Questions

Question 1

Afferent and efferent are terms:

a. For neurons always found only in the Central Nervous System.
b. For neurons that carry information between each other.
c. For the parts of neurons where most inputs occur.
d. To describe whether a neuron is conducting information to or from the CNS.
e. To describe the integrative and conducting parts of a neuron.

Answer 1

Afferent and efferent are terms:

d. To describe whether a neuron is conducting information to or from the CNS.

Afferent = sensory nerves that carry nerve impulses from sensory stimuli to the CNS. Efferent carries nerve impulses from CNS to muscle to stimulate movement

Question 2

Gating of an ion channel

a. Depends on the type of ion that moves through the channel.
b. Is controlled by chemicals, voltage or membrane stress.
c. Will determine whether there is a concentration gradient for the ion that moves through the channel.
d. Will determine whether there is an electrical gradient for the ion that moves through the channel.
e. Will be determined by where the ion channel is located on the dendrites.

Answer 2

Gating of an ion channel

b. Is controlled by chemicals, voltage or membrane stress.

Gating is the closing or activation of ion channels

Question 3

Gating of an ion channel means that:

a. movement of ions through the channel is always passive.
b. the channel is selective as to which ions move through.
c. the opening or closing of the channel is controlled.
d. the channel is always responsible for producing Action Potentials.
e. the opening or closing of the channel depends on the electro-chemical gradients for that ion.

Answer 3

Gating of an ion channel means that:

c. the opening or closing of the channel is controlled.

Question 4

Integration of the different inputs that a neuron receives:

a. Always occurs at the dendrites of a neuron.
b. Depends on whether the neuron is myelinated or unmyelinated.
c. Generally occurs along the axon of a neuron.
d. Generally occurs at the axon hillock of a neuron.
e. Depends on whether the neuron has microtubules or dendrites.

Answer 4

Integration of the different inputs that a neuron receives:

d. Generally occurs at the axon hillock of a neuron.

Dendrites collect info
Axon hillock integrates inco
Axon carries info
Synapse transmits info

Question 5

Interneurons:

a. transmit information to directly control skeletal muscle.
b. are the regions of a neuron where other neurons make contact (synapse).
c. are the regions of a neuron through which ions can cross the membrane.
d. transmit information from one neuron to another.
e. transmit information between neurons only over short distances.

Answer 5

Interneurons

d. transmit information from one neuron to another.

Interneurons are found in the CNS only, not the peripheral nervous system.

Question 6

In the CNS, a nucleus is:

a. a collection of nerve axons carrying information from the peripheral nervous system to the CNS.
b. a collection of nerve cell bodies.
c. a collection of ganglia.
d. the structure that provides support to neurons.
e. responsible for providing the myelin sheath around the axon of neurons.

Answer 6

In the CNS, a nucleus is:

b. a collection of nerve cell bodies.

Ganglia contain nerve cell bodies and glial cells

Question 7

The dendrites of a neuron are:

a. the cytoplasmic extensions of the cell body at which neurons receive most of their inputs.
b. the output functional component of a neuron and the sites where chemicals are released.
c. the regions of a myelinated neuron which are sheathed by Schwann cells.
d. the sites at which a neuron integrates inputs.
e. the structures that give rigidity to the cell body.

Answer 7

The dendrites of a neuron are:

a. the cytoplasmic extensions of the cell body at which neurons receive most of their inputs.

Dendrites can be used to categorise neurons
Usually, dendrites that branch out more tell us that it is located in an area where there is a lot of information input, such as the eye.

Question 8

The two types of cells of the nervous system are called:

a. neurons and ganglia cells.
b. nuclei and ganglia cells.
c. neurons and glial cells.
d. afferent and efferent cells.
e. somatic and autonomic cells.

Answer 8

The two types of cells of the nervous system are called:

c. neurons and glial cells.

ganglia = plural of ganglion
= nerve cluster of glia + neurons

glia = oligdendria, schwann, microglia, astrocytes, epidural (for CSF)

Question 9

Unmyelinated axons differ from myelinated axons in that unmyelinated axons:

a. are not associated with Schwann cells.
b. are always larger so that they can transmit action potentials more quickly.
c. transmit action potentials by saltatory conduction.
d. do not have dendrites or axon hillocks.
e. do not have nodes of Ranvier.

Answer 9

Unmyelinated axons differ from myelinated axons in that unmyelinated axons:

e. do not have nodes of Ranvier

Nodes of Ranvier are found between sections of myelin sheath

Question 10

Which one of the following statements is CORRECT?

a. Movement of ions through gated ion channels always is a passive process that does not require energy expenditure.
b. Gated ion channels are only those channels associated with the active pump.
c. Gated ion channels are integral membrane carbohydrates.
d. Gated ion channels are only those ion channels that can be made refractory.
e. Gated ion channels are always so selective that they allow only one type of ion to pass through.

Answer 10

Which one of the following statements is CORRECT?

a. Movement of ions through gated ion channels always is a passive process that does not require energy expenditure.

Question 11

At a chemical synapse:

a. action potentials are produced by chemical vesicles.
b. binding of chemicals to receptors causes the opening of voltage-gated vesicles in the post-synaptic cell.
c. pre-synaptic terminal depolarisation ultimately causes release of chemicals from vesicles.
d. transmission of activity from pre-synaptic to post-synaptic cells occurs through second messengers.
e. second messengers allow the binding of vesicles to the pre-synaptic membrane.

Answer 11

At a chemical synapse:

c. pre-synaptic terminal depolarisation ultimately causes release of chemicals from vesicles.

Vesicles release info containing AP, but do not produce it. APs are produced by different ions across neuronal membrane.

Second messengers are molecules that relay signals received at the post synaptic terminal. They are extracellular factors, and are often hormones or neurotransmitters.

Question 12

At the post-synaptic cell, neurotransmitters produce voltage changes:

a. only by binding to membrane-bound receptors that form ion channels.
b. only by binding to receptors that are protein complexes made up of five sub-units.
c. that are always a depolarization of the post-synaptic resting membrane potential.
d. that may be a depolarization or a hyper-polarization of the post-synaptic resting membrane potential.
e. through receptors that selectively allow the movement of only one ion.

Answer 12

At the post-synaptic cell, neurotransmitters produce voltage changes:

d. that may be a depolarization or a hyper-polarization of the post-synaptic resting membrane potential.

Question 13

Peptidergic synapses differ from non-petidergic synapses in that:

a. Peptidergic synapses do not store transmitter in vesicles.
b. Peptidergic synapses have few vesicles of transmitter docked at the docking proteins at the active zone.
c. Peptidergic synapses transmit information more efficiently.
d. Peptidergic synapses synthesize transmitter in the terminal and vesicles in the cell body.
e. Peptidergic synapses do not require terminal depolarization for synaptic transmission.

Answer 13

Peptidergic synapses differ from non-petidergic synapses in that:

b. Peptidergic synapses have few vesicles of transmitter docked at the docking proteins at the active zone.

Peptidergic = neurons that secrete peptides

Question 14

Which of the following statements about terminating neurotransmitter action is CORRECT?

a. The actions of some neurotransmitters are terminated by re-uptake of the chemical into the terminal.
b. The actions of all neurotransmitters are terminated by degradation by enzymes within the synaptic cleft.
c. The actions of some neurotransmitters are terminated by simple diffusion of the chemical back into the pre-synaptic terminal.
d. The actions of some neurotransmitters are terminated by binding of the chemical to G proteins in the pre-synaptic terminal.
e. The actions of all neurotransmitters are terminated by re-uptake of the chemical into glial cells.

