Which term is used for the chemical messengers in the nervous system, including GABA and acetylcholine?

Which term is used for the chemical messengers in the nervous system, including GABA and acetylcholine?

• A. Hormones
• B. Neurotransmitters
• C. Enzymes
• D. Receptors

Answer: (B)

Chemical messengers in the nervous system, such as GABA and acetylcholine, are called neurotransmitters. They’re released from the end of a neuron into the synapse and travel a very short distance to bind to receptors on the next cell, triggering a rapid and localized response. This quick signaling is essential for things like reflexes, muscle movement, and processing sensations. Hormones, by comparison, travel through the bloodstream to affect distant targets, so they’re endocrine messengers rather than the local communicators at synapses. Enzymes are not signaling molecules; they’re catalysts that speed up chemical reactions. Receptors, while crucial to signaling, are the proteins that receive the message, not the messengers themselves. Understanding this distinction helps you see why neurotransmitters are the correct term for these nervous system messengers. GABA typically helps reduce neuronal activity, while acetylcholine is key for activating muscles and many autonomic functions.

Chemical messengers in the nervous system, such as GABA and acetylcholine, are called neurotransmitters. They’re released from the end of a neuron into the synapse and travel a very short distance to bind to receptors on the next cell, triggering a rapid and localized response. This quick signaling is essential for things like reflexes, muscle movement, and processing sensations.

Hormones, by comparison, travel through the bloodstream to affect distant targets, so they’re endocrine messengers rather than the local communicators at synapses. Enzymes are not signaling molecules; they’re catalysts that speed up chemical reactions. Receptors, while crucial to signaling, are the proteins that receive the message, not the messengers themselves. Understanding this distinction helps you see why neurotransmitters are the correct term for these nervous system messengers. GABA typically helps reduce neuronal activity, while acetylcholine is key for activating muscles and many autonomic functions.