In the 1920s, Otto Loewi discovered that
a. a frog heart would beat outside the animal.
b. the nerve to a frog’s heart released a chemical
that affected only that heart.
c. neuron endings release a neurotransmitter when
stimulated.
d. a saline solution caused an isolated frog heart
deprived of its own nerve supply to beat more
slowly.
e. ACh acts on skeletal muscle, smooth muscle, the
heart, some glands, and the brain.
Answer: c
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A zombie apocalypse wipes out almost the entire human species before the zombie threat is eliminated. Only a group of 100 people who were at a family reunion on an uninhabited island survived. They returned to the mainland completely unaware of what had happened to everyone. Answer the following question(s) regarding the few survivors who now begin to rebuild the human population.Which of the following processes is most likely to occur on this small population of humans?
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The pulmonary circulation
a. involves the hepatic portal vein. b. moves oxygen-rich blood to the kidneys. c. includes the coronary arteries. d. leads to, through, and from the lungs. e. leads to, through, and from the heart.
Carbohydrates have which one of the following characteristics?
A) They are composed of carbon, hydrogen, nitrogen, and oxygen. B) They release energy when their peptide bonds are broken. C) They are indigestible by most organisms. D) They contain carbon, hydrogen, and oxygen in a ratio of 1-2-1. E) They are able to store and transmit genetic information.
Graded motor unit recruitment is important to allow for coordinated movement to occur. According to Henneman's Size Principle, which motor units would be recruited first when voluntarily activated?
a. Type IIa b. Type IIb c. Type I d. All of the above