Why do asthma sufferers often use inhalers that contain sympathomimetics to ease their symptoms?
A. Sympathomimetics suppress release of norepinephrine and epinephrine.
B. The drugs are antagonists that bind to adrenergic receptors in the bronchial tubes without stimulating them.
C. The drugs are agonists that stimulate adrenergic receptors in the bronchial tubes.
D. The sympathomimetics bind to muscarinic receptors and block them.
E. Sympathomimetics enhance the release of acetylcholine from preganglionic and postganglionic neurons.
C. The drugs are agonists that stimulate adrenergic receptors in the bronchial tubes.
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The receptor membranes of gustatory cells are ________
A) taste buds B) basal cells C) gustatory hairs D) fungiform papillae
During implantation, why doesn't the hyaluronidase erode the trophoblast as well as the endometrium?
A) The trophoblast secretes an enzyme that breaks down the hyaluronidase. B) The endometrium inactivates the enzyme before it can act on the trophoblast. C) The trophoblast is coated in anti-hyaluronidase. D) The outer layer of the trophoblast is syncytial, with no cell junctions for the enzyme to attack. E) None of the answers are correct.
The pulse pressure is the
a. difference between the systolic and diastolic pressure. b. average pressure throughout the cardiac cycle. c. maximum pressure exerted in the arteries. d. minimum pressure exerted in the arteries. e. change in pressure that can be felt in an artery due to shutting of the aortic valve.
What is the purpose of motor nerve varicosities as they relate to smooth muscle?
A. They prevent single-unit smooth muscle cells from pulling apart. B. They enable each cardiomyocyte to directly stimulate its neighbors. C. They link the thin filaments to the inside of the sarcolemma in smooth muscle. D. They reabsorb the decomposition products of acetylcholine after acetylcholinesterase breaks it down. E. They release neurotransmitter molecules onto smooth muscle cells.