Deck 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals

Question 1

Which statement regarding ions is true?

A) Positively charged cations are attracted to the intracellular fluid.
B) Positively charged anions are attracted to the intracellular fluid.
C) Negatively charged anions are drawn to the intracellular fluid.
D) Negatively charged anions are balanced across the cell membrane.

Answer 1

A

Question 2

Electrostatic pressure derives from

A) the force that causes molecules to diffuse from high concentration to low concentration.
B) the distribution of electrical charges.
C) the distribution of molecules.
D) selective permeability.

Answer 2

B

Question 3

Inside the neuron there is a high concentration of _______ ions, while outside the cell there is a high concentration of _______ ions.

A) potassium; sodium
B) sodium; potassium
C) calcium; sodium
D) calcium; chloride

Answer 3

A

Question 4

The sodium-potassium pump is responsible for

A) exchanging three sodium ions for every two potassium ions from the intracellular environment.
B) initiating the action potential.
C) maintaining the equilibrium potential.
D) exchanging three potassium ions for every two sodium ions from the intracellular environment.

Question 5

The resting membrane potential is maintained by electrostatic pressure and _______ acting on the cation _______.

A) permeability; sodium
B) local potential; calcium
C) afterpotential; chloride
D) diffusion; potassium

Question 6

The equilibrium potential corresponds to

A) the rising phase of the action potential.
B) the afterpotential.
C) the membrane potential at which the movement of ions across the membrane is balanced.
D) temporally summated graded potentials.

Question 7

An action potential can be likened to the action of what common household fixture?

A) Microwave
B) Water heater
C) Dishwasher
D) Toilet

Question 8

Hyperpolarizing stimuli

A) decrease the likelihood the neuron will fire an action potential.
B) increase the likelihood the neuron will fire an action potential.
C) increase movement of sodium ions into the neuron.
D) decrease the membrane potential.

Question 9

Action potentials are all-or-none phenomena. This means that

A) they must fire a certain number of times a second to communicate information accurately.
B) they require a certain amount of stimulus to fire.
C) the amplitude of the action potential is independent of the size of the stimulus.
D) the amplitude of the action potential changes based on the intensity of the stimulus.

Question 10

The size of the action potential is independent of stimulus magnitude. This is referred to as the _______ property of action potentials.

A) ionic
B) resting
C) all-or-none
D) threshold

Question 11

After the spike of an action potential, axons may exhibit small potential changes, called

A) the threshold.
B) afterpotentials.
C) micropotentials.
D) the refractory phase.

Question 12

The peak of the action potential is caused by the _______ of _______ channels.

A) opening; potassium
B) closing; potassium
C) opening; sodium
D) closing; sodium

Question 13

During the relative refractory phase,

A) voltage-gated sodium channels are open.
B) all gated channels are closed.
C) no amount of stimulation can induce another action potential.
D) the neuron is briefly hyperpolarized.

Question 14

The generation of the action potential depends on _______ channels, which are opened through a process of regenerative _______.

A) potassium; hyperpolarization
B) potassium; depolarization
C) sodium; hyperpolarization
D) sodium; depolarization

Question 15

The _______ are regularly spaced along the length of myelinated axons.

A) nodes of Ranvier
B) dendrites
C) ion channels
D) sodium-potassium pumps

Question 16

The conduction velocity of an action potential

A) is always the same, no matter how large the axon is.
B) varies, depending on where it is taking place in the brain.
C) varies, depending on the diameter of the axon.
D) is dependent upon the water content in the myelin of each specific neuron.

Question 17

Action potentials generally are not propagated along dendrites because dendrites usually have few

A) voltage-gated ion channels.
B) sodium channels.
C) myelin.
D) cell membranes.

Question 18

Myelin increases the speed of conduction because it

A) offers little resistance to the flow of ionic current.
B) releases special chemicals that aid conduction.
C) increases ionic transfer across the membrane.
D) offers considerable resistance to the flow of ionic current.

Question 19

The form of conduction that is characteristic of myelinated axons is called

A) Ranvier diffusion.
B) saltatory conduction.
C) progressive conduction.
D) insulated diffusion.

Question 20

Which statement about multiple sclerosis is false?

A) It damages myelin.
B) It interferes with saltatory conduction.
C) It causes complex partial seizures.
D) Currently there is no cure.

Question 21

A neuron can be pushed to threshold if many EPSPs arrive at the axon hillock in quick succession. This process is referred to as

A) active propagation.
B) spatial summation.
C) temporal summation.
D) threshold afterpotential.

