Sherwood Ch 4, Physiology

What type of transporter refills the synaptic vesicle with neurotransmitter? How is it different from the SGLT transporter that moves glucose from the digestive lumen into intestinal epithelial cells?

(H+/neurotransmitter) secondary active transporter. It is an antiporter vs SGLT is a symporter (movement of nt is opposite the movement of driving ion whereas movement of glu is same direction of driving ion)

Neuron A is excitatory to neuron B. Describe three ways that the nervous system might prevent neuron B from experiencing an action potential.

(1) Neuron A is not stimulated; therefore, it will not generate EPSPs on neuron B. (2) Neuron A is actively inhibited by the formation of IPSPs on its dendrites and cell body; therefore, action potentials are not generated at A's axon hillock. (3) Neuron A sends an impulse along its axon, but another neuron inhibits the release of neurotransmitter from A's axon terminal; this is presynaptic inhibition and no EPSPs are generated on B. PTS: 1 DIF: Evaluation

Select the first step for synaptic signaling after the action potential arrives at the axon terminal of a synaptic neuron

Calcium influx in the synaptic knob

How is cardiac muscle similar to smooth muscle but different from Skeletal muscle with regard to Ca use during contraction.

Cardiac muscle is similar to smooth muscle in that it requires entry of extracellular Ca to stimulate more Ca release from SR and initiate contraction. Whereas Skeletal muscle does not require extracellular Ca entry into the cell for contraction.

Action potentials are generated when voltage-gated sodium and potassium channels are activated. Voltage-gated sodium channels have activation and inactivation gates. a. Which gate is primarily responsible for the absolute refractory period during an action potential? Does the opening or closing of this gate lead to the absolute refractory period? b. At what point during an action potential is that gate triggered?

Closing of the inactivation gate 14b 1pt: At threshold

Neuropeptides a. are sometimes co-secreted along with classical neurotransmitters b. are synthesized in the cytosol of the axon terminal c. act at the subsynaptic membrane of the postsynaptic neuron d. act slowly to bring about an IPSP or EPSP e. are larger molecules than classical neurotransmitters

ANS: A PTS: 1 DIF: Knowledge

Permeability of which ion is affected by a positive feedback mechanism once threshold is reached? a. sodium b. potassium c. calcium d. chloride e. protein

ANS: A PTS: 1 DIF: Knowledge

Presynaptic facilitation results from a. alteration of calcium permeability b. continued generation of EPSPs c. neuromodulator effects d. increased neurotransmitter production e. none of the above

ANS: A PTS: 1 DIF: Knowledge

Temporal summation on a postsynaptic neuron would occur when a. a single presynaptic input causes two EPSPs to develop in rapid succession b. an EPSP and an IPSP occur simultaneously and cancel each other out c. two EPSPs develop simultaneously from different presynaptic inputs d. two action potentials from two presynaptic inputs causes two action potentials to develop e. none of the above take place

ANS: A PTS: 1 DIF: Knowledge

The trigger zone of a neuron a. is located at the axon hillock b. is located in the axon terminal c. contains only chemically gated channels d. conducts graded potentials to the axon e. causes action potentials to move toward the cell body and dendrites

ANS: A PTS: 1 DIF: Knowledge

When is a plasma membrane more permeable to K+ than to Na+? a. During the resting potential b. During the rising phase of an action potential c. During the rising phase of a graded potential d. Both a and b e. Both b and c

ANS: A PTS: 1 DIF: Knowledge

Binding of an excitatory neurotransmitter to a postsynaptic neuron causes a. voltage-gated Na+ channels open b. voltage-gated K+ channels open c. chemically-gated Na+ channels open d. voltage-gated Cl- channels open e. chemically-gated Cl- channels open

ANS: C PTS: 1 DIF: Comprehension

Saltatory conduction a. occurs in unmyelinated nerve fibers b. is slower than contiguous conduction because myelin acts as an insulator to slow the impulse c. involves the impulse jumping from one node of Ranvier to the adjacent node d. refers to the action potential spreading from one Schwann cell to the adjacent Schwann cell e. occurs along dendrites and axons of certain neurons

ANS: C PTS: 1 DIF: Comprehension

The negative charge established along the cytosolic border a nerve cell membrane is due to a. movement of sodium ions into the cell b. movement of proteins out of the cell c. higher permeability of K+ relative to Na+ d. movement of proteins through membrane channels e. both b and d

ANS: C PTS: 1 DIF: Comprehension

A threshold potential is a. the potential achieved when two opposing forces acting upon an ion (concentration and electrical gradients) achieve a state of equilibrium b. the peak potential achieved during an action potential c. the point at which there is an explosive increase in Na+ or Ca2+ permeability d. the potential at which K+ permeability increases e. always a positive potential

ANS: C PTS: 1 DIF: Knowledge

All of the following may be considered second messengers except a. inositol triphosphate b. calcium ions c. phosphodiesterase d. cyclic AMP e. diacylglycerol

ANS: C PTS: 1 DIF: Knowledge

Local current flow a. occurs only on dendrites of neurons b. causes impulses to move from the axon hillock toward the neuron's cell body c. involves current flowing between active and adjacent inactive areas, thereby bringing the inactive areas to threshold d. occurs only on axons of neurons e. does not occur on all excitable membranes

ANS: C PTS: 1 DIF: Knowledge

Tetanus toxin a. binds with glycine receptors, thus blocking the action of this inhibitory neurotransmitter b. destroys dopamine in the region of the brain involved in controlling complex movements c. prevents the release of GABA that inhibits neurons that innervate skeletal muscle cells d. promotes presynaptic facilitation e. causes IPSPs to occur on skeletal muscle cell membranes

ANS: C PTS: 1 DIF: Knowledge

The nucleus of a neuron is housed in the a. axon b. axon hillock c. cell body d. collaterals e. dendrites

ANS: C PTS: 1 DIF: Knowledge

When chemically-gated Na+ channels open, the membrane a. hyperpolarizes b. repolarizes c. depolarizes d. becomes more negative e. is inhibited

ANS: C PTS: 1 DIF: Knowledge

Which statement about graded potentials is false? a. They are decremental. b. They travel only short distances. c. They are self-propagating. d. They may contribute to the development of an action potential. e. They travel in both directions along the membrane.

ANS: C PTS: 1 DIF: Knowledge

Which statement is incorrect? a. A local current can occur in myelinated nerve fibers b. A local current flow from an active to an adjacent inactive area decreases the potential in the inactive area to threshold c. Contiguous conduction occurs along Schwann cells on myelinated nerve fibers d. Saltatory conduction is faster than contiguous conduction e. A local current can occur in myelinated nerve fibers

ANS: C PTS: 1 DIF: Knowledge

With presynaptic inhibition, a. an IPSP occurs on the postsynaptic cell b. all excitatory information being fed into the cell is prevented c. the release of excitatory neurotransmitter from a specific presynaptic excitatory input is depressed. d. at least two of the above occur. e. none of the above occur.

ANS: C PTS: 1 DIF: Knowledge

An action potential in a presynaptic neuron induces opening of voltage-gated ____________________ channels in the synaptic knob, which triggers exocytosis of synaptic vesicles.

