In an intact heart, the functional pacemaker is the ____________________.
Purkinje fibers
sinoatrial node
atrioventricular node
bundle branches
Bundle of His
sinoatrial node
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Which of the following small intestine cells secrete lysozyme?
a) Goblet cells b) Absorptive cells c) Mucosa cells d) Paneth cells e) S cells
When the heart is in fibrillation,
A) the myocardial cells deplete their oxygen supply because they are contracting too fast, and the lactic acid produced damages the myocardial cells. B) effective pumping of the ventricles ceases because the myocardial cells fail to work as a team, and the brain cannot get adequate oxygen. C) there is no contraction of the myocardium. D) the myocardial cells are contracting together as they should; fibrillation indicates a normal sinus rhythm of 75 beats per minute. E) the myocardial cells may become damaged from contracting too fast.
In humans, the muscles responsible for moving the outer visible part of the ear, the pinna, are considered to be vestigial structures
Indicate whether the statement is true or false
The ejection of a mature egg from the ovary is called ____
a. ovulation b. gestation c. menstruation d. corpus luteum