Answer 14

Which of the following statements about terminating neurotransmitter action is CORRECT?

a. The actions of some neurotransmitters are terminated by re-uptake of the chemical into the terminal.

Question 15

Which of the following statements about vesicle fusion and transmitter release is INCORRECT?

a. Only vesicles bound to docking proteins can fuse with the pre-synaptic membrane.
b. Vesicle fusion with the terminal membrane can occur only in the region of the active zones.
c. Calcium entry into the terminal occurs only through voltage-gated channels.
d. Voltage-gated calcium channels are found across the entire surface of the terminal.
e. After fusion with the terminal membrane and release of neurotransmitter, the vesicle membrane is recycled within the terminal.

Answer 15

Which of the following statements about vesicle fusion and transmitter release is INCORRECT?

d. Voltage-gated calcium channels are found across the entire surface of the terminal.

Question 16

Which of the following statements comparing transmitter-gated channels and voltage-gated channels is CORRECT?

a. Transmitter-gated channels are as selective for ions as are voltage-gated channels.
b. Transmitter-gated channels and voltage-gated channels always produce a depolarisation.
c. Transmitter-gated channels and voltage-gated channels always have a central water-filled pore allowing ionic movement.
d. Transmitter-gated channels and voltage-gated channels can produce fast voltage changes or slow effects through G proteins.
e. Transmitter-gated channels and voltage-gated channels are both controlled by the trans-membrane potential difference

Answer 16

Which of the following statements comparing transmitter-gated channels and voltage-gated channels is CORRECT?

c. Transmitter-gated channels and voltage-gated channels always have a central water-filled pore allowing ionic movement.

Question 17

Which ONE is INCORRECT for the receptors involved in fast synaptic transmission?

a. Different receptors are needed for binding different neurotransmitters.
b. They always contain a water-filled pore that acts as an ion channel.
c. They are always a protein complex made up of five identical sub-units.
d. A second messenger is not required for the post-synaptic effect.
e. These receptors can produce fast excitatory or inhibitory post-synaptic potentials.

Answer 17

Which ONE is INCORRECT for the receptors involved in fast synaptic transmission?

c. They are always a protein complex made up of five identical sub-units.

Question 18

Which one of the following is CORRECT in relation to activity at the terminal bouton?

a. Voltage-gated Ca++ channels are found only at the active zones.
b. For transmitter release the terminal must be depolarized to produce an action potential.
c. Transmitter molecules are released together with the vesicle into the synaptic cleft.
d. Docking proteins are the sites at which vesicles wait to be filled with transmitter molecules.
e. The active zone causes recycling of vesicles that may have released transmitter molecules.

Answer 18

Which one of the following is CORRECT in relation to activity at the terminal bouton?

a. Voltage-gated Ca++ channels are found only at the active zones.

Terminal Bouton = pre-synaptic terminal

b. Transmitter release is due to the influx of Calcium ions
c. Vesicles are not released with transmitter molecules
d. Docking = process during which the vesicle and pre-synaptic membrane line up in a fusion ready state
e. Only the vesicles at the active site can release transmitter molecules

Question 19

Which one of the following is CORRECT?

a. Chemical synapses produce slow voltage changes whereas electrical synapses produce slow biochemical changes.
b. Transmission at a chemical synapse depends on release of quanta of non-peptide or peptide transmitter.
c. Electrical synapses only transmit information in one direction.
d. Chemical synapses allow bidirectional flow of information through gap-junction channels.
e. Transmission at a chemical synapse is faster than at an electrical synapse.

Answer 19

Which one of the following is CORRECT?

b. Transmission at a chemical synapse depends on release of quanta of non-peptide or peptide transmitter.
.

Question 20

Which one of the following is INCORRECT in relation to transmitter release?

a. Calcium entry into the terminal bouton is essential.
b. Depolarisation of the terminal axon is necessary.
c. Each vesicle contains a similar amount (quantum) of transmitter.
d. Only docked vesicles fuse with the pre-synaptic membrane.
e. A decrease in calcium concentration in the terminal enhances transmitter release.

Answer 20

Which one of the following is INCORRECT in relation to transmitter release?

e. A decrease in calcium concentration in the terminal enhances transmitter release.

Question 21

What features best characterise a prototypical neuron?

a. A resting membrane potential of -65mV
b. The ability to generate an action potential
c. Mechanisms for action potential generation and neurotransmitter release
d. The ability to release neurotransmitter
e. Myelinated axons and unmyelinated dendrites

Answer 21

What features best characterise a prototypical neuron?

d. The ability to release neurotransmitter

Question 22

What is the role of Oligodendroglia?

a. Produce myelin, which electrically insulates axons
b. Are intimately connected with axons and dendrites to improve synaptic conduction
c. Improve conduction velocities in axons and dendrites
d. Produce myelin, which increases axonal conduction velocity by decreasing membrane resistance
e. Buffer K+ ions to help prevent excitotoxicity

Answer 22

What is the role of Oligodendroglia?

a. Produce myelin, which electrically insulates axons

c. Too vague
d. It increases membrane resistance
e. Astrocytes buffer K+ ions to help prevent excitotoxicity

Question 23

The dendrites of a neuron are

a. the cytoplasmic extensions of the cell body at which neurons receive most of their inputs.
b. the output functional component of a neuron and the sites where chemicals are released.
c. the regions of a myelinated neuron which are sheathed by Schwann cells.
d. the sites at which a neuron integrates inputs.
e. the structures that give rigidity to the cell body

Answer 23

The dendrites of a neuron are

a. the cytoplasmic extensions of the cell body at which neurons receive most of their inputs.

Question 24

What type of glial cell affects neuromodulation over long timescales by detecting and responding to neurotransmitters?

a. Oligodendroglia
b. Astrocytes
c. Microglia
d. Schwann cells
e. Ependymal

Answer 24

What type of glial cell affects neuromodulation over long timescales by detecting and responding to neurotransmitters?

b. Astrocytes

Astrocytes regulate chemical content of extracellular space, and support synaptic signalling. They are also essential in the uptake of neurotransmitters from the synaptic cleft

Question 25

At a chemical synapse: a. action potentials are produced by chemical vesicles. b. binding of chemicals to receptors causes the opening of voltage-gated vesicles in the post-synaptic cell. c. pre-synaptic terminal depolarisation ultimately causes release of chemicals from vesicles. d. transmission of activity from pre-synaptic to post-synaptic cells occurs through second messengers. e. second messengers allow the binding of vesicles to the pre-synaptic membrane.

