A) weighs over 3 lbs. B) contains about 100 billion interneurons. C) is organized into 3 regions. D) contains many neuroglia; over half of it's volume. E) includes all of these characteristics. A) weighs over 3 lbs. B) contains about 100 billion interneurons. C) is organized into 3 regions. D) contains many neuroglia; over half of it's volume. E) includes all of these characteristics.

A) communicates with other cells via electrical signaling only. B) communicates with other cells via chemical signaling only. C) communicates with other cells via a combination of electrical and chemical signaling. D) is not involved in direct communication with other cells. E) does none of these. A) communicates with other cells via electrical signaling only. B) communicates with other cells via chemical signaling only. C) communicates with other cells via a combination of electrical and chemical signaling. D) is not involved in direct communication with other cells. E) does none of these.

A) include alcohol and barbiturates. B) slow motor response. C) enhance acetylcholine release. D) do all of these. E) include alcohol and barbiturates and slow motor response only. A) include alcohol and barbiturates. B) slow motor response. C) enhance acetylcholine release. D) do all of these. E) include alcohol and barbiturates and slow motor response only.

A) are highly addictive. B) distort sensory perception. C) include barbiturates. D) increase epinephrine secretion. E) do all of these. A) are highly addictive. B) distort sensory perception. C) include barbiturates. D) increase epinephrine secretion. E) do all of these.