With reference to acid-base balance explore the role of the respiratory system in maintaining blood pH?
‘We live and die at the cellular level’ (Reid, 2011). Homeostasis is crucial for normal cellular function. Acid-base homeostasis is the part of human homeostasis and refers to the balance between the production and elimination of H+ hydrogen ions (pH) within the body fluids (William, Simpkins, 2001, p.236). Metabolic reactions within the cells often produce a huge excess of H+. Lack of any mechanism for its excretion would lead H+ levels in body fluids rise quickly to the lethal levels (Tortora, Grabowski 2006, p.1001); therefore the homeostasis of the right H+ levels is crucial for our survival. In a healthy person several systems work interdependently on maintaining blood’s pH (Sheldon, 2001, p.23): buffer, renal and respiratory systems. In this essay I will concentrate on the pH of the blood in relation to the acid-base balance and the role that respiratory system has in maintaining it.
Blood pH is a measure of its acidity or alkalinity. A pH of 7.4 is considered neutral in the systemic arterial blood within its narrow range of around 7.35 and 7.45. When the pH is greater than 7.45 the blood is considered to be alkalotic and when the pH is lower than 7.35 then the blood is considered acidotic (Sheldon, 2001, p.23).
Fig. 1: Diagram of blood pH scale:
The acidity or alkalinity of blood is a result of H+ concentration within it, and this on the other hand results from the carbon dioxide concentration in the blood. Carbon dioxide is a toxic waste product generated in the oxidation of fats, carbohydrates and proteins within the cells. The gas itself is not an acid, but it reacts with water to form carbonic acid which then dissociates to form a hydrogen ion and a bicarbonate ion: CO2+H2O↔ H2CO3↔H++ HCO3-
The respiratory system helps to control the acidity of...