ATI RN
Questions About the Nervous System Questions
Question 1 of 5
The cervical plexus is formed by the spinal nerves from which spinal levels?
Correct Answer: A
Rationale: The cervical plexus arises from C1-C4, serving neck and diaphragm.
Question 2 of 5
Which of the following toxins blocks Sodium Channels?
Correct Answer: C
Rationale: Tetrodotoxin (from pufferfish) blocks voltage-gated Na+ channels, halting action potentials. Strychnine blocks glycine, neostigmine inhibits acetylcholinesterase, curare blocks nicotinic receptors.
Question 3 of 5
The cell body of all sensory neurons is located within the:
Correct Answer: B
Rationale: The dorsal root ganglion (DRG) houses the cell bodies of sensory neurons, adjacent to the spinal cord. The dorsal gray horn processes sensory signals, the spinal cord is a broader structure, and the brain is not the site for sensory neuron cell bodies.
Question 4 of 5
The ___ is the innermost meningeal layer, clings tightly to the surface of the brain and spinal cord, following every fold.
Correct Answer: B
Rationale: The pia mater is the innermost meningeal layer, adhering closely to the brain and spinal cord. The arachnoid mater is the middle layer, dura mater the outermost, and tentorium cerebelli is a dura extension.
Question 5 of 5
The cell bodies of the preganglionic neurons of the sympathetic division are located within the:
Correct Answer: C
Rationale: Sympathetic preganglionic cell bodies are in the lateral horns of thoracic and lumbar (T1-L2) spinal cord gray matter, not cervical/sacral (parasympathetic) or white matter.