Given that impulses from parasympathetic nerves decrease heart rate, and that the neurotransmitter for parasympathetic postganglionic fibers is acetylcholine (ACh), predict how the following chemicals might affect heart rate
A) Pilocarpine, a drug that simulates the action of ACh, will increase heart rate; and atropine, a drug that blocks the action of ACh, will decrease heart rate.
B) Pilocarpine, a drug that simulates the action of ACh, will decrease heart rate.
C) Atropine, a drug that blocks the action of ACh, will decrease heart rate.
D) Pilocarpine, a drug that simulates the action of ACh, will increase heart rate.
Answer: B
You might also like to view...
A term meaning toward the back of the body or body part is ___________________.
Fill in the blank(s) with the appropriate word(s).
During oxidative phosphorylation, hydrogen atoms are passed serially from a coenzyme down a chain of molecules called cytochromes.
Answer the following statement true (T) or false (F)
In Guillain-Barre syndrome, the immune system attacks and degrades the myelin sheath of PNS axons. Predict the effect this will have on nerve impulse and motor function.
A. Motor signals will not be sent from the brain down the efferent pathway because the brain cannot generate them. B. Lost insulation from myelin will cause neurons of the PNS to be hyper-excitable and muscular spasms will result. C. The brain will slowly degrade and various brain functions will be lost, including motor functions. D. Lost insulation from myelin will cause neurons of the PNS to lose saltatory conduction, resulting in poor muscle function.
Melanocytes and keratinocytes work together in protecting the skin from UV damage when keratinocytes ________
A) maintain the appropriate pH in order for the melanocyte to synthesize melanin granules B) maintain the appropriate temperature so the product of the melanocyte will not denature C) accumulate the melanin granules on their superficial portion, forming a UV-blocking pigment layer D) provide the melanocyte with nutrients necessary for melanin synthesis