ANS: Ca++ PTS: 1 DIF: Knowledge

If neuron X causes hyperpolarization of neuron Z but neuron Y causes depolarization of neuron Z, what change would you expect in neuron Z if it is stimulated by both X and Y simultaneously? a. a significant increase in membrane potential b. a significant decrease in membrane potential c. temporal summation leading to an impulse on Z d. simultaneous influx and efflux of cations or simultaneous influx of cations and efflux of anions e. an increase in the resting membrane potential

ANS: D PTS: 1 DIF: Analysis

1. A change in a membrane potential from +30 mV to -70 mV is an example of a. depolarization b. hyperpolarization c. polarization d. repolarization e. zero potential

ANS: D PTS: 1 DIF: Comprehension

Select the last step for synaptic signaling when the action potential arrives at the axon terminal of a presynaptic neuron. a. A neurotransmitter is released by exocytosis. b. Calcium flows in the synaptic knob. c. The neurotransmitter combines with a protein receptor on the subsynaptic membrane. d. The permeability is altered in a postsynaptic neuron. e. Sodium influx occurs at the axon terminals

ANS: D PTS: 1 DIF: Comprehension

Because of the presence of both activation and inactivation gates, voltage-gated Na+ channels can a. be closed but capable of opening b. be activated c. be closed and not capable of opening d. exhibit all of the above events e. exhibit only the a and b events

ANS: D PTS: 1 DIF: Knowledge

In divergence, a. many presynaptic neurons synapse with one postsynaptic cell b. one dendrite contacts many presynaptic neurons c. action potentials initiated in the axon diminish as they spread to axon terminals d. one axon synapses with many other cells e. many axons spread out from one cell body

ANS: D PTS: 1 DIF: Knowledge

Neuromodulators a. bind to receptors at synapses b. contribute directly to EPSPs c. contribute directly to IPSPs d. may influence neurotransmitter production e. speed up contiguous impulse conduction

ANS: D PTS: 1 DIF: Knowledge

Select the neuropeptide. a. acetylcholine b. dopamine c. epinephrine d. cholecystokinin e. glycine

ANS: D PTS: 1 DIF: Knowledge

The relative refractory period occurs after the action potential is complete because of a. the lingering inactivation of the voltage-gated Na+ channels b. the slowness of the voltage-gated K+ channels c. the action of the sodium-potassium pumps d. both a and b e. both b and c

ANS: D PTS: 1 DIF: Knowledge

When comparing saltatory conduction to contiguous conduction, saltatory conduction a. is the only method that occurs along both dendrites and axons b. is the only method that utilizes a positive feedback cycle c. requires more Na+-K+ activity after repolarization is complete d. causes the loss of fewer K+ ions during repolarization e. occurs along unmyelinated axons

ANS: D PTS: 1 DIF: Knowledge

Which of the following is least related to a neuromodulator? a. axonal transport b. dense-core vesicle c. cholecystokinin d. synaptic vesicle e. neuropeptide

ANS: D PTS: 1 DIF: Knowledge

Which of the following is/are found in all cells of excitable and nonexcitable tissues? a. a threshold potential b. a resting membrane potential c. gated ion channels d. all of the above characteristics e. mechanically-gated channels

ANS: D PTS: 1 DIF: Knowledge

Which statement about a graded potential is false? a. It can be a depolarization. b. It can be a hyperpolarization. c. It can be summated. d. It has a refractory period. e. It occurs in a specialized area of the membrane.

ANS: D PTS: 1 DIF: Knowledge

Which statement is not accurate about the absolute refractory period? a. Another stimulus, regardless of its strength, cannot initiate another action potential during this period b. During this period, voltage-gated Na+ channels open, then close but are inactivated c. Immediately following this period, the membrane can experience another action potential if the stimulus is strong enough d. This period occurs during the after hyperpolarization phase of the action potential e. This period ensures a unidirectional spread of the action potential down a nerve fiber

ANS: D PTS: 1 DIF: Knowledge

If an excitatory neuron and an inhibitory neuron both stimulate the same postsynaptic neuron simultaneously, what can you know for sure is happening in the postsynaptic neuron? a. it would likely reach threshold b. its permeability to cations and anions would decrease c. its resting membrane potential would increase d. it would be experiencing temporal summation e. increased permeability to cations

ANS: E PTS: 1 DIF: Analysis

If neuron X is repeatedly stimulating neuron Z with an excitatory neurotransmitter, then a. several simultaneous action potentials might be initiated on neuron Z b. the membrane potential on neuron Z would increase c. spatial summation would be occurring on neuron Z d. the postsynaptic neuron in this situation would have to reach threshold voltage e. none of the above would have to occur

ANS: E PTS: 1 DIF: Application

Neuron A and neuron B release a minimal amount of neurotransmitter simultaneously onto neuron C, causing neuron C to experience an action potential. This is an example of a. temporal summation b. spatial summation c. convergence d. both a and c e. both b and c

ANS: E PTS: 1 DIF: Application

At the peak of an action potential, a. the diffusion of Na+ through voltage-gated channels ceases b. the concentration gradient for K+ promotes the movement of this ion out of the cell c. K+ permeability greatly increases d. the electrical gradient promotes the diffusion of K+ out of the cell e. all of the above are true

ANS: E PTS: 1 DIF: Comprehension

Select the first step for synaptic signaling when the action potential arrives at the axon terminal of a presynaptic neuron. a. A neurotransmitter is released by exocytosis. b. Calcium flows into the synaptic knob. c. The neurotransmitter combines with a protein receptor on the subsynaptic membrane. d. The permeability is altered in a postsynaptic neuron. e. The axon terminal depolarizes.

ANS: E PTS: 1 DIF: Comprehension

T/F Divergence refers to the neuronal arrangement wherein the dendrites diverge to synapse with as many presynaptic inputs as possible.

ANS: F PTS: 1 DIF: Knowledge

T/F During the relative refractory period, a neuron can experience hyperpolarization but not depolarization.

ANS: F PTS: 1 DIF: Knowledge

T/F For graded potentials, the magnitude of triggering is coded for in frequency rather than amplitude of depolarizations.

ANS: F PTS: 1 DIF: Knowledge

T/F Multiple sclerosis develops from a buildup of myelin of a neuron.

ANS: F PTS: 1 DIF: Knowledge

T/F Myelinated fibers throughout the nervous system can regenerate when cut, but unmyelinated fibers cannot regenerate.

ANS: F PTS: 1 DIF: Knowledge

T/F Nerve fiber is another name for a dendrite on a neuron.

ANS: F PTS: 1 DIF: Knowledge

T/F Oligodendrocytes are specialized to conduct electrical impulses to neurons.

ANS: F PTS: 1 DIF: Knowledge

T/F Oligodendrocytes form a regeneration tube to guide a regenerating nerve fiber to its proper destination.

ANS: F PTS: 1 DIF: Knowledge

T/F Only neurons and muscle cells establish resting membrane potentials.

ANS: F PTS: 1 DIF: Knowledge

T/F Preprohormones give rise to lipophilic hormones.

ANS: F PTS: 1 DIF: Knowledge

T/F The conduction velocity of a nerve impulse is slower in myelinated fibers than in unmyelinated fibers because myelin acts as an insulator that slows down the flow of current.

ANS: F PTS: 1 DIF: Knowledge

T/F The myelin covering the axon promotes the leakage of ions from an axon, but it promotes conservation of ATP in the neuron.

ANS: F PTS: 1 DIF: Knowledge

T/F The nodes of Ranvier are Schwann cells or oligodendrocytes that wrap themselves "jelly roll fashion" around the axon.

ANS: F PTS: 1 DIF: Knowledge

T/F Threshold potential is the peak potential achieved during an action potential.

