In the human nervous system, what is the name of the fundamental excitable cell that receives, integrates, and transmits nerve impulses?

Introduction / Context:
The nervous system is responsible for sensing stimuli, processing information, and coordinating responses throughout the body. This complex communication network is built from specialised cells that can generate and conduct electrical impulses. Understanding the name and role of the basic excitable cell in this system is a key concept in biology and physiology. This question asks you to identify that fundamental excitable cell type.

Given Data / Assumptions:

• We are dealing with the nervous system and nerve impulses.
• Options include nephron, axon, neuron, dendrite, and glial cell.
• We assume an understanding of the difference between whole cells and cell parts.
• We also assume knowledge that some cells in the nervous system support others but do not conduct impulses themselves.

Concept / Approach:
The fundamental excitable cell of the nervous system is the neuron (also called a nerve cell). A neuron has three main parts: the cell body (soma), dendrites, and axon. Dendrites receive incoming signals, the cell body integrates them, and the axon conducts the nerve impulse away from the cell body toward other neurons or effector cells such as muscles and glands. Neurons generate action potentials and are specialised for rapid communication. By contrast, a nephron is the functional unit of the kidney, not the nervous system. Axon and dendrite are parts of a neuron, not separate excitable cells. Glial cells support, insulate, and nourish neurons, and while important, they are not the primary impulse-conducting cells.

Step-by-Step Solution:
Step 1: Identify that the question asks for a fundamental excitable cell in the nervous system, not just a structure. Step 2: Recall that a neuron is the specialised cell that can generate and propagate action potentials. Step 3: Recognise that axons and dendrites are components of a neuron; they are not whole cells by themselves. Step 4: Note that glial cells (neuroglia) support neurons structurally and metabolically, but most glial cells do not generate action potentials in the same way neurons do. Step 5: Observe that nephron belongs to the excretory system as the functional unit of the kidney and is irrelevant here. Step 6: Conclude that neuron is the correct term for the fundamental excitable cell of the nervous system.

Verification / Alternative check:
Neuroscience references describe the nervous system as a network of neurons and supporting glial cells. Illustrations show neurons as cells with branching dendrites and long axons that conduct electrical impulses. The action potential is defined as a rapid, temporary change in membrane potential that travels along the axon. Nephrons, by contrast, appear in diagrams of kidney structure. Dendrites and axons are always labelled as parts of a neuron. This consistent terminology confirms that neuron is the correct answer.

Why Other Options Are Wrong:
Option A: Nephron is the basic functional unit of the kidney in the urinary system and has no direct role in nerve impulse transmission. Option B: Axon is a part of a neuron that conducts impulses away from the cell body but is not a complete cell. Option D: Dendrite is a branched extension of the neuron that receives signals, again not a separate excitable cell. Option E: Glial cell provides support, insulation, and protection for neurons; although important, it is not the fundamental impulse-conducting cell.

Common Pitfalls:
Learners sometimes confuse axons or dendrites with entire cells because they are emphasised in structural diagrams. Another pitfall is mixing up nephron and neuron due to similar spelling. To avoid such confusion, remember that the suffix "ron" appears in both, but context matters: neurons in the nervous system and nephrons in the kidney. It also helps to recall that axon and dendrite are labelled as parts in neuron diagrams, not as separate cells.

Final Answer:
The fundamental excitable cell in the nervous system that receives, integrates, and transmits nerve impulses is the neuron.