The action potential in a cardiac contractile cell causes
A) activation of sodium-potassium ATPase.
B) opening of ryanodine receptor calcium channels.
C) opening of L-type calcium channels.
D) opening of HCN channels.
E) activation of NCX transporters.
C) opening of L-type calcium channels.
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Secondary bronchi are also termed ________ bronchi.
A) tertiary B) lobar C) segmental D) lobular E) None of the answers are correct.
At rest, the tropomyosin molecule is held in place by
A) Actin molecules. B) Myosin molecules. C) Troponin molecules. D) ATP molecules. E) Calcium ions.
Which type of cell has abundant ribosomes?
A. Cardiac muscle cells (require large amounts of ATP) B. Fibroblast (makes protein fibers) C. Liver cells that detoxify hydrogen peroxide D. White blood cell, a phagocyte E. Red blood cell (transports oxygen)
Which of the following is NOT true of joint movements?
A. In the upper and lower limbs, the origin is typically proximal to the insertion. B. The more moveable end of a skeletal muscle is called its insertion. C. When a skeletal muscle contracts to move a joint, the insertion is pulled toward the origin. D. Most joints are flexed and abducted when the body is in anatomical position. E. All of these are true of joint movements.