ANS: F PTS: 1 DIF: Knowledge

T/F Thyroid hormone is derived from an amino acid, which makes it soluble in water and able to utilize a second messenger system.

ANS: F PTS: 1 DIF: Knowledge

At the end of repolarization, the newly opened channels for ____________________ ions close.

ANS: K+ PTS: 1 DIF: Knowledge

Opening a chemically-gated ____________________ channel or ____________________ channel will increase the membrane potential of a plasma membrane.

ANS: K+, Cl- PTS: 1 DIF: Comprehension

Opening channels that allow ____________________ ions or ____________________ ions result in depolarization of the plasma membrane.

ANS: Na+, Ca2+ PTS: 1 DIF: Comprehension

____________________ are released into the blood by neurosecretory neurons.

ANS: Neurohormones PTS: 1 DIF: Knowledge

____________________ are chemical messengers that bind to neuronal receptors at nonsynaptic sites and alter the effectiveness of ongoing synaptic activity.

ANS: Neuromodulators PTS: 1 DIF: Knowledge

____________________ are chemical messengers that do not cause the formation of EPSPs or IPSPs but rather bring about long-term changes that depress or enhance the action of the synapse.

ANS: Neuromodulators PTS: 1 DIF: Knowledge

____________________ move through the axon before being released from the synaptic knob and then bind to nonsynaptic receptors; whereas, ____________________ are made in the cytosol of the synaptic knob and after their release bind to subsynaptic receptors.

ANS: Neuromodulators, neurotransmitters PTS: 1 DIF: Knowledge

____________________ are local chemical messengers that exert an effect only on neighboring cells in the immediate environment.

ANS: Paracrines PTS: 1 DIF: Knowledge

____________________ is the hindrance to electrical charge movement.

ANS: Resistance PTS: 1 DIF: Knowledge

____________________ cells form myelin around neurons in the PNS, whereas ____________________ form myelin around neurons in the CNS.

ANS: Schwann, oligodendrocytes PTS: 1 DIF: Knowledge

T/F A balance of IPSPs and EPSPs will negate each other so that the grand postsynaptic potential is essentially unaltered.

ANS: T PTS: 1 DIF: Comprehension

T/F A single neuron may be presynaptic to one group of neurons and postsynaptic to another group of neurons.

ANS: T PTS: 1 DIF: Comprehension

T/F Adenylyl cyclase and diacylglycerol are more associated with hydrophilic hormones than with lipophilic hormones.

ANS: T PTS: 1 DIF: Comprehension

T/F Amplification is more closely associated with hydrophilic hormones than with lipophilic hormones.

ANS: T PTS: 1 DIF: Comprehension

T/F Cholera toxin is more disruptive to the action of hydrophilic hormones than to the action of lipophilic hormones.

ANS: T PTS: 1 DIF: Comprehension

T/F G proteins in the plasma membrane of certain cells may become activated in response to the binding of water-soluble hormones, whereas protein phosphatases are continuously active in these cells.

ANS: T PTS: 1 DIF: Comprehension

T/F Increased permeability of the postsynaptic cell to Cl- lessens the likelihood that the postsynaptic cell will undergo an action potential.

ANS: T PTS: 1 DIF: Comprehension

T/F The grand postsynaptic potential depends on the sum of activity of the presynaptic inputs.

ANS: T PTS: 1 DIF: Comprehension

T/F The refractory period prevents action potentials from spreading back over the part of the membrane where the impulse has just passed.

ANS: T PTS: 1 DIF: Comprehension

T/F cAMP and phospholipase are more closely associated with the action of water-soluble hormones than with the action of lipid-soluble hormones.

ANS: T PTS: 1 DIF: Comprehension

T/F Action potentials are initiated at the axon hillock region because it has the lowest threshold voltage.

ANS: T PTS: 1 DIF: Knowledge

T/F An unmyelinated fiber with a large diameter can conduct action potentials more rapidly than an unmyelinated fiber with a smaller diameter.

ANS: T PTS: 1 DIF: Knowledge

T/F Classical neurotransmitters and neuropeptides are sometimes co-secreted from the same axon terminal.

ANS: T PTS: 1 DIF: Knowledge

T/F During the absolute refractory period, the voltage-gated Na+ channels are not capable of opening again in response to another triggering event.

ANS: T PTS: 1 DIF: Knowledge

T/F During the resting potential, the membrane is more permeable to potassium ions than to sodium ions.

ANS: T PTS: 1 DIF: Knowledge

T/F In a graded potential, the direction of current flow is designated by the movement of positive charges.

ANS: T PTS: 1 DIF: Knowledge

T/F Lipophilic hormones bind to hormone response elements on DNA, which then initiates steps in the formation of new protein molecules.

ANS: T PTS: 1 DIF: Knowledge

T/F Local current flows locally between active and adjacent inactive areas of the cell membrane, thereby decreasing the potential in the inactive area to threshold.

ANS: T PTS: 1 DIF: Knowledge

T/F Multiple sclerosis is an autoimmune disease in which the body's defense system erroneously attacks the myelin sheath surrounding myelinated nerve fibers.

ANS: T PTS: 1 DIF: Knowledge

T/F Schwann cells promote axonal growth, while oligodendrocytes inhibit it.

ANS: T PTS: 1 DIF: Knowledge

T/F The Na+ and K+ channels that open and close during an action potential are voltage-gated channels.

ANS: T PTS: 1 DIF: Knowledge

T/F The diffusion of potassium ions reestablishes the resting membrane potential in a neuron immediately after it develops an action potential.

ANS: T PTS: 1 DIF: Knowledge

T/F The myelin on a myelinated fiber in the peripheral nervous system is part of Schwann cells wrapped around the axon.

ANS: T PTS: 1 DIF: Knowledge

T/F The passive current flow of a graded potential fades quickly.

ANS: T PTS: 1 DIF: Knowledge

T/F The refractory period limits the frequency of action potentials.

ANS: T PTS: 1 DIF: Knowledge

____________________-soluble hormones must use ____________________ systems to exert their effects on target cells.

ANS: Water, second-messenger PTS: 1 DIF: Comprehension

The longest part of a typical neuron is the ____________________.

ANS: axon or nerve fiber PTS: 1 DIF: Knowledge

The ____________________ or ____________________ of a neuron is a single, elongated tubular process that conducts action potentials away from the cell body and eventually terminates at other cells.

ANS: axon, nerve fiber PTS: 1 DIF: Knowledge

____________________ is a second messenger formed when a membrane enzyme called a cyclase becomes activated by a G protein.

ANS: cAMP PTS: 1 DIF: Knowledge

Axon terminals possess ____________________ voltage-gated channels that when operational induce neurotransmitter release.

ANS: calcium PTS: 1 DIF: Knowledge

A plasma membrane is polarized if it separates particles with an opposite ____________________.

ANS: charge PTS: 1 DIF: Knowledge

For a neuron, the axon is its _______ zone and an axon terminal is its ______ zone.

ANS: conducting, output PTS: 1 DIF: Knowledge

The neuronal relationship where many presynaptic cells terminate on a single postsynaptic cell is called ____________________.

ANS: convergence PTS: 1 DIF: Knowledge

An increase in the size of the ____________________ of a nerve fiber, along with the amount of ____________________ around the fiber both increase its rate of conduction.

ANS: diameter, myelin PTS: 1 DIF: Knowledge

The neuronal relationship where a single presynaptic cell branches to terminate on many other cells is called ____________________.