Answer 25

At a chemical synapse: c. pre-synaptic terminal depolarisation ultimately causes release of chemicals from vesicles. a. action potentials are produced by the difference in charge across the cell membrane, not chemical vesicles b. binding of chemicals to receptors causes the opening or closing of voltage-gated vesicles in the post-synaptic cell d. transmission occurs through the release of chemicals from vesicles, modulated by astrocytes e. second messengers relays signals received on the surface of receptor cells

Question 26

The resting membrane potential is primarily set by which membrane-bound proteins? a. Two-pore potassium channels (K2P) b. Voltage gated Ca channels (CaV) c. The Na+/Ca2+ exchanger d. Voltage-gated sodium channels (NaV) e. Voltage-gated potassium channels (KV)

Answer 26

The resting membrane potential is primarily set by which membrane-bound proteins? a. Two-pore potassium channels (K2P) - generally open - contribute to K+ leak - regulate ion flow physically and chemically - help set up resting potential Voltage gated Ca channels (CaV) - only present in synapse Na+/Ca2+ exchanger - used to remove Ca from cells - powered by ATP - allow actin + myosin to relax Voltage-gated sodium channels (NaV) - closed at resting membrane potential - 3 conformations: closed: -65mV open: upon depolarisation, allow Na ions to enter cell for 1ms inactive: globular protein block passageway until cell is hyperpolarised Voltage-gated potassium channels (KV) - opens depending on membrane potential - have pore loops

Question 27

If delayed rectifier, voltage-activated K+ channels did not exist, what would happen to the membrane potential? a. A more pronounced after-hyperpolarization would be evident following an action potential b. The resting membrane potential would be higher c. The resting membrane potential would not be reached after an action potential d. The resting membrane potential would be reached, but more slowly, after an action potential e. The voltage peak during an action potential would be lower

Answer 27

If delayed rectifier, voltage-activated K+ channels did not exist, what would happen to the membrane potential? d. The resting membrane potential would be reached, but more slowly, after an action potential K+ channels are used for depolarising the membrane. Without it, the membrane would not be as depolarised after the action potential.

Question 28

In an unusual neuron that you have discovered, the ionic equilibrium potential for chloride ions is 30 mV. If synaptic inputs cause chloride ion channels to open in this neuron, what would you expect to happen to the membrane potential? a. It should move towards 30 mV b. It should become more negative c. It should move towards the resting membrane potential d. It's impossible to say without knowing the current membrane potential e. It should become more positive

Answer 28

In an unusual neuron that you have discovered, the ionic equilibrium potential for chloride ions is 30 mV. If synaptic inputs cause chloride ion channels to open in this neuron, what would you expect to happen to the membrane potential? a. It should move towards 30 mV Chloride ion channels open, hence allowing the influx of chloride ions, depolarizing the membrane until it reaches 30mV.

Question 29

In extreme cases, it is possible for the Na+/K+-ATPase pump to run in reverse. The conditions most likely to lead to this unusual scenario are: a. reduced intracellular [Na+] and increased extracellular [ATP] b. reduced intracellular [Na+] and reduced intracellular [ATP] c. increased extracellular [Na+] and increased intracellular [K+] d. increased intracellular [Na+] and increased intracellular [K+] e. an extracellular solution completely deficient in K+ ions

Answer 29

In extreme cases, it is possible for the Na+/K+-ATPase pump to run in reverse. The conditions most likely to lead to this unusual scenario are: a. reduced intracellular [Na+] and increased extracellular [ATP] Pumping K+ into the cell and Na+ out occurs during depolarisation. Doing the opposite can occur when there is increased extracellular ATP and reduce intracellular Na+. Having increased intracellular Na+ requires the pump to try to pump Na+ in. ATP is required in the pumping process.

Question 30

When measured at the synapse where they originate, excitatory post-synaptic potentials (EPSPs): a. Cannot summate, because they are all-or-none processes b. Are quantized because there is a fixed amount of neurotransmitter in each pre-synaptic vesicle c. Depend primarily on the movement of Chloride ions d. Are usually large enough to generate an action potential e. Have a peak amplitude that depends on the membrane length constant

Answer 30

When measured at the synapse where they originate, excitatory post-synaptic potentials (EPSPs): b. Are quantized because there is a fixed amount of neurotransmitter in each pre-synaptic vesicle a. They can summate, as the APs can overlap during depolarisation period c. EPSPs are due to release of neurotransmitters into post synaptic cleft d. EPSPs are depolarising, and hence prepare the cell for action potential. Sometimes one isn't enough to trigger an AP, hence requires summation e. The peak amplitude is affected by: - type and number of channels open - modulating synaptic efficacy - probability of vesicle release - inhibition * EPSPs = excitatory = Na+ * IPSPs = inhibitory = Cl-

Question 31

Comparing ionotropic and metabotropic receptors, which of the following is true: a. ionotropic receptors only allow ions to pass through, whereas metabotropic receptors can pass ions and small molecules b. metabotropic receptors are always ligand-gated, whereas ionotropic can be voltage-gated or ligand-gated c. the effects of metabotropic receptors are slower and longer lasting than those of ionotropic receptors d. metabotropic receptors bind metabolites, whereas ionotropic receptors bind or pass ions e. ionotropic receptors are inhibitory and metabotropic receptors are excitatory

Answer 31

Comparing ionotropic and metabotropic receptors, which of the following is true: c. the effects of metabotropic receptors are slower and longer lasting than those of ionotropic receptors Ionotropic - ion channel is gated by a ligand - fast and brief - typically less selective than VGC Metabotropic - receptor directly linked with ion channel - neurotrans binding activates G-protein - G-protein moves along embrane to activate ion channel/enzyme

Question 32

In order to demonstrate the quantal release of neurotransmitter, required a synapse in which a limited number of vesicles were simultaneously released from an axon terminal. To do this, it was necessary to study the phenomenon: a. using an extracellular fluid containing magnesium ions, because magnesium prevents vesicle release b. using an extracellular fluid effectively no calcium ions, because calcium drives neurotransmitter release c. in proximal synapses, where post-synaptic potentials are very small d. by stimulating axons with two closely spaced action potentials, so that most vesicles were released in response to the first action potential e. at the neuromuscular junction, because synapses at muscles normally only release a small number of neurotransmitter vesicles.

Answer 32

In order to demonstrate the quantal release of neurotransmitter, required a synapse in which a limited number of vesicles were simultaneously released from an axon terminal. To do this, it was necessary to study the phenomenon: b. using an extracellular fluid effectively no calcium ions, because calcium drives neurotransmitter release To see whether each vesicle had roughly the same amount of neurotransmitters, it must be ensured that all neurotransmitters are released under the same conditions, hence: - similar concentration of Ca ions (Ca ions drive neurotrans release) - released the first time (no overlap in AP, otherwise second time release more)

Question 33

Halorhodopsin is a light-gated chloride-ion pump that can be expressed in neurons using viral methods. Application of light with a wavelength of 570 nm causes the pump to move chloride ions into the neuron, regardless of the chemical or electrical gradient across the membrane. If light of 570 nm is shone onto a neuron expressing halorhodopsin: a. the neuron will be less likely to fire action potentials b. the neuron will have an increased probability of vesicle release c. the neuron will be more likely to fire action potentials d. the neuron will have an decreased probability of vesicle release e. changes are impossible to predict because they depend on the current membrane potential

Answer 33

Halorhodopsin is a light-gated chloride-ion pump that can be expressed in neurons using viral methods. Application of light with a wavelength of 570 nm causes the pump to move chloride ions into the neuron, regardless of the chemical or electrical gradient across the membrane. If light of 570 nm is shone onto a neuron expressing halorhodopsin: a. the neuron will be less likely to fire action potentials More chloride in the cell hyperpolarises the cell. This would make it harder to fire APs. Vesicle release depends on Ca+ ions and the Na+/Ca2+ pump

Question 34

At the post-synaptic cell, neurotransmitters produce voltage changes: a. only by binding to membrane-bound receptors that form ion channels. b. only by binding to receptors that are protein complexes made up of five sub-units. c. that are always a depolarization of the post-synaptic resting membrane potential. d. that may be a depolarization or a hyper-polarization of the post-synaptic resting membrane potential. e. through receptors that selectively allow the movement of only one ion.

