The first heart sound ("lubb") is produced as the atrioventricular valves ________ and the semilunar valves ________.

A) open; close
B) close; open
C) open; open
D) close; close
E) The actions of the valves do not contribute to the heart sounds.


B) close; open

Anatomy & Physiology

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The most complex endocrine responses involve the

A) thyroid gland. B) pancreas. C) adrenal glands. D) hypothalamus. E) thymus gland.

Anatomy & Physiology

Describe metabolic acidosis

A) Metabolic acidosis occurs when pH decreases due to an impaired ability to remove CO2 by the lungs. B) Metabolic acidosis occurs when pH increases due to faster CO2 elimination by the lungs than production. C) Metabolic acidosis occurs when pH decreases due increased numbers of fixed and metabolic acids, from bicarbonate loss, or from depletion of bicarbonate reserve when hydrogen ions are not adequately excreted by the kidneys. D) Metabolic acidosis occurs when pH increases due to the removal of hydrogen ions when bicarbonate ion concentrations are elevated. E) Metabolic acidosis occurs when pH increases due to an impaired ability to remove CO2 by the lungs.

Anatomy & Physiology

________ is a trace mineral that is a component of hemoglobin, myoglobin, and cytochromes.

A) Magnesium B) Calcium C) Zinc D) Copper E) Iron

Anatomy & Physiology

How many single bonds can a carbon atom form if it is double-bonded to an oxygen atom?

A. 1 B. 2 C. 3 D. 4

Anatomy & Physiology