ANS: divergence PTS: 1 DIF: Knowledge

In a second messenger system, the first messenger is the __________.

ANS: hormone PTS: 1 DIF: Knowledge

The chemical called ____________________ along axons reduces resistance and, hence, increases impulse velocity.

ANS: myelin PTS: 1 DIF: Knowledge

During the resting membrane potential, the inside of a neuron has a net ____________________ charge.

ANS: negative PTS: 1 DIF: Knowledge

A single nerve cell, also called a ____________________, typically consists of the following three basic parts: ____________________, ____________________, and ____________________.

ANS: neuron, cell body, dendrites, axon PTS: 1 DIF: Knowledge

Schwann cells stimulate the formation of a(n) ____________________ tube to rebuild damaged neurons.

ANS: regeneration PTS: 1 DIF: Knowledge

A neuron starts to depolarize when _________________ ions move into the cell.

ANS: sodium PTS: 1 DIF: Comprehension

When EPSPs occurring simultaneously from two different presynaptic inputs add together or sum to bring the postsynaptic cell to threshold, it is called ____________________ summation.

ANS: spatial PTS: 1 DIF: Knowledge

One presynaptic neuron can only produce ____________________ summation on a postsynaptic neuron.

ANS: temporal PTS: 1 DIF: Comprehension

When EPSPs originating from a single presynaptic input occur so close together in time that they add together or sum, thereby bringing the postsynaptic cell to threshold, it is called ____________________ summation.

ANS: temporal PTS: 1 DIF: Knowledge

At ____________________ potential, typically around -55 mv, rapid depolarization occurs.

ANS: threshold PTS: 1 DIF: Knowledge

The process by which incoming signals are conveyed into a target cell, where they are transformed into a certain cellular response is called signal _________.

ANS: transduction PTS: 1 DIF: Knowledge

Addictive drugs such as cocaine enhance the brains reward system response. How does cocaine affect the level of dopamine in the synapse AND what is its mechanism of action?

Increases. Blocking the NSS/DAT and thereby preventing reuptake of dopamine in the synaptic knob/terminal.

Glomerular Filtration Rate (GFR)

Influenced by two factors 1.Net filtration pressure Hydrostatic pressure -colloid osmotic pressure -fluid pressureGlomerular capillary blood pressure is the major force that causes glomerular filtration GFR = Kf×net filtration pressure

Kidneys vs the lungs

The Kidneys(urinary system) are used to regulate levels of HCO3-in the blood The Lungs(respiratory system) are used to regulate levels of CO2in blood

during the resting potential

Voltage gated Na+ and Chl channels have difficulty moving across; K+ can move easily, A- cannot move across 3 Na+ out: 2 K+ in (-70 mV)

Assume that a hypothetical neuron has three presynaptic inputs: A and B are excitatory, and C is inhibitory. Indicate which of the following changes will take place. a. no change in potential of the postsynaptic cell b. spatial summation c. temporal summation What would occur if both presynaptic neurons A and C were fired simultaneously?

a

Choose the match for each substance listed. a. covering on the axon b. second messenger c. branching process from a cell body d. impulse-conducting region e. junction between neurons f. neurotransmitter Myelin

a

Indicate the direction that the force in question tends to move the involved ion under the stated conditions by writing the appropriate letter in the blank, using the following answer code: a. tends to move the involved ion out of the cell b. tends to move the involved ion into the cell Concentration gradient for K+ at the end of an action potential

a

Indicate the direction that the force in question tends to move the involved ion under the stated conditions by writing the appropriate letter in the blank, using the following answer code: a. tends to move the involved ion out of the cell b. tends to move the involved ion into the cell Concentration gradient for K+ at the peak of an action potential

a

Indicate the direction that the force in question tends to move the involved ion under the stated conditions by writing the appropriate letter in the blank, using the following answer code: a. tends to move the involved ion out of the cell b. tends to move the involved ion into the cell Electrical gradient for K+ at the peak of an action potential

a

Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. K+ concentration in the neuron's cytosol immediately before an action potential B. K+ concentration in the neuron's cytosol immediately following an action potential

a

Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Na+ concentration in the extracellular fluid B. Na+ concentration in the neuron's cytosol immediately following an action potential

a

Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Neuron's permeability to Na+ during the rising phase of an action potential B. Neuron's permeability to K+ during the rising phase of an action potential

a

Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Resting membrane potential B. Potential during depolarization

a

Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Resting neuron's permeability to K+ B. Resting neuron's permeability to Na+

a

Indicate whether an excitatory or inhibitory synapse is being described. a. excitatory synapse b. inhibitory synapse Increased PNa+ and increased PK+ of the subsynaptic membrane

a

Indicate whether an excitatory or inhibitory synapse is being described. a. excitatory synapse b. inhibitory synapse Small depolarization of the postsynaptic neuron

a

Indicate whether the membrane is more permeable to K+ or to Na+ or is equally permeable to these ions under the stated conditions: a. more permeable to K+ than to Na+ b. more permeable to Na+ than to K+ c. equally permeable to Na+ and K+ At resting potential

a

Indicate whether the membrane is more permeable to K+ or to Na+ or is equally permeable to these ions under the stated conditions: a. more permeable to K+ than to Na+ b. more permeable to Na+ than to K+ c. equally permeable to Na+ and K+ During an IPSP

a

Indicate whether the membrane is more permeable to K+ or to Na+ or is equally permeable to these ions under the stated conditions: a. more permeable to K+ than to Na+ b. more permeable to Na+ than to K+ c. equally permeable to Na+ and K+ During the falling phase of an action potential

a

Indicate which characteristic applies to classical neurotransmitters and neuropeptides. a. neurotransmitters b. neuropeptides c. both neurotransmitters and neuropeptides d. neither neurotransmitters nor neuropeptides Small: one amino acid or similar chemical

a

Indicate which characteristic applies to classical neurotransmitters and neuropeptides. a. neurotransmitters b. neuropeptides c. both neurotransmitters and neuropeptides d. neither neurotransmitters nor neuropeptides Synthesized in cytosol of synaptic knob

a

Indicate which characteristic applies to classical neurotransmitters and neuropeptides. a. neurotransmitters b. neuropeptides c. both neurotransmitters and neuropeptides d. neither neurotransmitters nor neuropeptides Usually open specific ion channels

a

Match neural disease/influence with correct characteristic. a. multiple sclerosis b. tetanus c. strychnine d. roseola e. Parkinson's disease Destroys myelin

a

Use the answer code below to answer this section. a. increased PNa+ and no change in PK+ b. decreased PNa+ and decreased PK+ c. increased PK+ and no change in PNa+ d. increased PK+ and increased PNa+ e. increased PK+ and decreased PNa+ f. Na influx g. Na+ efflux h. K+ influx i. K+ efflux Permeability changes at threshold voltage

a

Which number identifies the structure that is primarily responsible for the absolute refractory period during an action potential? a. 1 b. 2 c. 3 d. 4 e. None of the above

a

Inulin vs. Creatinine

a carbohydrate that is freely filtered and not absorbed or secreted vs freely filtered at the glomerulus. a small amount is also secreted

Sequence the following events correctly. 1. Neurotransmitter diffuses across cleft. 2. Calcium induces exocytosis of neurotransmitter. 3. Permeability of postsynaptic membrane altered. 4. Ion channels open. 5. Neurotransmitter binds to receptor.

