Neurons carry messages through

Appeared in: RUHS, Jaipur, M.Sc Nursing Entrance Exam-2022

Explanation

The axon is the long, slender projection of a neuron that is specialized to conduct electrical impulses.
This electrical signal, known as an action potential, is the 'message' that travels from the cell body, through the axon, to the axon terminals.
This process of conduction is the primary way information is transmitted over distances within the nervous system.

Option A: Neurotransmitters are chemical messengers. They are released from the axon terminal of one neuron to transmit the signal across the synaptic gap to the next neuron. They do not carry the message through the neuron itself.
Option B: A synapse is the specialized junction or small gap between two neurons. It is the site of transmission, not the structure that conducts the impulse through the cell.
Option D: Dendrites are the branch-like extensions of a neuron that receive signals from other neurons and conduct them towards the cell body. They are input structures, whereas the axon is the output structure.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Structure and function of a neuron as background academic context rather than a clinical decision trigger.
Understanding axon function is critical in demyelinating diseases like Multiple Sclerosis (MS), where damage to the myelin sheath surrounding axons slows or blocks nerve impulses, leading to a wide range of neurological symptoms.
Local anesthetics, such as lidocaine, work by blocking sodium channels on the axon's membrane. This action prevents the generation and conduction of action potentials, thereby blocking the transmission of pain signals.
What if? If a patient has a condition that specifically damages dendrites (dendritopathy), they would have difficulty receiving signals from other neurons, leading to a breakdown in neural circuit communication, even if the axons are healthy.

How to Approach the Question

This is a factual recall question testing fundamental knowledge of neuroanatomy.
Identify the keywords in the question: 'Neurons' (nerve cells) and 'carry messages through'.
The phrase 'carry messages through' implies conduction along the length of a single cell, not reception of a signal or transmission between cells.
Evaluate each option's primary function in this context.
Dendrites receive signals and bring them to the cell body.
Synapses and neurotransmitters are involved in passing the signal between cells.

Concept Tested & Keywords

QPvwOeAY978cdBurRpZBAc

E6 Psychology Baron Misra 5e Part 1 pp. 61-63, 62-64

E6 Psychology Morgan King 9e Part 1 p. 65-67

Practise the full RUHS, Jaipur, M.Sc Nursing Entrance Exam-2022

Attempt every question from this paper in a timed mock, then review the full solution for each one.