Lecture 39 4/12/24 Flashcards
What is pH?
the negative log of H+ conc.
What is an acid?
substance that can donate H+
What is a base?
substance that can accept H+
What is a strong acid?
acid that gives up all H+ in solution
What is a weak acid?
acid that only releases some H+ when in solution
What is a buffer?
-chemical that helps minimize changes in pH in a solution
-typically occurs as a buffer pair, such as a weak acid and conjugate base
What are the main contributors to acid-base homeostasis?
-buffers
-lungs
-kidneys
What are the characteristics of how buffers work?
-work quickly to titrate excess H+
-more of a chemical reaction that a physiologic response
What is the main buffer in the body?
HCO3- (bicarb.)
What are the characteristics of carbonic anhydrase?
-produced by RBCs and renal tubular cells
-speeds up the Henderson-Hassalbalch equation in both directions
What is the Henderson-Hassalbalch equation?
CO2 + H2O <-> H2CO3 <-> HCO3- + H+
What are the characteristics of CO2?
-acts as a resp. acid
-delivered to the lungs, where it can be breathed out
What do central chemoreceptors respond to?
CO2 and pH
What do peripheral chemoreceptors respond to?
CO2, pH, and PaO2
What is the ventilatory response to CO2?
ventilation increases dramatically once PaCO2 reaches a threshold level
What are the characteristics of hypoventilation?
-retain CO2
-increased pCO2
-decreased blood pH