Consciousness is the awareness of INTERNAL and EXTERNAL stimuli; often described as a continuum ranging from full awareness to deep sleep.
Explanation:
Internal stimuli include pain, hunger, thirst while external stimuli include light, sound.
Variation of consciousness is seen in different physical states ranging from full alertness to deep sleep. This is controlled by the biological clock, the circadian rhythm.
Axons are not maintained by microtubules. Microtubules are used in axons as railways to transport different molecules to the terminal branches of the axon or to the soma of the neuron. Axons are maintained by a special type of cells called Schwann cells.