Answer 34

At the post-synaptic cell, neurotransmitters produce voltage changes: d. that may be a depolarization or a hyper-polarization of the post-synaptic resting membrane potential Polarity of voltage changes depends on whether it is an EPSP or IPSP (ie, whether neurotransmitters are predominantly Na+ or Ca++), hence either a hyper/depolarisation. Some receptors allow the movement of more than one ion.

Question 35

Binding sites on receptors are a. The regions that make the receptor selective for the type of ion b. Found only on membrane-bound receptors. c. The regions where the ligand can bind to elicit a cellular response. d. Found only on receptors that form as ion channels. e. The regions where a conformational change allows G proteins to bind to the receptor.

Answer 35

Binding sites on receptors are c. The regions where the ligand can bind to elicit a cellular response. This is addressing ionotropic receptors. They do not make the receptor selective for certain types of ions. G proteins are specifically for metabotropic receptors

Question 36

You are studying a glutamatergic neuron in the central nervous system, and expect the probability of vesicular release to be low (Pr=0.1). If two action potentials (APs) arrive with a separation of 25 ms at the synapse, what would you predict to observe in association with the second action potential compared to the first: a. larger post-synaptic depolarisation, because of increased neurotransmitter release b. greater post-synaptic calcium influx, because more voltage-gated calcium channels open c. larger post-synaptic calcium influx, because of increased neurotransmitter release d. smaller post-synaptic depolarisation, because most membrane-bound neurotransmitter would already be released e. larger pre-synaptic depolarisation, because of increased calcium influx

Answer 36

You are studying a glutamatergic neuron in the central nervous system, and expect the probability of vesicular release to be low (Pr=0.1). If two action potentials (APs) arrive with a separation of 25 ms at the synapse, what would you predict to observe in association with the second action potential compared to the first: a. larger post-synaptic depolarisation, because of increased neurotransmitter release probability of neurotransmitter release on the second time = 0.9

Question 37

Which of the following statements regarding the blood-brain barrier is/are CORRECT? MORE than ONE option may be Correct. Please select ALL Correct options. a. The blood-brain barrier is made up of endothelial cells, astrocyte foot processes and tight-junctions b. The blood-brain barrier prevents all macromolecules (including glucose) from entering the brain c. The blood-brain barrier is a result of tight junctions between endothelial cells and capillaries"

Answer 37

Which of the following statements regarding the blood-brain barrier is/are CORRECT? MORE than ONE option may be Correct. Please select ALL Correct options. a,c Endothelial cells produce cerebral spinal fluid Astrocytes manage the tight junctions

Question 38

Which of the following statements relating to the meninges and cerebrospinal fluid (CSF) which act to provide a buffer in which the CNS (including the brain and spinal cord) are CORRECT? MORE than ONE option may be Correct. a. The pia mater is the outermost layer closest to the skull b. The pia mater is separated from the arachnoid space by a space filled with cerebrospinal fluid c. CSF is produced by the choroid plexus located within the ventricles d. The meninges comprise of the pia mater, dura mater and arachnoid mater

Answer 38

Which of the following statements relating to the meninges and cerebrospinal fluid (CSF) which act to provide a buffer in which the CNS (including the brain and spinal cord) are CORRECT? MORE than ONE option may be Correct. b, c, d From outer to inner: dura mater: hardest arachnoid mater: connecting pia mater: softest inner

Question 39

Functional Magnetic Resonance Imaging (fMRI) relies on regional differences in cerebral blood flow to identify localised changes in brain activity. A disadvantage of this brain imaging technique is which of the following? SELECT ALL CORRECT OPTIONS a. cerebral blood flow is only an indirect marker of activity, rather than directly visualising active cortex b. Good spatial but poor temporal resolution c. Non-invasive measure of human brain function whilst performing tasks d. cerebral blood flow decreases in response to increased activity and there is a 2-6 second delay

Answer 39

Functional Magnetic Resonance Imaging (fMRI) relies on regional differences in cerebral blood flow to identify localised changes in brain activity. A disadvantage of this brain imaging technique is which of the following? SELECT ALL CORRECT OPTIONS a, b, c fRMI is: - non invasive - good spatial resolution - poor temporal resolution

Question 40

Complex neural systems can often be represented as graphs. The study of complex neural networks comprising the human brain can be characterised by two fundamental principles guiding the organization of these networks known as functional segregation and integration. Functional segregation refers to which of the following? a. the presence of spatially distinct neuronal populations and systems that are specialized for performing certain functions b. the connections between regions defined as edges. c. the coordination of segregated elements to allow the emergence of coherent cognitive and behavioral states d. The concept that damage to a particular brain region results in specific impairments in function specific to that region

Answer 40

Complex neural systems can often be represented as graphs. The study of complex neural networks comprising the human brain can be characterised by two fundamental principles guiding the organization of these networks known as functional segregation and integration. Functional segregation refers to which of the following? a. the presence of spatially distinct neuronal populations and systems that are specialized for performing certain functions

Question 41

Electroencephalography (EEG) is a useful technique in measuring human brain function. Which of the following statements is CORRECT? a. EEG is an invasive procedure that provides a measurement of generalized electrical activity of the cerebral cortex b. EEG retains good spatial resolution but poor temporal resolution c. In EEG, small voltage fluctuations, usually a few tens of microvolts (V) in amplitude, are measured between selected pairs of electrodes d. Although invasive, EEG results in very little damage to cells

Answer 41

Electroencephalography (EEG) is a useful technique in measuring human brain function. Which of the following statements is CORRECT? c. In EEG, small voltage fluctuations, usually a few tens of microvolts (V) in amplitude, are measured between selected pairs of electrodes EEG is: - invasive - good temporal resolution - poor spatial resolution

Question 42

Following absorption of a photon by a cone photoreceptor, which of these options occurs? a. The membrane potential depolarises and glutamate release decreases b. Action potentials are produced following cell depolarisation c. The membrane potential depolarises and glutamate release increases d. The membrane potential hyperpolarises and glutamate release decreases e. The membrane potential hyperpolarises and glutamate release increases

Answer 42

Following absorption of a photon by a cone photoreceptor, which of these options occurs? d. The membrane potential hyperpolarises and glutamate release decreases photon -> ganglion cells -> bipolar cells -> rods and cones - photon excites ganglionic cells, inhibits bipolar cells - hence hyperpolarises membrane potential and decreases glutamate release

Question 43

You are walking outside on a bright, sunny day when your friend shines a flashlight into your eye. What effect would the added light have on the membrane potential of your rod photoreceptors? a. No significant change b. Depolarisation c. Hyperpolarisation d. Hyperpolarisation followed by depolarisation e. The change cannot be predicted"

Answer 43

You are walking outside on a bright, sunny day when your friend shines a flashlight into your eye. What effect would the added light have on the membrane potential of your rod photoreceptors? a. No significant change You are already in an area where it is light. Cones are working.

