PHSL101 Quiz 2025

What is the resting membrane potential of neurons maintained by?

• Chemically-gated Na+ Channels

• Chemically-gated K+ channels

• Na+/K+ ATPase pump

• Na+/H+ ATPase pump

Repolarisation of an activated neuron does not include:

• Shifting membrane potential towards resting levels

• Opening of voltage-gated K+ channels

• Opening of voltage-gated Na+ channels

• Inactivation of voltage-gated Na+ channels

Which statement is TRUE about the refractory period?

• It is possible to fire another action potential during this time if the stimulus is larger-than-normal

• Chemically-gated K+ channels are activated, so another action potential is possible

• Chemically-gated Na+ channels are inactivated, so another action potential is impossible

• Voltage-gated Na+ channels are open, so another action potential is possible

Which statement is INCORRECT about axon myelination?

• Myelin sheathes the axon

• Schwann cells aid in the myelination of axons

• Myelin slows down the conduction of action potentials along the axon

• Myelin increases the speed of conduction of action potentials.

In the image, cell A is a _________ neuron and cell B is a ________ neuron.

• Presynaptic; Postsynaptic

• Postsynaptic; Presynaptic

• Soma; Axon

• Dendrite; Soma

Which of the following is INCORRECT regarding the axon hillock:

• It is a site of summation of local potentials

• It is where the threshold for action potential firing can occur

• It requires ATP

• Local potentials have to occur within the same space and time.

Which of the following ions stimulates neurotransmitter release?

• Calcium

• Sodium

• Potassium

• Magnesium

The Neuromuscular Junction are made up of the following EXCEPT:

• Axon terminal of motor neuron

• Synaptic cleft

• Post-synaptic sarcolemma membrane

• T-tubule

Which of the following is NOT a source of ATP production for muscle?

• Anaerobic pathways

• Creatine phosphate shuttling

• Caffeine

• Aerobic pathways

The detachment of the actin/myosin cross-bridge is triggered by:

• Calcium ions

• The hydrolysis of ATP

• The attachment of ATP to myosin heads

• Repolarisation of T-tubules