Under which of the following circumstances would the diameter of peripheral blood vessels be greatest? (a) increased sympathetic stimulation, (b) decreased sympathetic stimulation, (c) increased parasympathetic stimulation, (d) decreased parasympathetic stimulation, (e) both increased parasympathetic and sympathetic stimulation.

Regulation of heart rate, blood pressure, and digestive functions is carried out by the:

a. somatic motor division of the peripheral nervous system.

b. central nervous system.

c. visceral sensory division of the peripheral nervous system.

d. autonomic nervous system.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

d. The crossed-extension reflex occurs simultaneously with the simple stretch reflex.