When admitted to the emergency room, Sean was holding his right hand, which had a deep puncture hole in its palm. He explained that he had fallen on a nail while exploring a barn. Sean was given an antitetanus shot to prevent neural complications. Tetanus bacteria fester in deep, dark wounds, but how do their toxins travel in neural tissue?

Local anesthetics block voltage-gated Na⁺ channels. General anesthetics are thought to activate chemically gated Cl⁻ channels, thereby rendering the nervous system quiescent while surgery is performed. What specific process do anesthetics impair, and how does this interfere with nerve impulse transmission?

Rochelle developed multiple sclerosis when she was 27. After eight years she had lost a good portion of her ability to control her skeletal muscles. How did this happen?

The effects of neurotransmitter binding are very brief. Explain.

Describe the events that must occur to generate an AP. Relate the sequence of changes in permeability to changes in the ion channels, and explain why the AP is an all-or-none phenomenon.

What is the polarized membrane state? How is it maintained? (Note the relative roles of both passive and active mechanisms.)

Explain both the anatomical and functional divisions of the nervous system. Include the subdivisions of each.