Question 22

A neuron can be pushed to threshold if many EPSPs arrive at the axon hillock at the same time, but from different locations across the cell body. This process is referred to as

A) active propagation.
B) spatial summation.
C) temporal summation.
D) threshold afterpotential.

Question 23

Inhibitory postsynaptic potentials are characterized by _______ the postsynaptic membrane.

A) depolarization of
B) hyperpolarization of
C) decreased threshold of
D) no change in

Question 24

Neurophysiology is the study of

A) the electrical activity of neurons.
B) neurons and neurotransmitters.
C) the life processes of neurons.
D) the nervous system.

Question 25

Ions are molecules that carry an electric charge due to the gain or loss of

A) protons.
B) electrons.
C) neutrons.
D) positrons.

Question 26

A key causal event in the release of neurotransmitter molecules from vesicles into the synaptic cleft is the

A) influx of sodium ions in response to the arrival of an action potential at the terminal.
B) influx of calcium ions in response to the arrival of an action potential at the terminal.
C) efflux of sodium ions in response to the arrival of an action potential at the terminal.
D) efflux of calcium ions at the axon hillock.

Question 27

A ligand is a

A) type of drug.
B) type of electrical stimulus.
C) cholinergic synapse.
D) substance that binds to receptor molecules.

Question 28

Any substance that binds to a receptor is known as a(n)

A) agonist.
B) antagonist.
C) ligand.
D) ion.

Question 29

The toxins bungarotoxin and curare both block _______ receptors, preventing _______.

A) GABA; postsynaptic IPSPs
B) ACh; muscle contractions
C) glycine; event-related potentials
D) glutamate; postsynaptic EPSPs

Question 30

The enzyme _______ breaks down molecules of the neurotransmitter acetylcholine, stopping its action at synapses.

A) curare
B) bungarotoxin
C) monoamine oxidase
D) acetylcholinesterase

Question 31

Transporter molecules are involved in the _______ of neurotransmitter at the synapse.

A) reuptake
B) degradation
C) activation
D) diffusion

Question 32

After release, neurotransmitters are deactivated in the synapse by

A) afterpotentials.
B) the process of enzymatic degradation.
C) postsynaptic receptors.
D) reverse transmitters.

Question 33

Which molecule is a cholinergic antagonist?

A) Bungarotoxin
B) Nicotine
C) Dopamine
D) Acetylcholine

Question 34

The nicotinic ACh receptor has _______ ligand-binding site(s).

A) 1
B) 2
C) 3
D) 4

Question 35

The active ingredient in tobacco products _______ the action of _______.

A) inhibits; acetylcholine
B) inhibits; GABA
C) mimics; acetylcholine
D) mimics; GABA

Question 36

The substance curare, which is used by native South Americans for poisoning the tip of arrowheads,

A) selectively blocks sodium channels.
B) selectively blocks potassium channels.
C) increases levels of acetylcholinesterase.
D) blocks acetylcholine receptors.

Question 37

Cholinergic receptors use _______ as their synaptic transmitter.

A) ACh
B) dopamine
C) AChE
D) nicotine

Question 38

Axo-axonic synapses

A) do not exist in mammalian species.
B) often terminate near the axon terminal.
C) often terminate on the dendritic spine.
D) are always inhibitory.

Question 39

Which type of synaptic connection allows the presynaptic neuron to strongly facilitate or inhibit the activity of the postsynaptic neuron?

A) Axo-axonic
B) Axo-dendritic
C) Axo-somatic
D) Dendro-dendritic

Question 40

Which characteristic is not a factor in the speed of the knee-jerk reflex?

A) Myelination
B) Fast synapses
C) IPSPs
D) Axon diameter

Question 41

A tap on the patellar tendon activates

A) the knee jerk reflex.
B) an oscillator circuit.
C) the flexion reflex.
D) the yawning reflex.

Question 42

To determine if someone is legally dead many countries employ the use of an

A) ERP.
B) EKG.
C) MRI.
D) EEG.

Question 43

One of the benefits of ERPs is they

A) can reliably detect seizure activity.
B) average out background cortical noise.
C) have an unpredictable wave shape.
D) can isolate damage in deep brain structures.

Question 44

The early components of event-related potentials are associated primarily with

A) cognitive processing.
B) endogenous factors.
C) cortical responses.
D) brainstem activity.

Question 45

Event-related potentials are particularly useful for diagnosing problems with _______ at birth.

