IMSPQ F2 - 15 Juni 2025

Which characteristic of chemical synapses ensures that nerve impulses are transmitted in a single direction—from the presynaptic neuron to the postsynaptic neuron?

• Saltatory conduction

• Bidirectional flow of ions

• Myelination of axons

• One-way conduction

• Continuous conduction

Why are chloride ions (Cl⁻) unable to pass through cation-selective ion channels?

• Chloride ions are too large to fit through the open channel pore.

• Chloride ions are blocked by the positive charges lining the channel.

• The cation channel lacks a hydration shell to support anion passage.

• The negative charges lining the channel repel chloride ions.

• Chloride ions require ATP-driven transport, not passive diffusion.

Which of the following is classified as a class III neurotransmitter (amino acid) found in the nervous system?

• Histamine

• Acetylcholine

• ATP

• Norepinephrine

• Glycine

Which of the following correctly lists a mechanoreceptor, a nociceptor, and a chemoreceptor, respectively?

• Pacinian corpuscle, Ruffini ending, adrenal medulla

• Free nerve ending, Meissner’s corpuscle, olfactory bulb

• Merkel disc, nociceptive C fibers, pineal gland

• Meissner’s corpuscle, muscle spindle, hypothalamic osmoreceptors

• Krause’s corpuscle, free nerve ending, aortic and carotid bodies

Which of the following sensory fiber groups is characterized by being unmyelinated?

• Group Ia

• Group Ib

• Group II

• Group III

• Group IV

Which of the following best describes divergence in a neuronal pool?

• Multiple inputs to one neuron

• One input to many outputs

• One neuron inhibits itself

• Lateral inhibition

• Recurrent facilitation

Which tactile receptor is less rapidly adapting and responds best to low-frequency vibration?

• Meissner’s corpuscle

• Pacinian corpuscle

• Merkel disc

• Free nerve ending

• Ruffini ending

Which of the following neurotransmitter pairs are involved in the central analgesia system?

• Dopamine and glutamate

• Enkephalin and serotonin

• Acetylcholine and histamine

• Norepinephrine and GABA

• Substance P and glutamate

Uneven curvature of the cornea causes light to refract unevenly, leading to visual distortion. This condition is called ______ and is corrected with a ______.

• Myopia, concave lens

• Hyperopia, convex lens

• Astigmatism, cylindrical lens

• Presbyopia, bifocal lens

• Glaucoma, beta-blocker drops

What is the condition of the eye in which parallel light rays from distant objects are focused exactly on the retina without the need for accommodation?

• Myopia

• Hyperopia

• Astigmatism

• Emmetropia

• Presbyopia