Most _______ are secreted into the extracellular fluid from endocrine glands or tissues.
A) neurotransmitters
B) neuropeptides
C) modulators
D) hormones
E) pheromones

Question

Quizplus · Accepted Answer

Hormones are chemical messengers that are secreted by endocrine glands or tissues into the extracellular fluid and transported through the bloodstream to target cells or organs in distant parts of the body. Neurotransmitters are chemical messengers that are released into the synaptic cleft between neurons, while neuropeptides and modulators are also types of signaling molecules, but they are not primarily secreted by endocrine glands. Pheromones are chemicals that are released by one organism to affect the behavior or physiology of another organism of the same species, but they are not necessarily secreted by endocrine glands.

Most _______ Are Secreted into the Extracellular Fluid from Endocrine