Identify and describe the operation of the three major chemical buffers of the body.
What will be an ideal response?
The bicarbonate buffer system (carbonic acid plus sodium bicarbonate) acts to tie up the hydrogen ions released by a strong acid, thus converting it to a weaker acid, which lowers the pH only slightly. For a strong base, the carbonic acid will be forced to donate more H+ to tie up the OH- released by the base, with the net result of replacement of a strong base by a weak one. The pH rise is very small. The phosphate buffer system, composed of the sodium salts of dihydrogen phosphate and monohydrogen phosphate, acts in a similar fashion to the bicarbonate system. NaH2PO4 acts as a weak acid; Na2HPO4 acts as a weak base. Hydrogen ions released by strong acids are tied up in weak acids; strong bases are converted to weak bases. Amino acids of the protein buffer system release H+ when the pH begins to rise by dissociating carboxyl groups, or bind hydrogen ions with amine groups to form NH3+ when the pH falls.
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Which has the greater concentration of hydrogen ions, a substance with a pH of 5 or a substance with a pH of 4?
A) A pH of 4 is greater. B) A pH of 5 is greater. C) They are both equal; 4 and 5 are relative values. D) pH 9, if you mixed the solutions. E) There is not enough information to determine the answer.
Ruffini corpuscles are associated with __________ and detect __________
A) The skin surface; light touch and pressure B) Hair follicles; changes in movement on the skin surface C) Connective tissue of skin; skin stretch D) Deep subcutaneous tissue, muscle, joints; deep pressure and touch Fill in the blank with the correct answer.
__________ __________ syndrome is a condition caused by prolonged repetitive motions of the wrist and fingers.
Fill in the blank(s) with the appropriate word(s).
The curvature of the lens must be adjusted to enable the eye to focus both near and far sources on the retina
Indicate whether the statement is true or false