In her group, Melanie is always the one who breaks the tension with a funny story and provides a shoulder to cry on when things go wrong. She can be described as playing a(n) ____ role

Glutamate is an excitatory neurotransmitter that helps regulate a person's state of arousal and attention.

a. true b. false

Most people would say the one sense they fear losing most is vision. What physical aspect of the nervous system supports this opinion?

a) There are more neurons in the brain devoted to vision than other senses. b) The visual receptors use a greater variety of neurotransmitters than any other sense. c) The visual receptors have the most direct connections to the brain of all the sensory receptors. d) Visual receptors are located closer to brain areas responsible for vision than are receptors for any other sense.