Explain the role of pacemaker cells in cardiac tissue
What will be an ideal response
Pacemaker cells do not maintain a stable resting membrane potential. Instead, they have an unstable resting potential that continuously depolarizes, drifting toward threshold for firing. These spontaneously changing membrane potentials, called pacemaker potentials, initiate the action potentials that trigger the heart's rhythmic contractions.
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The minimum volume of air remaining in the lungs after a maximal expiration is called the
a. inspiratory reserve volume. b. inspiratory capacity. c. tidal volume. d. residual volume. e. expiratory reserve volume.
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A. interleukin-1 B. FAS ligands C. clones D. adjuvants
To determine that a type of epithelium is squamous, which of the following is most important?
A. the number of cell layers B. the shape of most of the epithelial cells C. the shape of the most superficial epithelial cells D. the shape of the basal epithelial cells E. the shape of the basement membrane