unmyelinated: The effector organs in the somatic reflex are closer to the spinal cord.
48. If a cell has alpha1 adrenergic receptors, it is sensitive to acetylcholine (ACh), norepinephrine (NE), muscarine, alpha adrenaline, and nicotine.
49. Muscarinic receptors bind acetylcholine, epinephrine, norepinephrine, monoamine oxidase (MAO), and acetylcholinesterase.
50. The binding of acetylcholine to a nicotinic receptor of muscle fiber will excite; norepinephrine will excite; monoamine oxidase will inhibit; acetylcholine will inhibit; acetylcholinesterase will excite.