Question 44

Part of the eye’s function is to refract the light, so that all photons originating from the same point in space converge onto the same point of the retinal surface. The structure responsible for most of the refraction in the eye is the? a. Aqueous humor b. Focal point c. Fovea d. Lens e. Cornea

Answer 44

Part of the eye’s function is to refract the light, so that all photons originating from the same point in space converge onto the same point of the retinal surface. The structure responsible for most of the refraction in the eye is the? e. Cornea Aqueous humor = fluid between cornea and lens of eye Focal point = point of focus of light rays in eye Fovea = pit/depression in the retina at the centre of macula, contains only cone photoreceptors, specialised for high acuity vision, blind spot Lens = transparent structure between aqueous and vitreous humor, enables eye to adjust focus to different viewing distances Cornea = transparent external surface of eye

Question 45

Myopia, or short-sightedness, can be caused by which of the following? a. An eyeball that is too long, or a lens that is too weak b. An eyeball that is too short, or a lens that is too strong c. Loss of elasticity in the lens d. An eyeball that is too short, or a lens that is too weak e. An eyeball that is too long, or a lens that is too strong

Answer 45

Myopia, or short-sightedness, can be caused by which of the following? e. An eyeball that is too long, or a lens that is too strong - fixed using concave lens Hypermyopia = eyeball too short or lens is too weak - fixed using convex lens Presbyopia = farsightedness in older people - loss in elasticity in lens Astigmatism = blurry vision - due to rotational assymetries in cornia

Question 46

If a patient had a pituitary tumour that compressed the optic chiasm, how might this affect their vision? a. Loss of stereoscopic depth perception in the central visual field b. Binasal hemianopia c. Loss of the ability to perceive the central visual field d. Mildly reduced acuity in the peripheral visual field e. Complete blindness

Answer 46

If a patient had a pituitary tumour that compressed the optic chiasm, how might this affect their vision? a. Loss of stereoscopic depth perception in the central visual field Optic nerve = right behind eye - right eye right optic nerve - will see left + middle if right optic nerve damaged Optic chiasm = nerves from both eyes - decussation point - will not be able to see peripheral vision if damaged Optic tract = nerves from other eye - hence will affect either right or left field of vision - only see half

Question 47

An electrode penetration through primary visual cortex, parallel to the surface of cortex, will progressively encounter cells that show systematic changes in their preference for: a. Colour b. Receptive field size c. Orientation d. Center-surround structure e. Eye position

Answer 47

An electrode penetration through primary visual cortex, parallel to the surface of cortex, will progressively encounter cells that show systematic changes in their preference for: c. Orientation Sagittal cross section of the brain show that different types of retinal info are being kept separate at synaptic relay. Cells in same column have similar tuning properties. Cells in same row have similar orientations.

Question 48

The stereocilia on the inner hair cells: a. Contain ligand-gated Ca2+ channels b. Contain voltage-gated K+ ion channels c. Are physically coupled to the tectorial membrane d. Cause the cell to hyperpolarise when they are deflected e. Contain mechanically-gated ion channels linked by protein chains

Answer 48

The stereocilia on the inner hair cells: e. Contain mechanically-gated ion channels linked by protein chains Stereocilia are: - contain Voltage Gated Ca channels and channels for K influx (not specific to K) - linked by proteins at the tip link proteins to connect adjacent sterocilia - arranged in height order - are separate from the tectorial membrane - cause K+ influx when deflected, hence depolarisation - are non spiking (APs occur in the spiral ganglion neuron.)

Question 49

Primary auditory cortex is arranged such that preferences for sound ________ smoothly vary between neurons in adjacent columns: a. Frequencies b. Pressure levels c. Intensities d. Inter-aural level differences e. Inter-aural timing differences

Answer 49

Primary auditory cortex is arranged such that preferences for sound ________ smoothly vary between neurons in adjacent columns: a. Frequencies

Question 50

Which of the following best describe Meissner's corpuscles? a. Have relatively large receptive fields b. Display slow rates of adaptation c. Primarily sensitive to skin stretch d. The only mechanoreceptor found in glabrous skin e. Account for human sensitivity to low frequency vibrations

Answer 50

Which of the following best describe Meissner's corpuscles? e. Account for human sensitivity to low frequency vibrations - b is correct as well Meissner + Pacinian: - Hairy + glabrous - slow adapting - sustained response - larger threshold for indentation Merkel + Ruffini: - Glaborous - Fast adapting - no sustained response - smaller threshold for indentation ``` Threshold for indentation: (Largest to smallest) Ruf = Skin stretch Mer = Edges and points Mei = Lateral motion Pac = Vibration ```

Question 51

Which of the following best describe Ruffini endings? a. Have relatively small receptive fields b. Primarily sensitive to skin stretch c. The only mechanoreceptor found in glabrous skin d. Display rapid rates of adaptation e. Account for human sensitivity to low frequency vibrations

Answer 51

Which of the following best describe Ruffini endings? b. Primarily sensitive to skin stretch a,d are correct as well

Question 52

A single neuron in area 3b is described as having "replacing inhibition". This means that the stimulus that will evoke the highest rate of action potentials in this neuron is: a. pinching and holding the skin b. stretching the skin surface c. tapping the skin d. pulling on the skin e. application of the neurotransmitter GABA

Answer 52

A single neuron in area 3b is described as having "replacing inhibition". This means that the stimulus that will evoke the highest rate of action potentials in this neuron is: c. tapping the skin

Question 53

One of the defining characteristics of somatotopic organisation is that: a. processing of inputs received from Merkel disks and Meissner's corpuscles is spatially segregated b. the surface area of cortex devoted to the fingers is larger than that devoted to the entire lower limb c. neurons are more densely packed in regions of cortex representing the tip of the fingers and lips d. neurons in three adjacent cortical areas contain separate representations of the lower limb, upper limb and head e. neurons in adjacent regions of cortex represent touch stimulation applied to adjacent regions of the skin surface

Answer 53

One of the defining characteristics of somatotopic organisation is that: e. neurons in adjacent regions of cortex represent touch stimulation applied to adjacent regions of the skin surface

Question 54

If two fingers always received simultaneous and identical somatosensory stimulation, over many months we might expect that in cortical area 3b there will be: a. A region of neurons that encode another sense, such as audition or vision b. An expanded cortical representation of the two fingers c. A decrease in the surface area devoted to processing inputs from all of the fingers d. Merging of the representation of the two fingers e. An increase in the surface area devoted to processing inputs from all of the fingers

Answer 54

If two fingers always received simultaneous and identical somatosensory stimulation, over many months we might expect that in cortical area 3b there will be: d. Merging of the representation of the two fingers

Question 55

Acetylcholine causes a depolarisation at the end-plate region of skeletal muscle because it: a. Is positively charged and enters the cell b. Causes an increase in conductance for Na+ ions only. c. Causes an increase in conductance for small cations. d. Causes an increase in conductance for both cations and anions. e. Causes Calcium release from the sarcoplasmic reticulum

Answer 55

Acetylcholine causes a depolarisation at the end-plate region of skeletal muscle because it: c. Causes an increase in conductance for small cations.

