and can move, so they no longer feel pain. b. The visual input regarding the phantom limb moving again is so compelling that the brain creates a new neural pattern that no longer includes the perception of paralysis and pain. c. The neurons that connected the visual cortex and the motor cortex were initially damaged, and training with the mirror box helps those neurons to regrow.
b. The visual input regarding the phantom limb moving again is so compelling that the brain creates a new neural pattern that no longer includes the perception of paralysis and pain.
When contracted, the stapedius muscle and tympani muscle: a. amplify sound conduction b. attenuate sound conduction c. amplify sound frequency d. filter frequencies >100Hz
b. attenuate sound conduction
Which of the following would lead to a decrease in the strength of the post-synaptic graded potential in a neuron with excitatory cholinergic receptors? a. A competitive agonist for the acetylcholine at the synapse. b. A decrease in the activity of acetylcholinesterase at the synapse. c. A toxin that blocked calcium channels in the pre-synaptic membrane. d. All of the above. e. Only B and C
c. A toxin that blocked calcium channels in the pre-synaptic membrane.
Atropine is a drug that blocks muscarinic receptors in the body. Which of the following will experience some effect from this drug, specifically due to its effect on muscarinic receptors? a. Sympathetic nervous system b. Parasympathetic nervous system c. Both d. Neither
c. Both
Which of the following best describes why calcium must be present in the muscle cell for contraction to occur? a. Calcium is necessary for an action potential to occur. b. Without calcium, myosin cannot be released from the actin. c. Calcium binding to troponin leads to availability of actin binding sites.
c. Calcium binding to troponin leads to availability of actin binding sites.
If beta adrenergic receptor blockers were suddenly added to person's system at rest, what affect would you expect it to have on heart rate? a. No change b. Increase c. Decrease
c. Decrease
The nervous system typically uses which of the following to communicate the strength of a neuronal signal? a. Intensity b. Amplitude c. Frequency
c. Frequency
A Pacinian corpuscle is an example of a tactile sensory neuron with receptors in the skin. Where is the cell body for this neuron located? a. In the skin. b. Adjacent to the receptors. c. In or adjacent to the spinal cord. d. All of the above. e. Only A and B.
c. In or adjacent to the spinal cord.
Which of the following sensory receptors are connected to the largest, fastest (~120 m/sec), type I sensory neurons. a. Pain b. Temperature c. Muscle spindles. d. All of the above e. Only A and C.
c. Muscle spindles.
Phosphodiesterase (PDE) inhibitors are commonly used medications. PDE inhibitors block the action of the enzyme phosphodiesterase. Assuming it has no direct effects on other enzymes in the system, how would Adenylate Cyclase activity change when taking a PDE inhibitor, as compared to not taking a PDE inhibitor? a. Increase in Adenylate Cyclase activity b. Decrease in Adenylate Cyclase activity c. No Change in Adenylate Cyclase activity
c. No Change in Adenylate Cyclase activity
The Nernst Equation values, and relative concentrations for the imaginary ions in this scenario are as follows: W- = -80mV and has a higher concentration outside the cell. X+ = -30mV and has a higher concentration inside the cell. Q- = +70mV and has a higher concentration inside the cell. The resting membrane potential is -100mV, and threshold is -80mV. Which of the following ions would be flowing across the membrane to produce depolarization of the imaginary neuron from -80mV to +60mV? a. W- b. X+ c. Q- d. All of the above e. Only B and C
c. Q-
You are working in Dr. Dreyer's muscle physiology lab. He asks you to measure the length of the A-bands in a muscle sample. Which of the following are TRUE about A-bands? a. A-bands are the area of the sarcomere that contain only actin with no overlap of myosin b. A-bands are the area of the sarcomere that contain only myosin with no overlap of actin c. The length of the A-bands should stay the same, even when the sarcomere shortens d. Both B and C
c. The length of the A-bands should stay the same, even when the sarcomere shortens
What is the name of the second messenger involved in when the enzyme Adenylate Cyclase is activated? (abbreviations are fine)
cAMP
Ultimately, it is the number of _____________________ that dictate the amount of force being produced in a muscle cell, since this is what literally creates the physical force. _______________ increase with stimulus frequency.
