19 what are the three major buffer systems in body

This preview shows page 3 - 4 out of 5 pages.

are the greatest threat because of the large amounts generated by normal cellular processes. 19. What are the three major buffer systems in body fluids? flow does each system work? Phosphate buffer system : This buffer system consists of H2P0.1, a weak acid that, in solution, reversibly dissociates into a hydrogen ion and HPO42-. The phosphate buffer system plays a relatively small role in regulating the pit of the ECF because the ECF contains far higher concentrations of bicarbonate ions than phosphate ions; however, it is important in buffering the pH of the ICF . Protein buffer systems : These depend on the ability of amino acids to respond to changes in pH by accepting or releasing hydrogen ions. If the pH rises, the carboxyl group of the amino acid dissociates to release a hydrogen ion; if the pH drops, the amino group accepts an additional hydrogen ion to form an amino ion (NH 3 + ) and the carboxylate ion can accept a hydrogen ion to form a carboxyl group. Plasma proteins contribute to the buffering capabilities of the blood; inside cells, protein buffer systems stabilize the pH of the ECF by absorbing extracellular hydrogen ions or exchanging intracellular hydrogen ions for extracellular potassium. Carbonic Acid-bicarbonate System : Most carbon dioxide generated in tissues is converted to carbonic add, which dissociates into a hydrogen ion and a bicarbonate ion. Hydrogen ions released by dissociation of organic or fixed acids combine with bicarbonate ions, elevating the Pco 2 ; additional CO2 is lost at the lungs. 20. How do respiratory and renal mechanisms support the buffer systems? Respiratory and renal mechanisms support buffer systems by secreting or absorbing hydrogen ions, by controlling the excretion of acids and bases, and by generating additional buffers. 21. Differentiate between respiratory compensation and renal compensation. Respiratory compensation is a change in the respiratory rate that helps stabilize the pH of the ECF. Increasing or decreasing the rate of respiration alters pH by decreasing or increasing the pco2. When the Pco2 decreases, the PH increases; when the Pco2, increases, the PH decreases.
Image of page 3

Subscribe to view the full document.

Renal compensation is a change in the rates of hydrogen and bicarbonate ion secretion or reabsorption in response to changes in plasma PH. Tubular hydrogen ion secretion results in the
Image of page 4
You've reached the end of this preview.
  • Spring '17
  • ditmore
  • pH, ECF, Bicarbonate

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern