Parasympathetic effects are localized and short-lived because
A) muscarinic receptors are deactivated by norepinephrine.
B) acetylcholine is inactivated at the synapse by acetylcholinesterase.
C) norepinephrine hyperpolarizes the postganglionic membrane.
D) norepinephrine is inactivated at the synapse by monoamine oxidase.
E) epinephrine blocks the muscarinic receptors.
B
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A parathyroid gland that is overresponsive to blood calcium levels will produce abnormally high amounts of calcitonin and cause bones to rapidly gain calcium.
Answer the following statement true (T) or false (F)
Your young child has a middle ear infection: otitis media. There is a build-up of fluid, bacteria, and white blood cells, or pus, inside of the middle ear chamber. Why has this affected the child's hearing?
A) The cochlear receptor cells cannot move. B) The bacterial infection has destroyed the otoliths. C) The round window cannot vibrate to dissipate pressure. D) The auditory ossicles cannot vibrate freely. E) The tympanum is destroyed.
Sweating is initiated in response to a rise in body temperature that occurs on exposure to a hot environment. Evaporation of the sweat cools the body. This is an example of
a. negative feedback. b. positive feedback. c. a feedforward mechanism. d. an intrinsic (local) control mechanism. e. autoregulation.
Which digestive secretion is correctly matched to its function?
A. Secretin - release of hydrochloric acid B. Cholecystokinin (CCK) - release of alkaline pancreatic juices and bile C. GIP - decreased release of bile D. Gastrin - release of alkaline secretions from the pancreas