This chemical is released from the adrenal gland and travels through the bloodstream. It fits into the receptors on almost every cell in the body. The chemical is a(n)

a. neurotransmitter.
b. neurohormone

One of the reasons that Viagra has become so widely accepted as a treatment for erectile dysfunction is that a. it is more effective than the other available treatments

b. it is less expensive than other medications, such as vasodilators. c. people are unaware of the other options. d. an oral medication is less awkward and intrusive than other treatments.

For a dying person, profound depression __________

A) impairs the immune response B) inhibits pain and suffering C) is associated with increased survival D) does not respond to treatment