Question 56

Acetylcholine esterase plays an important role in neuromuscular transmission because it: a. Transmits the depolarisation of the motor end plate to the adjacent muscle membrane. b. Rapidly terminates the action of acetylcholine by breaking it down. c. Acts in the axon terminal of motor nerves to produce acetylcholine. d. Is the second messenger responsible for opening the Na+ channels in the motor end plate e. Improves the efficiency of vesicle release and acetylcholine transmission across the synaptic cleft

Answer 56

Acetylcholine esterase plays an important role in neuromuscular transmission because it: b. Rapidly terminates the action of acetylcholine by breaking it down.

Question 57

The direct pathway in the basal ganglia: a. has a net inhibitory effect on cortex b. has glutamate as its only neurotransmitter c. follows the pathway cortex > striatum > globus pallidus > thalamus d. is inhibited by dopamine e. is critical for stopping movements in progress

Answer 57

The direct pathway in the basal ganglia: c. follows the pathway cortex > striatum > globus pallidus > thalamus Direct = facilitatory Indirect = suppresive Cortex>striatum>GPe>STN>GPi>VLo

Question 58

In the crossbridge cycle, binding of ATP immediately precedes: a. Removal of the inhibitory influence of tropomyosin and troponin. b. Formation of the actomyosin complex prior to the "power stroke". c. Removal of Ca2+ from the regulator protein troponin. d. The sliding movement of the myofilaments. e. Rapid dissociation of the actin-myosin complex

Answer 58

In the crossbridge cycle, binding of ATP immediately precedes: e. Rapid dissociation of the actin-myosin complex Crossbridge: 1. Myosin head unbound but energised 2. Actin binding site blocked by tropomyosin 3. Ca2+ binds to troponin, moves tropomyosin 4. Myosin cross-bridges bind to actin 5. Power stroke: myosin head rotates 6. ATP binding to myosin breaks AM linkage 7. Bound ATP splits, re-energising mysosin head

Question 59

It is possible, but inappropriate, to calculate a nerve conduction velocity (CV) based on a single point of stimulation using: (1) the distance between the stimulating and recording electrodes and (2) the delay between stimulation and observing an EMG signal. Using this erroneous approach, the CV calculated from stimulation at the wrist is affected to a greater degree than the elbow-stimulation CV due to an error factor associated with: a. synaptic transmission at the neuromuscular junction b. the thickness of the skin under the electrode c. the amount of fat under the electrode d. the change in axon diameters between elbow and wrist e. the amount of superficial fat at the wrist compared to the elbow

Answer 59

It is possible, but inappropriate, to calculate a nerve conduction velocity (CV) based on a single point of stimulation using: (1) the distance between the stimulating and recording electrodes and (2) the delay between stimulation and observing an EMG signal. Using this erroneous approach, the CV calculated from stimulation at the wrist is affected to a greater degree than the elbow-stimulation CV due to an error factor associated with: a. synaptic transmission at the neuromuscular junction

Question 60

Following damage to axons in the descending lateral corticospinal tract, motor reflexes: a. are initially lost, but return at an exaggerated level due to the loss of descending inhibition b. are initially lost, but return at a reduced level due to increased descending inhibition c. are initially unaffected, but eventually lost due to the death of lower motor neurons d. are immediately lost and do not return due to the the death of lower motor neurons e. are unaffected

Answer 60

Following damage to axons in the descending lateral corticospinal tract, motor reflexes: a. are initially lost, but return at an exaggerated level due to the loss of descending inhibition

Question 61

The main factor that contributes to electrical-stimulation thresholds for the ulnar nerve that differ both between individuals and stimulation locations is: a. the axon diameter b. how superficial the nerve is c. fatigue d. how far the stimulation point is from a Node of Ranvier e. the temperature

Answer 61

The main factor that contributes to electrical-stimulation thresholds for the ulnar nerve that differ both between individuals and stimulation locations is: b. how superficial the nerve is How skin deep the nerve is

Question 62

During neuromuscular transmission: a. there is an increase in the permeability of the motor end plate membrane to Ca2+. b. acetylcholine binds to receptors on the motor end plate membrane. c. Ca2+ is released from vesicles located in the motor nerve terminal. d. acetylcholine esterase depolarises the muscle membrane adjacent to the motor end plate. e. re-uptake of acetylcholine into the motor nerve terminal terminates the action of this transmitter

Answer 62

During neuromuscular transmission: b. acetylcholine binds to receptors on the motor end plate membrane. Acetylcholine is broken down by an enzyme

Question 63

Which of the following should have the fastest conduction velocity? a. An unmyelinated, small diameter nerve b. An unmyelinated, large diameter nerve c. A myelinated, small diameter nerve d. A myelinated, large diameter nerve e. They would all have the same conduction velocity

Answer 63

Which of the following should have the fastest conduction velocity? d. A myelinated, large diameter nerve

Question 64

Fast glycolytic (Type IIB) skeletal muscle fibres: a. are considerably smaller than slow oxidative (Type I) fibres. b. are found mostly in the large postural muscles. c. contain more mitochondria than slow contracting fibres because they use more ATP. d. have a higher rate of energy (ATP) use and fatigue more rapidly than slow oxidative fibres. e. can only obtain ATP from glucose

Answer 64

Fast glycolytic (Type IIB) skeletal muscle fibres: d. have a higher rate of energy (ATP) use and fatigue more rapidly than slow oxidative fibres. Can obtain ATP from both glycogen stores and mitochondria (fewer)

Question 65

Rapid variations in the force generated by a muscle can be produced by: a. varying the firing rate of gamma motor neurons b. changing the number of muscle fibers innervated by a lower motor neuron c. reaching tetanus d. changing the number of recruited motor units e. taking anabolic steroids

Answer 65

Rapid variations in the force generated by a muscle can be produced by: d. changing the number of recruited motor units gamma motor neurons control muscle contraction in response to external forces acting on muscle, and is hence uncontrolled

Question 66

In the prac lab, when delivering a single stimulus pulse to the ulnar nerve, if the current is increased, the amount of force generated eventually plateaus. The best explanation for this observation is that: a. a single action potential can only recruit a single motor unit b. all of the motor units in the muscle have been activated c. all of the small motor units have been activated (large motor units are not activated by a single action potential) d. all of the large motor units have been activated (small motor units are not activated by a single action potential) e. there is too much resistance in the subcutaneous fat

Answer 66

In the prac lab, when delivering a single stimulus pulse to the ulnar nerve, if the current is increased, the amount of force generated eventually plateaus. The best explanation for this observation is that: c. all of the small motor units have been activated (large motor units are not activated by a single action potential) smaller motor units are recruited first, then larger motor units. This causes summation of APs, which create a plateau in the force generated

Question 67

Imagining a sequence of movements would mostly be associated with an increase in activity in: a. primary motor cortex b. premotor cortex c. supplementary motor area d. association cortex e. primary motor cortex and supplementary motor area

Answer 67

Imagining a sequence of movements would mostly be associated with an increase in activity in: c. supplementary motor area SMA is used for memory Pre-SMA is used for learning

Question 68

The main function of the primary motor cortex is to: a. Plan and select movements b. Control posture in preparation for movements c. Execute a plan of movements formulated in the basal ganglia and cerebellum d. Specify movement of combinations of muscles but not individual muscles e. Control the contractions of individual muscles

