Large doses of certain stimulants can lead to dangerous increases in heart rates. Such a stimulant is a
A. positive chronotropic agent.
B. negative chronotropic agent.
C. positive inotropic agent.
D. negative inotropic agent.
A
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Which of the following are true regarding nails? Select all that apply.
_____ They are derived from the stratum corneum. _____ The growth zone is called the nail plate. _____ Nails are hard due to keratin. _____ The eponychium is also called the cuticle.
Which statement about the rate of diffusion through a lipid bilayer membrane is incorrect?
a. Smaller substances diffuse faster than larger substances. b. Lipid-soluble items diffuse faster than water-soluble items. c. Items diffuse through narrow membranes faster than through thick membranes. d. The presence of microvilli decreases the rate of diffusion. e. A greater concentration gradient causes faster diffusion.
GnRH
a. stimulates both FSH and LH secretion. b. is inhibited by testosterone. c. has low-level activity during the prepubertal period. d. both stimulates both FSH and LH secretion and is inhibited by testosterone. e. all of these answers.
Answer the following questions true (T) or false (F)
1. Arteries in the systemic circuit carry oxygenated blood while arteries in the pulmonary circuit transport deoxygenated blood. 2. Veins regulate blood pressure and control blood flow to organs. 3. Vessels with a smaller radius will have an increased resistance to blood flow.