In human nervous tissue, which cells are considered support (neuroglial) cells rather than neurons?

Introduction / Context:
The nervous system contains two major types of cells: neurons, which transmit electrical impulses, and supporting cells known as neuroglia or glial cells. These supporting cells do not typically conduct impulses but are vital for maintaining the environment around neurons. This question asks you to identify which listed cell types are glial support cells rather than neurons.

Given Data / Assumptions:

• The options include astrocytes, oligodendrocytes, and ependymal cells.
• All of these are found in the central nervous system.
• The question focuses on support function rather than impulse conduction.

Concept / Approach:
Neuroglial cells perform functions such as providing structural support, forming myelin, maintaining the chemical environment, and lining fluid filled cavities. Astrocytes help regulate the extracellular environment and form part of the blood brain barrier. Oligodendrocytes form myelin sheaths around axons in the central nervous system. Ependymal cells line the ventricles and help circulate cerebrospinal fluid. Since all three listed cell types are forms of glia, the correct choice is the option that includes all of them.

Step-by-Step Solution:
Step 1: Evaluate option A. Astrocytes are star shaped glial cells that provide support and help maintain the environment for neurons, so they are support cells.Step 2: Evaluate option B. Oligodendrocytes are glial cells that form myelin around axons in the central nervous system, another classic support function.Step 3: Evaluate option C. Ependymal cells line the ventricles of the brain and the central canal of the spinal cord and are also considered supporting neuroglial cells.Step 4: Since all three individual cell types listed are neuroglia, the option that correctly summarizes this is option D, all of the above.

Verification / Alternative check:
An alternative check is to remember that the main named neuroglial cell types in the central nervous system are astrocytes, oligodendrocytes, microglia, and ependymal cells. When you see several of these listed together and the question asks about support cells, it is a strong clue that the combined option is correct.

Why Other Options Are Wrong:
Option A alone is incomplete because although astrocytes are support cells, the question does not ask for just one example but offers an option including all three. Option B alone is also incomplete because it ignores astrocytes and ependymal cells. Option C alone leaves out both astrocytes and oligodendrocytes. Therefore, only the option that includes all three correctly answers the question.

Common Pitfalls:
Students sometimes confuse neurons with glial cells or may incorrectly think that only one of the listed cell types is glial. Another pitfall is to overlook ependymal cells when recalling the main support cells of the nervous system. To avoid this, it is helpful to group astrocytes, oligodendrocytes, microglia, and ependymal cells together mentally as the major central nervous system glial cell types.

Final Answer:
All of the above.