Answer 68

The main function of the primary motor cortex is to: d. Specify movement of combinations of muscles but not individual muscles SMA plans and selects movements Cerebellum executes and monitors movements (coordinate + refine)

Question 69

In skeletal muscle, the mechanism of contraction involves: a. Shortening of the actin and myosin filaments so that the Z lines are pulled closer together. b. Cyclic interactions between myosin crossbridges and the actin filament c. The Z lines pushing on the thin filaments to make them slide over the thick filaments. d. ATP forming bridges linking the actin and myosin filaments. e. overcoming the elastic resistance of titin filaments

Answer 69

In skeletal muscle, the mechanism of contraction involves: b. Cyclic interactions between myosin crossbridges and the actin filament a,c. It is not really centered around Z disks d. the myosin head links with actin, the ATP only provides the energy to do so e. titin provide elasticity for muscles

Question 70

In general, motor units with small cell bodies: a. are activated when large force generation is required b. are all activated simultaneously c. produce the smallest amount of force d. are only found in small muscles, as required for moving the fingers and eyes e. reach tetanus at the highest frequencies

Answer 70

In general, motor units with small cell bodies: c. produce the smallest amount of force

Question 71

Within an individual motor unit a. the muscle fibres are all of the same type. b. a graded contraction can be produced as the action potential travelling down the axon excites progressively more muscle fibres. c. the contractile work can be shared by switching different muscle fibres within the motor unit on and off at different times. d. the only way that the contraction strength can be graded is by changing the length of the muscle fibres. e. the main determinant of contraction strength is how many axons within that motor unit are activated

Answer 71

Within an individual motor unit a. the muscle fibres are all of the same type.

Question 72

In the prac class, you observed the EMG while making an isometric contraction. We would normally expect that: a. only large motor units were recruited, because this is an isometric contraction b. only small motor units were recruited, because this is an isometric contraction c. small motor units have smaller action potentials than large motor units d. small motor units are recruited before large motor units e. we only observe activity from the large motor units, because they generate more electrical activity

Answer 72

In the prac class, you observed the EMG while making an isometric contraction. We would normally expect that: d. small motor units are recruited before large motor units isometric = changing length of muscle when force is applied

Question 73

A motor unit comprises: a. all the muscle fibres within a given muscle b. all the neurons going into an individual section of the body c. a motor neuron and the muscle fibres it innervates d. an upper and lower motor neuron e. one muscle fibre and all of the motor neurons that innervate it

Answer 73

A motor unit comprises: c. a motor neuron and the muscle fibres it innervates

Question 74

In response to two closely-spaced (\50 ms), supra-threshold electrical pulses delivered to the ulnar nerve, it is likely that any individual myosin cross-bridge will bind to the actin filament: a. zero times b. once c. twice d. more than twice

Answer 74

In response to two closely-spaced (\50 ms), supra-threshold electrical pulses delivered to the ulnar nerve, it is likely that any individual myosin cross-bridge will bind to the actin filament: d. more than twice 1ms per AP

Question 75

Parkinson’s disease is characterised by reduced movement initiation, slow movements, rigidity and resting tremor. This is caused by: a. increased serotonin production in the substantia nigra, which is part of the cerebellum b. decreased dopamine production in the substantia nigra, which is part of the cerebellum c. increased dopamine production in the substantia nigra, which is part of the basal ganglia d. decreased dopamine production in the substantia nigra, which is part of the basal ganglia e. decreased serotonin production in the substantia nigra, which is part of the basal ganglia

Answer 75

Parkinson’s disease is characterised by reduced movement initiation, slow movements, rigidity and resting tremor. This is caused by: d. decreased dopamine production in the substantia nigra, which is part of the basal ganglia Substantia nigra is a part of the basal ganglia. Dopamine is used to treat Parkinson's.

Question 76

A practical pharmaceutical strategy for treating Parkinson's disease is to: a. inject dopamine directly into the bloodstream b. inject dopamine antagonists directly into the brain c. inhibit the reuptake of dopamine d. inject human growth hormone, which stimulates regrowth of the basal ganglia e. surgically lesion the substantia nigra

Answer 76

A practical pharmaceutical strategy for treating Parkinson's disease is to: a. inhibit the reuptake of dopamine

Question 77

In the lab class, as the rate of stimulation to the ulnar nerve increases, greater movement of the finger and hand is observed. This is an example of a. Summation b. Twitch c. Phasic Contraction d. Reflex e. EMG

Answer 77

In the lab class, as the rate of stimulation to the ulnar nerve increases, greater movement of the finger and hand is observed. This is an example of a. Summation

Question 78

The sarcoplasmic reticulum (SR) is best described as: a. Excitable cell membrane that encloses the muscle fiber. b. Extensive intracellular sac containing calcium ions. c. System of tubules that bring the action potential deep inside the muscle fiber. d. Voltage-sensitive channels. e. Site of muscle protein synthesis.

Answer 78

The sarcoplasmic reticulum (SR) is best described as: b. Extensive intracellular sac containing calcium ions.

Question 79

The surface area of primary motor cortex devoted to an individual myotatic unit is most closely related to: a. the number of muscles associated with the corresponding joint b. the volume of the muscles in that myotatic unit c. the range of force that the muscles can generate d. the degree of fine control of the muscles e. the surface area of the muscles

Answer 79

The surface area of primary motor cortex devoted to an individual myotatic unit is most closely related to: d. the degree of fine control of the muscles

Question 80

Electromyography (also known as surface electromyography) is a. A technique for evaluating and recording the electrical activity produced by skeletal muscle b. A technique for evaluating and recording the electrical activity produced by cardiac muscle c. able to isolate the action potentials originating from a single muscle fibre d. Used for measuring activity in motorneurons associated with a single nerve e. used for quantifying force generation in muscle

Answer 80

Electromyography (also known as surface electromyography) is d. A technique for evaluating and recording the electrical activity produced by skeletal muscle

Question 81

Tetanic muscle contractions occur: a. In response to single action potential inputs b. In response to multiple closely spaced action potentials c. In response to multiple widely spaced action potentials d. In response to fatigue e. In response to action potential summation

Answer 81

Tetanic muscle contractions occur: b. In response to multiple closely spaced action potentials

Question 82

The forces generated in association with delivering supra-threshold ulnar nerve stimulation at 500 Hz versus 600 Hz would be: ``` a. almost identical b higher with 500 Hz stimulation c. higher with 600 Hz stimulation d. initially higher with the 600 Hz stimulation, but then identical e. it's impossible to say ```

Answer 82

The forces generated in association with delivering supra-threshold ulnar nerve stimulation at 500 Hz versus 600 Hz would be: a. almost identical

Question 83

With reference to the length-tension relationship of skeletal muscle, one length is "optimal" because a. A fully fused tetanic contraction can produce maximum force. b. The separation between adjacent Z-lines is at its maximum. c. Twitch and tetanic contractions produce the same force. d. The thin filaments from either end of the sarcomere are overlapping each other. e. The passive tension in the resting muscle is at a maximum.

Answer 83

With reference to the length-tension relationship of skeletal muscle, one length is "optimal" because a. A fully fused tetanic contraction can produce maximum force.