cross bridges, cross bridges
Which of the following are agonists of muscarinic cholinergic receptors? a. Nicotine b. Muscarine c. Adrenaline d. All of the above e. Only A and B
d. All of the above
Which of the following are ways extracellular signaling molecules can cause intracellular effects? a. Extracellular signals activate a G-protein b. Extracellular ligands bind to a receptor and open an ion channel c. Extracellular signals travel across the cell membrane and activate an enzyme inside the cell d. All of the above e. Only A and B
d. All of the above
Which of the following is/are TRUE of the Na+/K+ ATPase pump? a. The Na+/K+ ATPase pump moves both Na+ out of the cell and K+ into the cell b. Pumping of Na+ and K+ against their concentration gradients helps to maintain a concentration gradient that supports influx of Na+ and efflux of K+ through their leak channels c. The Na+/K+ ATPase pump helps maintain resting membrane potential d. All of the above are TRUE e. Only B and C are TRUE
d. All of the above are TRUE
Which of the following is/are TRUE related to the anatomy of the axon and speed of transmission of an action potential along its axon? a. Nerves with a large axon diameter conduct signals faster than those with a small axon diameter b. Nerves that are myelinated conduct signals faster than those that are not myelinated c. Neurons conduct signals faster when heated d. All of the above are true e. Only b and c
d. All of the above are true
In which neurons is there a tonic signal present most (or all) of the time that can be increased or decreased, as opposed to neurons that typically send no signal, and are activated intermittently (like an on/off switch)? a. Autonomic neurons. b. Olfactory neurons. c. Auditory neurons. d. All of the above. e. Only A and C.
d. All of the above.
Under which of the following circumstances would you expect normal neuronal activity to be altered or affected? a. Malnutrition to the degree that the extracellular concentration of calcium is altered. b. Electrical input to the body that causes a change in the potential difference in voltage across the neuronal membrane. c. Change in the kinetic energy of the ions on either side of the neuronal membrane. d. All of the above. e. Only A and B.
d. All of the above.
Which of the following are involved in normal transmission of a neuronal signal from the brain to the skeletal muscles? a. Voltage-gated sodium ion channels. b. Ligand-gated ion channels. c. Nicotinic cholinergic channels. d. All of the above. e. Only A and C.
d. All of the above.
Which of the following could affect the amplitude of the depolarization peak of an action potential in a neuron? a. The duration of time the gated sodium ion channels remain open. b. The electrical gradient for sodium across the cell membrane. c. The chemical gradient for sodium across the cell membrane. d. All of the above. e. Only A and C.
d. All of the above.
Which of the following could impact the effectiveness of most G protein coupled receptors? a. The amount of extracellular ligand available to bind to the receptor. b. The amount of available intracellular GTP. c. The number and proximity of the intended intracellular target proteins/enzymes. d. All of the above. e. Only A and C.
d. All of the above.
Resting membrane potential of the cells is = -150mV Action potential peak = +120mV Information about the Ions: X-, higher concentration inside cell, Nernst potential = +135mV Y+, higher concentration inside cell, Nernst potential = -100mV Z+, higher concentration outside cell, Nernst potential = +380mV. You are investigating a tissue sample that includes strange, previously unknown, charged ions that appear to move across the neuron membrane in the same way that ions move across human neuron cell membranes. Using the information provided about the strange ions, and applying your knowledge of human action potentials, answer the following questions. -Opening of which ion channel could cause hyperpolarization of the cell membrane beyond normal resting membrane potential? a. Opening of X- ion channels could cause hyperpolarization b. Opening of Y+ ion channels could cause hyperpolarization c. Opening of Z+ ion channels could cause hyperpolarization d. None of the above would cause hyperpolarization
d. None of the above would cause hyperpolarization
Which of the following could lead to an increase in the likelihood of the postsynaptic neuron producing an action potential? a. A drug that interfered with the breakdown of acetylcholine b. A drug that competed with acetylcholine at the postsynaptic receptor (but did not cause the receptor to be activated) c. A drug that caused more acetylcholine to be released from the presynaptic neuron d. Only A and C e. Only B and C
d. Only A and C
