Understanding Neuronal Function and Synaptic Transmission

Posted on Feb 20, 2025 in Human Biology

SOL.II

  1. Neurons are polarized cells because they present a dendritic domain and an axonal domain.
  2. With respect to the Action Potential (AP): It is the electrical signal for the propagation of neuronal information.
  3. Regarding myelin: Its function (F(X)) is to accelerate the speed of nerve impulse propagation.
  4. Neuronal circuits: Endings are formed by axons and dendrites/synapses and glial cell prolongations. A simple example of a neuronal circuit is the patellar reflex.
  5. The Nervous System (NS): This is formed by the Central Nervous System (CNS), forebrain, brainstem, and cerebellum. The Sympathetic Nervous System (SNS) and the Parasympathetic Nervous System are part of the autonomic system.
  6. If you want to know if a neuron synthesizes a neurotransmitter (NT): Look at the synaptic buttons.
  7. If we cut a segment of a neuron’s axon: The nerve impulse is not propagated.
  8. Which is *not* a stimulus for the activation of ion channels?: Endocytosis.
  9. The equilibrium potential of an ion: Is determined by its concentration gradient and electrical gradient.
  10. The resting potential or membrane potential of a cell changes if: The resting K+ channels that are always open are blocked, the number of negatively charged proteins in the cell’s cytoplasm decreases, or the Na+/K+ pump is blocked.
  11. The inability to generate another AP during the refractory period is due to: A high conductivity of K+ and a large number of inactive Na+ channels.
  12. If a neuron is stimulated in the presence of voltage-sensitive K+ channel blockers: The neuron repolarizes slowly or the neuron does not hyperpolarize.
  13. If membrane vesicle recycling did not exist in the axon terminal: The speed of propagation of the nerve impulse would be much slower.
  14. A snake bite blocks the Na+/K+ ATPase: The Na+/K+ concentration gradient is not reestablished, which prevents hyperpolarization.
  15. If the extracellular Na+ concentration decreases considerably: The magnitude of the AP is lower and the length of the AP increases.
  16. Of the following processes and cellular components, which cause the difference in membrane potential?: The Gibbs-Donnan equilibrium and ion pumps.
  17. The increased speed of impulse conduction through saltatory conduction is due to: The absence of voltage-gated channels in the nodes of Ranvier and the distribution of voltage-gated Na+ and K+ channels.
  18. The simple, accurate, and complete definition of AP is: A rapid and transient change in the resting potential due to the activation of ion channels.
  19. Electrical synapses: Occur in cells that are in physical contact and allow for synchronization.
  20. Of the following events, which occur in chemical synapses?: The arrival of the AP at the presynaptic terminal.
  21. Regarding the synthesis and transport of NTs, it is true that: Enzymes synthesize small-molecule NTs, neuropeptides undergo final proteolytic processing, and B-endorphin undergoes axonal transport.
  22. Regarding NT receptors, it is true that: Metabotropic receptors activate G proteins.
  23. If a blocker of acetylcholinesterase and an acetylcholine agonist are added to cultured neurons: The degradation of acetylcholine is enhanced, and acetylcholine competes with the agonist for binding to its receptor.
  24. Which of the following strategies allows for a decrease in synaptic efficiency?: Enhancing the reuptake of the NT by the presynaptic neuron.
  25. Large dense-core synaptic vesicles: May contain adrenaline and catecholamines.
  26. The quantal release of NTs means that: All merged synaptic vesicles release a determined number of NT molecules.
  27. If the reversal potential for K+ and Cl- is -90mV: If the membrane potential becomes more positive, K+ will exit the cell and Cl- will enter the cell. If the conductivity of Cl- and K+ increases, the membrane hyperpolarizes.
  28. The release of NTs from receptors is related to: Increased frequency of APs.