Question 84

The role of the transverse tubules (T-tubules) in skeletal muscle is to: a. provide a means of rapidly transmitting the action potential into the central portions of the muscle fibre. b. serve as a storage site for Ca2+. c. connect the sarcomeres end-to-end. d. refill the sarcoplasmic reticulum with Ca2+ after it has been released. e. allow for nutrients to be carried into the cell

Answer 84

The role of the transverse tubules (T-tubules) in skeletal muscle is to: a. provide a means of rapidly transmitting the action potential into the central portions of the muscle fibre.

Question 85

The correct order of time-averaged force generation, from smallest to largest is: a. single twitch, unfused tetanus, fused tetanus. b. single twitch, fused tetanus, unfused tetanus. c. single twitch, tetanus (fused tetanus and unfused tetanus generate the same amount of force) d. tetanus, single twitch (fused tetanus and unfused tetanus generate the same amount of force) e. fused tetanus, unfused tetanus, single twitch f. There is no ordering - fused tetanus, unfused tetanus and a single twitch all generate the same force.

Answer 85

The correct order of time-averaged force generation, from smallest to largest is: a. single twitch, unfused tetanus, fused tetanus.

Question 86

The flocculonodular lobe of the cerebellum (vestibulocerebellum) would be most heavily involved in which type of movement: a. learning to play tennis b. walking on a tight-rope c. initiating a walking movement d. playing computer games e. lying supine

Answer 86

The flocculonodular lobe of the cerebellum (vestibulocerebellum) would be most heavily involved in which type of movement: b. walking on a tight-rope vestibulocerebellum is linked with balance and gait

Question 87

The ANS A. is an automatic control system, with no connection to the conscious system. B. has pairs of nerves emanating from all segments of the spinal cord. C. preganglionic cell bodies reside in the ventral horns of the spinal cord. D. is broadly divided into sympathetic and parasympathetic divisions. E. uses acetylcholine as the neurotransmitter in all organs, and flexibility is achieved by many different receptors for this transmitter.

Answer 87

The ANS D. is broadly divided into sympathetic and parasympathetic divisions.

Question 88

Pain from the intestine passes along nerves which: A. pass into the thoracic segments 7-9 of the spinal cord. B. synapse in the sympathetic chain ganglia. C. accompany the vagus nerve into the brain D. pass through the ventral horn. E. None of the above are correct.

Answer 88

Pain from the intestine passes along nerves which: C. accompany the vagus nerve into the brain vagus nerve = parasympathetic control of heart, lungs and digestive tract

Question 89

Which statement is INCORRECT? The excitatory synaptic potential (ESP) in autonomic ganglia: A. results from the release of acetylcholine. B. results from the activation of nicotinic receptors. C. can piggyback on a previous ESP to reach threshold for an action potential. D. can be involved in integration within the ANS. E. is always sufficiently large to give rise to an action potential in the post-ganglionic neuron.

Answer 89

Which statement is INCORRECT? The excitatory synaptic potential (ESP) in autonomic ganglia: E. is always sufficiently large to give rise to an action potential in the post-ganglionic neuron. ESP are from acetylcholine acting on nicotinic (ionotropic) receptros in the post ganglionic neurons

Question 90

Which is NOT TRUE of autonomic neurons in effector tissues (smooth muscle, glands etc)? A. Ca2+ influx into the prejunctional varicosity is required for neurotransmission. B. The distance between prejunctional varicosities and effector tissue cells can be large. C. Extrajunctional receptors are the major contributors to the responses in target tissue cells. D. Second messengers systems have important roles in the responses in target tissue cells. E. Acetylcholine (ACh) is the major neurotransmitter released in target tissues by neurons of both the sympathetic and parasympathetic divisions of the ANS

Answer 90

Which is NOT TRUE of autonomic neurons in effector tissues (smooth muscle, glands etc)? E. Acetylcholine (ACh) is the major neurotransmitter released in target tissues by neurons of both the sympathetic and parasympathetic divisions of the ANS Extrajunctional receptors can be located anywhere in the muscle membrane, inside or outside neuromuscular junction. They are needed as the NTs are released everywhere, hence they need to be very sensitive.

Question 91

Which ONE of the following statements about noradrenergic vasoconstrictor nerves is CORRECT? A. They are distributed only to the skin and muscles of the trunk and limbs. B. Release of catecholamines from their terminals contributes to the circulating blood levels of adrenaline. C. They are important in redistributing blood following blood loss. D. Their ganglion cell bodies are found mainly in the dorsal horn ganglia. E. Their role in temperature regulation is insignificant.

Answer 91

Which ONE of the following statements about noradrenergic vasoconstrictor nerves is CORRECT? C. They are important in redistributing blood following blood loss. noradrenergic vasoconstrictor nerves are release cotransmitters to decrease skin blood flow, increase activity during cold exposure

Question 92

Activation of the sympathetic division of the ANS would produce all of the following EXCEPT A. an increase in the force of beating of the heart. B. dilation of the pupil. C. a reduction in blood flow to the skin. D. a decrease in blood flow to skeletal muscle. E. release of glucose from the liver

Answer 92

Activation of the sympathetic division of the ANS would produce all of the following EXCEPT D. a decrease in blood flow to skeletal muscle.

Question 93

A person is treated with a dose of atropine sufficient to block peripheral muscarinic receptors. Which ONE of the following events would occur? A. Parasympathetic activation would cause the heart to cease beating. B. Blood pressure would decrease markedly due to the action of the parasympathetic nerves on skin blood vessels. C. Moderate exercise would become impossible because the blood supply to skeletal muscles can no longer be increased by any means. D. There would be a marked decrease in sympathetic activity throughout the body. E. Saliva secretion would cease.

Answer 93

A person is treated with a dose of atropine sufficient to block peripheral muscarinic receptors. Which ONE of the following events would occur? E. Saliva secretion would cease. atropine blocks muscarinic receptors (and Ach from reaching them). It would increase blood pressure, decrease saliva secretion etc. Body is in flight mode, sympathetic system kicks in.

Question 94

Noradrenaline: A. only activates α-adrenoceptors. B. only activates β-adrenoceptors. C. action is terminated mainly by reuptake into the neuron from which it was released. D. is the principal product of the adrenal gland. E. is the neurotransmitter responsible for penile erection.

Answer 94

Noradrenaline: C. action is terminated mainly by reuptake into the neuron from which it was released. Noradrenaline can be synthesised from dopamine

Question 95

Which ONE of the following is NOT TRUE of the neurotransmitter nitric oxide (NO)? A. NO is synthesized from the amino acid L-arginine. B. NO is stored in vesicles in the terminal varicosities. C. A rise in cytoplasmic calcium is required for the synthesis of NO. D. NO passes directly across the cell membrane with considerable ease. E. Vascular smooth muscle is relaxed by NO.

Answer 95

Which ONE of the following is NOT TRUE of the neurotransmitter nitric oxide (NO)? B. NO is stored in vesicles in the terminal varicosities. NO is synthesized from the get go, and is very lipid soluble, hence it passes through the membrane. It has a short half life.

Question 96

Severe disability of the ANS would A. slow visual accommodation. B. impair the ability to jump out of bed rapidly. C. cause erectile dysfunction. D. result in instability of blood pressure E. all of the above.

Answer 96

Severe disability of the ANS would E. all of the above.