Which of the following is true of cross bridge cycling? a. Rigor state is tight binding between tropomyosin and actin b. ATP binding to myosin head causes actin and myosin to dissociate c. Energy released from the breakdown of ATP to ADP and Pi causes the myosin head to move into the cocked position d. A and B e. B and C
e. B and C
Consider a cell that has a higher concentration of ion Z- outside the cell. This ion has a negative charge. Which of the following are possible Nernst Potentials for this ion? a. -70mV b. -30mV c. +70mV d. Any of these are possible Nernst Potentials for ion Z- e. Both A and B are possible Nernst Potentials for ion Z-
e. Both A and B are possible Nernst Potentials for ion Z-
Resting membrane potential of the cells is = -150mV Action potential peak = +120mV Information about the Ions: X-, higher concentration inside cell, Nernst potential = +135mV Y+, higher concentration inside cell, Nernst potential = -100mV Z+, higher concentration outside cell, Nernst potential = +380mV. You are investigating a tissue sample that includes strange, previously unknown, charged ions that appear to move across the neuron membrane in the same way that ions move across human neuron cell membranes. Using the information provided about the strange ions, and applying your knowledge of human action potentials, answer the following questions. -Opening of which ion channel could cause depolarization of the cell membrane? a. Opening of X- ion channels could cause depolarization b. Opening of Y+ ion channels could cause depolarization c. Opening of Z+ ion channels could cause depolarization d. None of the above would cause depolarization e. Both A and C
e. Both A and C
Imagine a condition in which the number of functioning receptors on the dendrites and soma of a neuron have decreased due to damage. Which of the following treatment options would improve the transmission of the signal between the excitatory presynaptic terminals and the damaged post-synaptic neuron (i.e.: produce a larger graded potential in the damaged neuron)? a. A treatment that increased the number of calcium channels that open following each action potential (in the presynaptic axon terminals) b. A treatment that decreased activity of the enzyme that breaks down the neurotransmitter c. Infusion of a drug into the synaptic spaces that is an antagonist for the neurotransmitter d. All of the above e. Only A and B
e. Only A and B
Which of the following are accurate descriptions of an Inhibitory Post Synaptic Potential (IPSP)? a. Can be produced by an ion channel that allows for K+ efflux. b. Can be produced by an ion channel that allows for Cl- influx. c. One IPSP will lead to a sub-threshold stimulus at the axon hillock, regardless of the number of EPSPs that occur. d. All of the above. e. Only A and B.
e. Only A and B.
A new drug eliminates the hyperpolarization phase of neuronal action potentials. Which of the following is plausible regarding this situation? a. There would be no relative refractory period b. The drug causes voltage gated Na+ channels to be delayed in opening c. The drug causes voltage gated K+ channels to close more quickly d. All of the above e. Only A and C
e. Only A and C
How is ATP involved in cross-bridge cycling of skeletal muscle? a. When ATP binds to the myosin heads, this causes the myosin head to detach from the actin binding site b. When ATP is broken down into ADP and Pi, the energy released causes the power stroke and shortening the sarcomere c. When ATP is broken down into ADP and Pi, the energy released causes the re-cocking of the myosin heads back to their 90 degree position d. Only A and B e. Only A and C
e. Only A and C
Which of the following accurately describes what happens when G protein coupled receptors (GPCRs) are activated? a. When the GPCR is activated, GTP replaces the bound GDP b. GPCRs always open ion channels c. The Gα disassociates from the beta/gamma unit when GTP is bound to it d. All of the above e. Only A and C
e. Only A and C
Consider the similarities and differences of all the senses that we have discussed this term, and select only accurate statements from the following choices. a. Every sense requires a specialized receptor that responds to the particular stimulus involved, and a receptive cell to provide a mechanism to transduce the unique stimulus into the language of neurons (neurotransmitters and/or action potentials). b. All the special senses use a G protein coupled receptor in at least one aspect of their activation process. c. Neuronal information regarding each of the senses is eventually processed in a specific area of the cortex, which leads to perception of the stimulus. d. All of the above. e. Only A and C.
e. Only A and C.
The terminal cisternae are a part of which of the following? a. Sarcoplasmic reticulum. b. T-tubule. c. "The Triad". d. All of the above. e. Only A and C.
e. Only A and C.
