PSY 627 ACTUAL TEST PAPER 2026
QUESTIONS AND SOLUTIONS GRADED A+
●● What is axoplasmic transport?
Answer: The process that propels messages along the length of the axon.
●● What is anterograde transport?
Answer: Transport of substances toward the terminal button.
●● What is retrograde transport?
Answer: Transport of substances toward the soma.
●● What role do microglia play in the nervous system?
Answer: They act as phagocytes and protect the brain, functioning as
immune cells in the CNS.
●● What is the function of oligodendrocytes?
Answer: They support axons and myelinate the CNS.
●● What are Schwann cells responsible for?
Answer: They provide one segment of myelin and myelinate the PNS.
,●● What is the role of astrocytes?
Answer: They provide nutrients, perform phagocytosis, form scar tissue,
and maintain chemical concentration.
●● How do astrocytes assist in energy metabolism?
Answer: They receive glucose, break it down to lactate using ATP, and
release lactate for neurons to use as energy.
●● What happens during regeneration after peripheral nerve injury?
Answer: Normal neuron degeneration occurs, with Schwann cells
cleaning debris and aiding in axonal sprouting and reconnection.
●● Why can damage to an axon in the CNS not be repaired?
Answer: Astrocytes produce scar tissue and send chemical signals to
stop sprouting.
●● What is saltatory conduction?
Answer: The conduction of action potentials by myelinated axons,
jumping from node to node.
●● What is Multiple Sclerosis (MS)?
Answer: An autoimmune demyelinating disease where the immune
system attacks the myelin sheath of axons in the CNS.
, ●● What is the blood-brain barrier (BBB)?
Answer: A selectively permeable barrier that regulates the composition
of extracellular fluid.
●● What is the area postrema?
Answer: A region where the blood-brain barrier is weak, which detects
toxic substances and can induce vomiting.
●● What is the resting potential of an axon?
Answer: -70 mV.
●● What is depolarization?
Answer: The process of moving the membrane potential toward 0.
●● What is hyperpolarization?
Answer: The process of moving the membrane potential to a more
negative value.
●● What is the threshold of excitation?
Answer: The set point that must be reached to produce an action
potential.
●● What occurs during an action potential?
QUESTIONS AND SOLUTIONS GRADED A+
●● What is axoplasmic transport?
Answer: The process that propels messages along the length of the axon.
●● What is anterograde transport?
Answer: Transport of substances toward the terminal button.
●● What is retrograde transport?
Answer: Transport of substances toward the soma.
●● What role do microglia play in the nervous system?
Answer: They act as phagocytes and protect the brain, functioning as
immune cells in the CNS.
●● What is the function of oligodendrocytes?
Answer: They support axons and myelinate the CNS.
●● What are Schwann cells responsible for?
Answer: They provide one segment of myelin and myelinate the PNS.
,●● What is the role of astrocytes?
Answer: They provide nutrients, perform phagocytosis, form scar tissue,
and maintain chemical concentration.
●● How do astrocytes assist in energy metabolism?
Answer: They receive glucose, break it down to lactate using ATP, and
release lactate for neurons to use as energy.
●● What happens during regeneration after peripheral nerve injury?
Answer: Normal neuron degeneration occurs, with Schwann cells
cleaning debris and aiding in axonal sprouting and reconnection.
●● Why can damage to an axon in the CNS not be repaired?
Answer: Astrocytes produce scar tissue and send chemical signals to
stop sprouting.
●● What is saltatory conduction?
Answer: The conduction of action potentials by myelinated axons,
jumping from node to node.
●● What is Multiple Sclerosis (MS)?
Answer: An autoimmune demyelinating disease where the immune
system attacks the myelin sheath of axons in the CNS.
, ●● What is the blood-brain barrier (BBB)?
Answer: A selectively permeable barrier that regulates the composition
of extracellular fluid.
●● What is the area postrema?
Answer: A region where the blood-brain barrier is weak, which detects
toxic substances and can induce vomiting.
●● What is the resting potential of an axon?
Answer: -70 mV.
●● What is depolarization?
Answer: The process of moving the membrane potential toward 0.
●● What is hyperpolarization?
Answer: The process of moving the membrane potential to a more
negative value.
●● What is the threshold of excitation?
Answer: The set point that must be reached to produce an action
potential.
●● What occurs during an action potential?
