The effectors of the body include

Correct Answer: C

Rationale: Effectors are tissues that respond to neural signals, such as glands (secreting hormones) and muscles. Cranial nerves and spinal cord are neural, and the brain is CNS.

Correct Answer: B

Rationale: Nissl bodies are rough endoplasmic reticulum in neurons, synthesizing proteins. Mitochondria produce energy, lysosomes degrade waste, and Golgi processes proteins.

Correct Answer: A

Rationale: The axon transmits action potentials; its destruction prevents signal propagation. Neurons have one axon, and dendrites receive stimuli, so only transmission is affected.

Correct Answer: C

Rationale: Larger diameter axons (Neuron A) have lower resistance, transmitting action potentials faster. Strength is all-or-none, not diameter-dependent.

Correct Answer: C

Rationale: Astrocytes help form and maintain the blood-brain barrier, supporting neurons by regulating blood-neuron interactions. Myelin is from oligodendrocytes, neurofibrils are structural, and synapses are junctions.