Think about action potentials traveling along the axon of a nerve cell, indicate which of the following is/are TRUE. a. When threshold is reached at the axon hillock, a single action potential travels down the length of the neuron to the axon terminal b. When threshold is reached at the axon hillock, multiple action potentials occur in local areas along the length of the axon to carry the signal to the axon terminal c. Refractory periods support the one way movement of an action potential down the axon when the action potential is initiated from the axon hillock d. Only A and C e. Only B and C
e. Only B and C
Which of the following describe how an electrical signal gets transmitted from one end of the neuron to the other? a. Action potentials travel through the cell body to the axon hillock b. Graded potentials travel through the cell body to the axon hillock c. If the electrical signal at the axon hillock is above threshold, an action potential is sent down the length of the axon to the axon terminal d. Only A and C e. Only B and C
e. Only B and C
During the depolarization phase of an action potential in a nerve cell, which of the following is/are TRUE? a. The membrane potential is becoming more negative b. The Na+ activation gates are open c. The Na+ inactivation gates are open d. All of the above are TRUE e. Only B and C are TRUE
e. Only B and C are TRUE
In the last physiology lab, you stared at a card with four colors on it for about one minute, and then you looked at a white surface. Focusing specifically on the change that occurred related to the blue dot, which of the following below is an accurate description of the underlying physiological mechanisms, or of the experience itself? a. Where the blue dot had been originally, you should have perceived a green after-image. b. You saw the complimentary color after-image, in part, due to fatigue of the blue cones. c. The after-image was the complimentary color because looking at a white surface typically activates all the cones, but only the non-fatigued cones could send a signal. d. All of the above. e. Only B and C.
e. Only B and C.
Which of the following are accurate regarding action potentials in a neuron? a. In order for sodium influx to stop, both the activation and inactivation gates must be closed. b. Each section of membrane undergoes a relative refractory period during which it is possible to depolarize the membrane again, but only if the intensity of the signal is great enough. c. The neuron membrane is most permeable to sodium ions at the same time that the depolarization peak occurs. d. All of the above. e. Only B and C.
e. Only B and C.
Which of the following are true regarding the sense of taste? a. The papillae (fungiform, vallate, filiform) are also known as taste buds. b. ATP is believed to be the neurotransmitter released by some taste cells onto the gustatory sensory neurons. c. Intracellular Ca2+ released during taste cell activation serves as a ligand to open ion channels. d. All of the above. e. Only B and C.
e. Only B and C.
Resting membrane potential of the cells is = -150mV Action potential peak = +120mV Information about the Ions: X-, higher concentration inside cell, Nernst potential = +135mV Y+, higher concentration inside cell, Nernst potential = -100mV Z+, higher concentration outside cell, Nernst potential = +380mV. You are investigating a tissue sample that includes strange, previously unknown, charged ions that appear to move across the neuron membrane in the same way that ions move across human neuron cell membranes. Using the information provided about the strange ions, and applying your knowledge of human action potentials, answer the following questions. When the cell membrane is at a membrane potential of +100mV, the electrochemical gradients of which ions would favor efflux? a. X- ion b. Y+ ion c. Z+ ion d. None of the ions e. Only X- ion and Y+ ion
e. Only X- ion and Y+ ion-
What specifically allows for the transduction of a mechanical stimulus into an electrical signal in auditory physiology?
hair cells, stereocilia, mechanoreceptors
List two factors that affect the speed of a sensory-motor reflex:
neuron type/size/speed,distance traveled, number of synapses, complexity of receptor
When oxygen moves across the cell membrane down its gradient, it does not require a protein to travel through. What is the best term used to describe this type of movement across the cell membrane? (be specific)
passive diffusion
The scala vestibuli and scala tympani contain ______ (perilymph), which has a high concentration of ___ [Na+] ions. The scala media contains _____ (endolymph), which has a high concentration of ____ ([K+])ions. The scala media is bordered by the __________ (basilar membrane), which is the site of the _______ (Organ of Corti).
perilymph; [Na+] ions; endolymph;[K+] ions; basilar membrane; organ of corti
If the charge of an ion is positive and it has a greater concentration outside a cell, the Nernst potential for that ion is ___________.
positive
Bipolar cells in the retina have receptors that bind to synaptic glutamate, which is released from _________________. Bipolar cells release their neurotransmitters onto ___________________.
rods/cones/photoreceptors; ganglion cells
Even a small quantity of odorant can cause a big enough response to elicit depolarization beyond the resting membrane potential in an olfactory receptor cell. What proteins or molecules allow for this signal amplification?
second messengers, adenylate cyclase, cAMP