paracrines
a. are long range chemical mediators that are specically secreted into the blood by endocrine glands and are carried to distant target organs
b. are hormones released into the blood specifically by neurosecretory neurons
c. are hormones released specifically from the parathyroid glands
d. are local chemical mediators whose effect is exerted only on neighboring cells in the immediate environment of thier site of secretion
e. are very short range chemical mediators released by neurons in response to action potentials
e.
