Author Question: After the effector cell has been stimulated by acetylcholine (ACh), what enzyme stops this ... (Read 83 times)

jparksx · **on:** Jul 23, 2018

After the effector cell has been stimulated by acetylcholine (ACh), what enzyme stops this stimulation and allows the effector membrane to repolarize?

A) Decarboxylase
B) Norepinephrine
C) Acetylcholinesteras e
D) Catecholamine

Question 2

The nurse is caring for a patient with hepatitis B. The patient is taking adefovir (Hepsera). Which medication would the nurse question if it were ordered?

A) Cimetidine (Tagament)
B) Diltiazem (Cardizem)
C) Diphenhydramine (Benadryl)
D) Telbivudine (Tyzeka)

Meganchabluk · **Reply #1 on:** Jul 23, 2018

Answer to Question 1

C
Feedback:
After the effector cell has been stimulated by ACh, stimulation of the receptor site must be terminated and destruction of any ACh must occur. The destruction of ACh is carried out by the enzyme acetylcholinesteras e. This enzyme reacts with the ACh to form a chemically inactive compound. The breakdown of the released ACh is accomplished in 1/1,000 second, and the receptor is vacated, allowing the effector membrane to repolarize and be ready for the next stimulation. Dopa decarboxylase is an enzyme that converts dopa to dopamine. Norepinephrine is a catecholamine as are dopamine, serotonin, and epinephrine.

Answer to Question 2

D
Feedback:
Telbivudine is an antihepatitis B agent, and when given with adefovir (Hepsera) can result in severe hepatomegaly with steatosis, sometimes fatal. Cimetidine is a histamine-2 antagonist, diltiazem is a calcium channel blocker, and diphenhydramine is a first-generation antihistamine. These drugs are normally not considered nephrotoxic and could be used with adefovir.