a. 1, 2, 3, 5, 4 b. 1, 4, 3, 2, 5 c. 2, 1, 5, 4, 3 d. 3, 1, 4, 5, 2 e. 5, 4, 3, 1, 2 ANS: C PTS: 1 DIF: Comprehension

The structure labeled "4" is a. part of a channel that allows Na+ ions to diffuse into the ECF b. the activation gate for a gated K+ channel c. the inactivation gate for a gated Na+ channel d. part of a second messenger system e. the activation gate for a gated K+ channel and part of a second messenger system

b

This figure shows a. the mechanism by which some lipid-soluble hormones affect their target cells b. the way insulin affects certain cells c. the method in which IP3 forms d. a common second messenger system for hormone that is derived from cholesterol e. none of these

b

Assume that a hypothetical neuron has three presynaptic inputs: A and B are excitatory, and C is inhibitory. Indicate which of the following changes will take place. a. no change in potential of the postsynaptic cell b. spatial summation c. temporal summation What would occur if both presynaptic neurons A and B were fired simultaneously?

b

Indicate the direction that the force in question tends to move the involved ion under the stated conditions by writing the appropriate letter in the blank, using the following answer code: a. tends to move the involved ion out of the cell b. tends to move the involved ion into the cell Concentration gradient for Na+ at the end of an action potential

b

Indicate the direction that the force in question tends to move the involved ion under the stated conditions by writing the appropriate letter in the blank, using the following answer code: a. tends to move the involved ion out of the cell b. tends to move the involved ion into the cell Concentration gradient for Na+ at threshold potential

b

Indicate the direction that the force in question tends to move the involved ion under the stated conditions by writing the appropriate letter in the blank, using the following answer code: a. tends to move the involved ion out of the cell b. tends to move the involved ion into the cell Electrical gradient for Na+ at threshold potential

b

Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Na+ concentration in the neuron's cytosol immediately before an action potential B. Na+ concentration in the neuron's cytosol immediately following an action potential

b

Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Neuron's permeability to Na+ during the falling phase of an action potential B. Neuron's permeability to K+ during the falling phase of an action potential

b

Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Resting membrane potential B. Potential during hyperpolarization

b

Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Resting neuron's permeability to K+ B. Neuron's permeability to K+ during the falling phase of an action potential

b

Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Resting neuron's permeability to Na+ B. Neuron's permeability to Na+ during the rising phase of an action potential

b

Indicate whether an excitatory or inhibitory synapse is being described. a. excitatory synapse b. inhibitory synapse Increased PCl- of the subsynaptic membrane

b

Indicate whether an excitatory or inhibitory synapse is being described. a. excitatory synapse b. inhibitory synapse Increased PK+ of the subsynaptic membrane (no change in PNa+)

b

Indicate whether an excitatory or inhibitory synapse is being described. a. excitatory synapse b. inhibitory synapse Small hyperpolarization of the postsynaptic neuron

b

Indicate whether the membrane is more permeable to K+ or to Na+ or is equally permeable to these ions under the stated conditions: a. more permeable to K+ than to Na+ b. more permeable to Na+ than to K+ c. equally permeable to Na+ and K+ During an EPSP

b

Indicate whether the membrane is more permeable to K+ or to Na+ or is equally permeable to these ions under the stated conditions: a. more permeable to K+ than to Na+ b. more permeable to Na+ than to K+ c. equally permeable to Na+ and K+ During the rising phase of an action potential

b

Indicate which characteristic applies to classical neurotransmitters and neuropeptides. a. neurotransmitters b. neuropeptides c. both neurotransmitters and neuropeptides d. neither neurotransmitters nor neuropeptides Large: 2 to 40 amino acids in length

b

Indicate which characteristic applies to classical neurotransmitters and neuropeptides. a. neurotransmitters b. neuropeptides c. both neurotransmitters and neuropeptides d. neither neurotransmitters nor neuropeptides Usually function as neuromodulators

b

Match neural disease/influence with correct characteristic. a. multiple sclerosis b. tetanus c. strychnine d. roseola e. Parkinson's disease Prevents release of GABA

b

Resistance to the flow of blood increases when

blood vessel radius decreases

Assume that a hypothetical neuron has three presynaptic inputs: A and B are excitatory, and C is inhibitory. Indicate which of the following changes will take place. a. no change in potential of the postsynaptic cell b. spatial summation c. temporal summation What would occur if presynaptic neuron B were fired rapidly?

c

Choose the match for each substance listed. a. covering on the axon b. second messenger c. branching process from a cell body d. impulse-conducting region e. junction between neurons f. neurotransmitter Dendrite

c

Indicate which characteristic applies to classical neurotransmitters and neuropeptides. a. neurotransmitters b. neuropeptides c. both neurotransmitters and neuropeptides d. neither neurotransmitters nor neuropeptides Released from axon terminal

c

Match neural disease/influence with correct characteristic. a. multiple sclerosis b. tetanus c. strychnine d. roseola e. Parkinson's disease Competes with glycine for receptors

c

Use the answer code below to answer this section. a. increased PNa+ and no change in PK+ b. decreased PNa+ and decreased PK+ c. increased PK+ and no change in PNa+ d. increased PK+ and increased PNa+ e. increased PK+ and decreased PNa+ f. Na influx g. Na+ efflux h. K+ influx i. K+ efflux Permeability changes at the start of an IPSP

c

The second heart sound is produced by the

closing of semilunar valves

A second messenger is labeled a. 1 b. 2 c. 3 d. 4 e. 5

d

Choose the match for each substance listed. a. covering on the axon b. second messenger c. branching process from a cell body d. impulse-conducting region e. junction between neurons f. neurotransmitter Axon

d

Indicate which characteristic applies to classical neurotransmitters and neuropeptides. a. neurotransmitters b. neuropeptides c. both neurotransmitters and neuropeptides d. neither neurotransmitters nor neuropeptides Released into blood for delivery to target

d

Match neural disease/influence with correct characteristic. a. multiple sclerosis b. tetanus c. strychnine d. roseola e. Parkinson's disease May predispose a person to multiple sclerosis

d

A photoreceptor cell exposed to light will undergo graded hyperpolarization that will decrease its release of neurotransmitter.

true

Choose the match for each substance listed. a. covering on the axon b. second messenger c. branching process from a cell body d. impulse-conducting region e. junction between neurons f. neurotransmitter Acetylcholine

f

Use the answer code below to answer this section. a. increased PNa+ and no change in PK+ b. decreased PNa+ and decreased PK+ c. increased PK+ and no change in PNa+ d. increased PK+ and increased PNa+ e. increased PK+ and decreased PNa+ f. Na influx g. Na+ efflux h. K+ influx i. K+ efflux Ion movement responsible for the rising phase of the action potential

f

Use the answer code below to answer this section. a. increased PNa+ and no change in PK+ b. decreased PNa+ and decreased PK+ c. increased PK+ and no change in PNa+ d. increased PK+ and increased PNa+ e. increased PK+ and decreased PNa+ f. Na influx g. Na+ efflux h. K+ influx i. K+ efflux Ion movement that would cause an EPSP

f

Electrical signals move through desmosomes from cell to cell in the cardiac myocardium

false

Mechanical deformation of the hairs on cells in the inner ear always results in depolarization of the hair cell synaptic terminal.

false

The veins have low BP and can serve as a blood reservoir by adjusting their total capacity to accommodate variations in blood volume

false

Unlike skeletal muscles, contractions in cardiac muscle can exhibit summation

false

Loud noises cause action potentials to

fire more frequently

Use the answer code below to answer this section. a. increased PNa+ and no change in PK+ b. decreased PNa+ and decreased PK+ c. increased PK+ and no change in PNa+ d. increased PK+ and increased PNa+ e. increased PK+ and decreased PNa+ f. Na influx g. Na+ efflux h. K+ influx i. K+ efflux Ion movement responsible for the falling phase of the action potential

h

Use the answer code below to answer this section. a. increased PNa+ and no change in PK+ b. decreased PNa+ and decreased PK+ c. increased PK+ and no change in PNa+ d. increased PK+ and increased PNa+ e. increased PK+ and decreased PNa+ f. Na influx g. Na+ efflux h. K+ influx i. K+ efflux Ion movement that would cause an IPSP

i

Alkalosis

pH above 7.45 The blood has too much base (or too little acid), resulting in an increasein blood pH.