A) breathing
B) muscle contraction
C) hearing
D) vision

Question 46

Complex partial seizures are often preceded by an unusual sensation referred to as

A) psychomotor retardation.
B) a predrome.
C) an aura.
D) proxy.

Question 47

Spike-and-wave EEG activity is evident for _______ seconds during a simple partial seizure.

A) 1‒5
B) 5‒15
C) 15‒30
D) 30‒45

Question 48

Desynchronized electrical activity is seen

A) during a seizure.
B) only in brainstem structures.
C) in a normal active brain.
D) only in children.

Question 49

_______ seizures are most often accompanied by an unusual sensation called an aura and may not necessarily involve the entire brain.

A) Tonic-clonic
B) Complex partial
C) Simple partial
D) Clonic

Question 50

Loss of consciousness and intense bursts of synchronized EEG are characteristic of _______ seizures.

A) tonic-clonic
B) complex partial
C) simple partial
D) focal

Question 51

Which statement about complex partial seizures is true?

A) They do not involve the entire brain.
B) They produce a set of characteristic behaviors.
C) They are more common in the elderly.
D) During an episode, a person will stop moving and stare into space.

Question 52

If you were to record EEG from six parts of the brain during a tonic-clonic seizure, you would see

A) different gradations of spiking activity.
B) the same relative intensity of spiking from each part of the brain.
C) variable intensity of spiking depending on the locus of seizure onset.
D) no activity in brainstem structures during the seizure.

Question 53

Research is currently underway into _______ as a potential treatment for seizures.

A) curare
B) glutamate
C) caffeine
D) cannabidiol

Question 54

_______ was a pioneer in mapping the brain through electric stimulation.

A) John Hughlings Jackson
B) Marco Delgado
C) Wilder Penfield
D) Eric Kandel

Question 55

Stimulation of the precentral and postcentral gyrus helped determine the location of _______ and _______ cortex, respectively.

A) sensory; motor
B) motor; sensory
C) language; emotion
D) emotion; language

Question 56

Stimulation studies were able to create "maps" of how the various parts of the body are laid out on the cortex. These maps provided the basis for the cartoon depiction of areas of greatest representation in the brain. This cartoon depiction is referred to as the

A) homunculus.
B) petite fille.
C) grand homme.
D) mini-self.

Question 57

The term still used to depict Penfield's maps of the brain is the

A) sulcus.
B) electric mind maps.
C) aura.
D) homunculus.

Question 58

During the _______ phase, an action potential cannot be initiated because Na⁺ channels are unresponsive.

Question 59

During an action potential, the small potential change after a spike is called the _______.

Question 60

Application of a _______ stimulus to a neuron makes it less likely to fire.

Question 61

_______velocity refers to the speed at which an action potential travels down the axon.

Question 62

In saltatory conduction, the action potential jumps from one _______ to the next.

Question 63

During the process of _______, transmitter molecules are reabsorbed by the same axon terminal that originally released them.

Question 64

The enzyme acetylcholinesterase terminates the activity of the transmitter acetylcholine through the process of_______.

Question 65

Following an action potential at the presynaptic membrane, the presynaptic terminal is depolarized, and there is an influx of _______ ions.

Question 66

The plant poison, _______ is an antagonist that blocks ACh receptors.

Question 67

Nicotine, which acts like a transmitter at a receptor, is referred to as an _______ of that receptor.

Question 68

What accounts for and maintains the resting potential?

Question 69

What are sodium-potassium pumps and what is their function?

Question 70

Explain the events that occur at the axon hillock to trigger an action potential.

Question 71

How is the absolute refractory period different from the relative refractory period?

Question 72

How do excitatory postsynaptic potentials (EPSPs) differ from inhibitory postsynaptic potentials (IPSPs)?

Question 73

Outline the sequence of synaptic events that take place during chemical synaptic transmission.

Question 74

Create a short paragraph using the following terms: Transporters, reuptake, degradation, acetylcholinesterase, acetylcholine, dopamine

Question 75

Explain the difference between agonists and antagonists, and provide an example of each.

Question 76

What is the electroencephalogram (EEG) and what does it detect?

Question 77

What are complex partial seizures?

Question 78

Give a detailed explanation of how the resting membrane potential is established and how it is maintained.

Question 79

Discuss how an action potential can be likened to a toilet. Highlight each component of the action potential and the aspects of flushing to which each corresponds.

Question 80

Summarize the various mechanisms by which ion channels may change their shape, thereby altering ion flow through the cell membrane.