Acidosis

pH below 7.35 The blood has too much acid (or too little base), resulting in a decreasein blood pH.

Natural analgesia occurs when

periaquaductal gray matter causes interneurons to release endogenous opiates that bind to receptors on afferent pain fibers

Aldosterone

steroid hormone •Increases blood volume and pressure -acts on the distal tubules and collecting ducts of the nephron, increasing reabsorption and excretion of ions. •conservation of sodium, secretion of potassium, and thereby indirectly influencing water retention or loss, and influencing blood volume and blood pressure

at an excitatory synapse an action potential in the pre-synaptic neuron increases

the permeability of the postsynaptic cell to NA+

Describe. 1. the state of the binding sites for Na AND 2. the state of the binding sites for K when the Na/K ATPase pump is exposed to the extracellular fluid.

1. low affinity 2. high affinity

short term vs long term

(within seconds) adjustments are made by neural control of cardiac output and total peripheral resistance. vs (requiring minutes to days) adjustments are made by controlling total blood volume by adjusting urine output and thirst.

Angiotensin II

-peptide hormone •Raises blood pressure -causes blood vessels to constrict and decreases blood flow to capillaries in the kidney •Stimulates the release of aldosterone

micturition

1) Urine is temporarily stored in the bladder, and emptied 2) The bladder can accommodate up to 250 to 400 ml of urine before stretch receptors initiate micturition

To be reabsorbed, a substance must cross five distinct barriers:

1. The luminal cell membrane 2. the cytosol 3. the basolateral cell membrane 4. the interstital fluid 5. the capillary wall

The diagram below shows the reflex arc for stimulating emptying of the bladder (an example peripheral organ). Also included is the control for relaxing a skeletal muscle sphincter surrounding the urethra (outflow for the urine). When the bladder contracts, the sphincter relaxes.

1. interneurons 2. preganglionic autonomic (parasympathetic) neuron 3. postganglionic autonomic (parasympathetic) neuron 4. somatic motor neuron 5. dorsal root ganglion [+0.5] 6. lateral horn 7. ventral horn 8. terminal ganglion/peripheral organ [+0.25] 9. Ach; nicotinic 10. Ach; muscarinic

On the Wiggers diagram below A. Why does ventricular pressure shoot up suddenly between points A and B? B. What is happening at point A? C. What is happening at point B D. What is point C referring to?

13 a) (1 point) Ventricles are contracting on a fixed volume of blood - IVVC, because both AV and SL/aortic valves are closed b) (1 point) AV valves close due to ventricles starting to contract [producing the first heart sound] c) (1 point) Semilunar/aortic valve opens [pressure in left ventricle exceed aortic pressure] d) (1 point) End diastolic volume - [volume of blood in the ventricle when filling is complete]

Tubuloglomerularfeedback helps GFR autoregulation

80% of the plasma that enters the glomerulus is not filtered and leaves through the efferent arteriole 20% of the plasma that enters the glomerulusis filtered

How does a depolarizing graded potential lead to the propagation of action potentials?

A depolarizing graded potential does not reverse the polarity of the cell membrane, but it moves the potential closer to threshold voltage. If threshold voltage is reached, voltage-gated Na+ channels in that region will open, causing an action potential in which the inside border of the membrane becomes positive. This reversal in polarity causes the membrane potential in the adjacent region to reach threshold, which causes voltage-gated Na+ channels in that region to open. Thus, an action potential in one region will change the voltage in an adjacent region significantly enough to generate an action potential there. This process continues and allows the action potentials to be propagated along the plasma membrane. PTS: 1 DIF: Knowledge

What are four ways in which drugs might influence the nervous system at the neuronal level?

A drug or disease agent might:(1) alter the synthesis, transport, storage, or release of a neurotransmitter; (2) modify the way in which the neurotransmitter interacts with the postsynaptic receptor; (3) influence the neurotransmitters' reuptake or destruction; and (4) replace or substitute for a deficient neurotransmitter. PTS: 1 DIF: Application

Which statement is INCORRECT?

A single hormone can influence only one type of target cell. (Other answers: An endocrine organ may secrete non-endocrine substances in addition to hormones. A single target cell may be influenced by more than one hormone.A single endocrine gland may produce multiple hormones.)

Which glial cells perform the functions in A and B - Astrocytes, microglia, ependymal cells, oligodendrocytes A. (0.5 pt) Contribute to the formation of CSF B. (0.5 pt) Contribute to or induce the formation of BBB

A) Ependymal cells B) Astrocytes

For an experiment, smooth muscle cells and skeletal muscle cells are placed in interstitial fluid.When both cell types are depolarized smooth muscle cells do not contract but skeletal muscles do. A. What would you suggest in absent in the interstitial fluid? B. What conclusion would you draw from this experiment?

A) In this experiment, Calcium (Ca2+) would be absent in the interstitial fluid. B) The conclusion I would draw from this experiment is that, for smooth muscle contraction, Ca from the interstitial or outside of the cell is required (to cause the release of more Ca from the sarcoplasmic reticulum and initiate downstream steps). For skeletal muscle contraction, Ca from the interstitial fluid is not required and all Ca needed for contraction is intracellular (muscle AP causes the release of Ca from the sarcoplasmic reticulum within the cell)

A) Ventricular stretch at the end of diastole B)The amount of resistance the heart must overcome to open the aortic valve

A) Preload B) Afterload

For the following pathologies which would be the associated Group pattern? Explain your reasoning A. (2 points) Primary hyperthyroidism B. (2 points) Secondary hyperthyroidism C. (2 points) Primary hypothyroidism

A. Group B - too much thyroid hormones made by thyroid gland would feedback to inhibit TSH B. Group A - Hyperthyroidism due to increased TSH (not due to thyroid gland dysfunction) C. Group A - too little thyroid hormones made by thyroid gland would stimulate TSH (increase TSH levels)

A new cardiac drug called Ivabradine selectively blocks If (funny channels) in the heart A. Where are the funny channels located? B. What effect would this drug have on the heart rate? and Why? C. What medical condition might it be useful for?

A. In pacemaker cells B. Blocking If channels would slow heart rate. Drug would block Na induced depolarization of pacemaker potential C. Therefore it could be useful for lowering abnormally high heart rates (tachycardia). [Also useful in ischemic heart disease (heart failure) as lowering heart rate reduces myocardial oxygen demand, mitigating ischemia] (stable angina okay)

The transduction of stimuli by sensory receptors can be subject to two modifications- adaptation and amplification, A. (1 point) Immediately after putting on a shirt, your skin might feel itchy. However, this perception soon fades. Briefly explain the type of sensory receptor that adapts to this stimulus and how it may modify sensory transduction. B. (1 point) You accidentally burn your left finger on the stove and sense the pain for several hours. Briefly explain the type of sensory receptor that adapts to this stimulus and how it may modify sensory transduction. C. (1 point) The pain sensation from your burnt left finger is carried via the spinothalamic tract. Which brain hemisphere will perceive the sensation and why? D. (1 point) Briefly explain how sensory transduction is amplified when light hits the eye.

A. Phasic receptor - rapidly adapts to stimulus and does not transduce stimulus even in its presence B. Tonic receptor)- slowly adapts or does not adapt to stimulus and continues to transduce stimulus C. Right hemisphere because the spinothalamic tract ascends contralateral - opposite side as the sensory receptor. Refer to slide 8 of sensory systems. D. one photon triggers a cascade of events to close many CNG channels, signal is amplified

A. (0.5 pt) What branch of the autonomic division would these drugs be inhibiting? B. (1.5 pts) If a patient is prescribed a non-selective b-blocker (that acts on other tissues besides heart due to blocking b1 and b2 receptor subtypes), why should you caution its use if the patient has asthma (difficulty breathing)?

A. Sympathetic B. Sympathetic system causes bronchodilation (dilates airways). The non-selective b-blocker would block the receptors in the lung preventing bronchodilation thus exacerbating asthma. The non selective blocker will block b2 receptor on the bronchial SM cells therefore the bronchodilation mediated by the sympathetic system via b2 receptor will be prevented (that is needed during asthma attack). The non selective blocker will not cause bronchoconstriction as constriction is mediated by the parasympathetic division via M3 receptor.

T/F Cocaine blocks the binding of dopamine at postsynaptic membranes.

ANS: F PTS: 1 DIF: Knowledge

A) Basal nuclei (or basal ganglia) are several masses of gray matter. Where are they specifically located? What problem or disease is associated with the destruction of neurons in the basal nuclei? For each activity listed, name the region of the brain responsible, and state specifically where that region is located within the brain: B. your ability to raise your hand C. your ability to sense someone's fingers on your back

A. located deep within white matter in the cerebrum (0.5pt); Parkinson's disease (PD) or involuntary muscle tremors (0.5pt) B. primary motor cortex (0.5pt), Frontal lobe (just anterior to central sulcus) (0.5pt) C. somatosensory cortex (0.5pt), Parietal lobe (just posterior to the central sulcus) (0.5pt)

A (1 pt) Which region of the brain helped you learn something new, remember what you have learnt and which cerebral lobe is it located in. B. (1 pt) At the synapses in that brain region, glutamate plays a role in the molecular mechanism of memory formation. What is the short term effect of glutamate after it acts on the post-synaptic neuron? C. (1 pt) At the synapses in that brain region, glutamate plays a role in the molecular mechanism of memory formation. What is the long term effect of glutamate after it acts on the post-synaptic neuron?

A: hippocampus; temporal lobe B: paracrine release of more glutamate from the presynaptic neuron C: Second msg pathways/increased receptor expression on post synaptic neuron/cell become more sensitive to glutamate.

The resting membrane potential of a typical nerve cell is about ____________________ millivolts.

ANS: -70 PTS: 1 DIF: Knowledge

Myelinated fibers conduct impulses about ____________________ times faster than unmyelinated fibers of the same diameter.

ANS: 50 PTS: 1 DIF: Knowledge

A change in a membrane potential from -70 mV to -60mV is an example of a. depolarization b. hyperpolarization c. polarization d. repolarization e. zero potential

ANS: A PTS: 1 DIF: Comprehension

If neuron Y's neurotransmitter is causing neuron X's membrane potential to decrease, then we would logically conclude that this neurotransmitter causes a. increased PNa+ and PK+ b. increased PK+ or PCl- c. increased permeability to protein anions d. increased permeability to calcium ions e. None of the above

ANS: A PTS: 1 DIF: Comprehension

If neurotransmitter from Y causes the membrane potential of the postsynaptic cell to decrease slightly, then a. the synapse is excitatory b. the postsynaptic membrane's potential will be farther away from threshold c. the postsynaptic membrane causes an EPSP on the presynaptic membrane d. neurotransmitter from Y causes an IPSP on the presynaptic membrane e. both a and c are correct

ANS: A PTS: 1 DIF: Comprehension

Which of the following is least related to a description of contiguous conduction on a neuron? a. dendrite b. action potential c. refractory period d. unmyelinated axon e. nondecremental propagation

ANS: A PTS: 1 DIF: Comprehension

Which statement is correct? a. In presynaptic inhibition, another neuron inhibits an excitatory presynaptic input. b. An IPSP depresses information fed into the cell from an inhibitory presynaptic input. c. Not all axon terminals of an inhibitory neuron release inhibitory neurotransmitter. d. During presynaptic inhibition, there is no change in presynaptic membrane potential. e. An IPSP decreases the potential of the postsynaptic neuron.

ANS: A PTS: 1 DIF: Comprehension

Graded potentials a. are local changes in membrane potential that occur in varying degrees of magnitude b. are weak action potentials c. serve as long-distance signals d. are only depolarizations e. always lead to action potentials

ANS: A PTS: 1 DIF: Knowledge

In convergence, a. many presynaptic cells synapse with a single postsynaptic cell b. one axon directly influences the activity of many other cells c. many dendrites converge on one cell body d. all of the above are true e. none of the above are true

ANS: A PTS: 1 DIF: Knowledge

Which statement is true about the absolute refractory period? a. It ensures that action potentials move in only one direction along a nerve fiber. b. It is the period when the membrane can undergo another action potential, but only if the stimulus is strong enough. c. It is the time during an action potential when voltage-gated Na+ channels are in their "closed but capable of opening" conformation. d. places a lower limit on the frequency with which a neuron can conduct action potentials. e. All of the above statements are true.

ANS: A PTS: 1 DIF: Knowledge

Which term best describes an excitable cell when a resting membrane potential is present? a. polarized b. depolarized c. hyperpolarized d. repolarized e. nonpolarized

ANS: A PTS: 1 DIF: Knowledge

At an excitatory synapse, an action potential in the presynaptic neuron increases a. the membrane potential of the postsynaptic cell membrane b. the permeability of the postsynaptic cell to Na+ c. the permeability of the postsynaptic cell to Cl- d. the presynaptic neuron's membrane potential e. all of the above

ANS: B PTS: 1 DIF: Comprehension

At an inhibitory synapse, the postsynaptic membrane experiences a. an increase in permeability to both Na+ and K+ b. an increase in membrane potential c. hyperpolarization d. an influx of cations e. all of the above

ANS: B PTS: 1 DIF: Comprehension

If neuron X causes hyperpolarization, then what does it cause in a postsynaptic neuron? a. Increased PNa+ and PK+ b. Increased PK+ or PCl- c. Increased influx of protein anions d. Increased permeability to calcium ions e. Either b or c

ANS: B PTS: 1 DIF: Comprehension

If neurotransmitter from X causes a slight hyperpolarization of a postsynaptic cell, then a. the synapse is excitatory b. the synapse is inhibitory c. the postsynaptic cell's membrane potential is becoming less negative d. the postsynaptic cell's membrane potential is becoming more positive e. b, c, and d are occurring

ANS: B PTS: 1 DIF: Comprehension

Opening either a chemically-gated Na+ channel or a chemically-gated K+ channel during the resting potential would cause a. an impulse to be propagated b. a graded potential c. an action potential d. the membrane's potential to becomes more negative e. threshold voltage will be reached

ANS: B PTS: 1 DIF: Comprehension

When the membrane potential is +15 mV, that portion of the membrane a. is at the normal resting potential b. has a positively-charged inside border c. is more permeable to Ca2+ than normal d. is in the after hyperpolarization phase of an action potential e. is in a hyperpolarized state

ANS: B PTS: 1 DIF: Comprehension

Which statement is incorrect? a. Inhibitory synapses cause postsynaptic hyperpolarization. b. An inhibitory synapse may result in postsynaptic sodium channel opening. c. An inhibitory synapse may result in increased postsynaptic potassium efflux. d. An excitatory synapse causes depolarization of postsynaptic membranes. e. An excitatory synapse increases sodium permeability.

ANS: B PTS: 1 DIF: Comprehension

An IPSP is a. produced by increased permeability to Na+ and K+ b. produced by increased permeability to K+ or Cl- c. a hyperpolarization of the presynaptic cell d. a decrease in the postsynaptic membrane potential e. an decrease in the presynaptic membrane potential

ANS: B PTS: 1 DIF: Knowledge

During the peak of the action potential, the membrane becomes most permeable to a. sodium b. potassium c. calcium d. chloride e. protein

ANS: B PTS: 1 DIF: Knowledge

During the rising phase of the action potential, a. PK+ is much greater than PNa+ b. PNa+ is much greater than PK+ c. PK+ is the same as P Na+ d. Na+ efflux occurs e. b and d are true

ANS: B PTS: 1 DIF: Knowledge

Spatial summation occurs on a postsynaptic neuron would occur when a. several EPSPs from a single presynaptic input sum to reach threshold b. EPSPs from several presynaptic inputs sum to reach threshold c. there is simultaneous interaction of an EPSP and an IPSP d. several IPSPs from a single presynaptic input sum to hyperpolarize the membrane e. none of the above take place

ANS: B PTS: 1 DIF: Knowledge

The falling phase of the action potential is due to a. calcium influx b. potassium efflux c. chloride influx d. sodium efflux e. the action of Na+-K+ pumps

ANS: B PTS: 1 DIF: Knowledge

The nodes of Ranvier are a. action potential recordings b. breaks in the myelin covering c. spaces between neurons d. specialized cells around axons e. structures on axon terminals that release neurotransmitter

ANS: B PTS: 1 DIF: Knowledge

Which channel type is sensitive to serotonin? a. voltage-gated b. chemically-gated c. mechanically-gated d. acoustically-gated e. none of these

ANS: B PTS: 1 DIF: Knowledge

Which of the following is not a graded potential? a. end-plate potential b. action potential c. slow-wave potential d. receptor potential e. postsynaptic potential

ANS: B PTS: 1 DIF: Knowledge

Which of the following is not true for lipophilic hormones? a. Cells do not store them. b. They are all derived from cholesterol. c. They are bound to protein in the blood. d. They typically activate genes. e. Only a small portion of the hormone is biologically active.

ANS: B PTS: 1 DIF: Knowledge

A hypothetical postsynaptic neuron has three presynaptic inputsX, Y, and Z. When X and Y are stimulated simultaneously, the postsynaptic neuron undergoes an action potential, yet when X and Z are stimulated simultaneously, there is no change in the postsynaptic neuron's potential. What can you logically conclude? a. Y and Z are both excitatory. b. Y and Z are both inhibitory. c. Y is excitatory and Z is inhibitory. d. Y is inhibitory and Z is excitatory. e. Not enough information to answer.

ANS: C PTS: 1 DIF: Application

If a neuron were experimentally stimulated at both ends simultaneously, then a. the action potentials would pass in the middle and travel to the opposite ends b. the action potentials would meet in the middle and then be propagated back to their starting positions c. the action potentials would stop as they met in the middle d. the strongest action potential would override the weaker action potential e. summation would occur when the action potentials met in the middle, resulting in a two larger action potentials traveling in opposite directions

ANS: C PTS: 1 DIF: Application

T/F Common second messengers include cAMP, acetylcholine, and calcium ions.

ANS: F PTS: 1 DIF: Knowledge

The period following an action potential during which a membrane cannot experience another action potential a. is the absolute refractory period b. occurs during the time after the Na+ gates have opened until they are restored to their "closed but capable of opening" state c. prevents the action potential from spreading back over the part of the membrane where the impulse has just passed d. includes the time when Na+ gates are in a "closed and not capable of opening" state e. includes all of the above

ANS: E PTS: 1 DIF: Comprehension

Which of the following characteristics is least related to steroid hormones? a. Binds to intracellular receptor b. Transported bound in the blood c. May bind to hormone response element d. Stimulate protein synthesis e. Utilize a G protein

ANS: E PTS: 1 DIF: Comprehension

Which of the following is responsible for the falling phase of an action potential? a. opening of Na+ gates b. Na+-K+ pump restoring the ions to their original locations c. greatly increased permeability to Na+ d. Na+ efflux e. none of these

ANS: E PTS: 1 DIF: Comprehension

An action potential on a neuron develops when a. threshold voltage is reached on an axon b. voltage-gated Na+ channels open c. spatial or temporal summation of graded potentials occurs to a great enough degree d. the axon hillock reaches threshold voltage e. any of the above events occur

ANS: E PTS: 1 DIF: Knowledge

Drugs may influence synaptic transmission by a. altering the formation of neurotransmitters b. blocking neurotransmitter reuptake c. blocking receptors d. blocking channels e. all of the above

ANS: E PTS: 1 DIF: Knowledge

Identify a second-messenger. a. Insulin b. G protein c. G protein coupled receptor d. Adenylyl cyclase e. None of the above

ANS: E PTS: 1 DIF: Knowledge

In most excitable cells, the rising phase of the action potential is due to a. calcium efflux b. potassium efflux c. chloride influx d. potassium influx e. sodium influx

ANS: E PTS: 1 DIF: Knowledge

Myelinated axons conduct impulses much faster because a. the myelin insulates the axon b. ion channels only have to open at the nodes c. voltage is not lost along myelinated areas d. saltatory conduction occurs e. all of the above are true

ANS: E PTS: 1 DIF: Knowledge

Select the incorrect statement about the action potential. a. It has an all-or-none characteristic b. It has a refractory period c. It is triggered by depolarization to threshold d. It occurs along a plasma membrane e. It speeds up transmission by summation

ANS: E PTS: 1 DIF: Knowledge

The normal direction for the movement of an action potential along part of a neuron is from a. axon hillock to cell body b. axon terminal to collateral axon c. axon to dendrite d. cell body to receptor e. dendrite to cell body

ANS: E PTS: 1 DIF: Knowledge

What is responsible for development of the resting membrane potential? a. Leak channels b. Gated channels c. Ion pumps d. both a and b e. both a and c

ANS: E PTS: 1 DIF: Knowledge

T/F The time following an action potential during which a membrane cannot respond to another stimulus, regardless of its strength, is called the relative refractory period.

ANS: F Absolute refractory period PTS: 1 DIF: Knowledge

T/F Along a neuron, an action potential normally travels from the dendrites to the cell body to the axon.

ANS: F Dendrites and cell bodies do not conduct action potentials. PTS: 1 DIF: Knowledge

T/F A lipophilic chemical messenger uses a second messenger system to alter the activity of a target cell.