Question

what contribute to acid base balance

Answer 1

There are 3 main buffer systems in body which contribute to acid base balance are:-

CARBONIC ACID BICARBONATE BUFFER

Cellular respiration produces carbon dioxide as a waste product. This is immediately converted to bicarbonate ion in the blood. On reaching the lungs it is again converted to and released as carbon dioxide.

While in the blood , it neutralises acids released due to other metabolic processes. In the stomach and deudenum it also neutralises gastric acids and stabilises the intra cellular pH of epithelial cells by the secretions of bicarbonate ions into the gastric mucosa.

PHOSPHATE BUFFER SYSTEM

Phosphate buffer system operates in the internal fluids of all cells. It consists of dihydrogen phosphate ions as the hydrogen ion donor ( acid ) and hydrogen phosphate ion as the ion acceptor ( base ) . If additional hydroxide ions enter the cellular fluid, they are neutralised by the dihydrogen phosphate ion. If extra hydrogen ions enter the cellular fluid then they are neutralised by the hydrogen phosphate ion.

PROTEIN BUFFER SYSTEM

Protein buffer system helps to maintain acidity in and around the cells. Haemoglobin makes an excellent buffer by binding to small amounts of acids in the blood, before they can alter the pH of the blood. Other proteins containing amino acid histidine are also good at buffering.

The main purpose of all these buffers is to maintain proper pH within the body system so that all biochemical process can take place.

The buffer systems in the human body are extremely efficient, and different systems work at different rates. It takes only seconds for the chemical buffers in the blood to make adjustments to pH. The respiratory tract can adjust the blood pH upward in minutes by exhaling CO2 from the body. The renal system can also adjust blood pH through the excretion of hydrogen ions (H+) and the conservation of bicarbonate, but this process takes hours to days to have an effect.

The buffer systems functioning in blood plasma include plasma proteins, phosphate, and bicarbonate and carbonic acid buffers. The kidneys help control acid-base balance by excreting hydrogen ions and generating bicarbonate that helps maintain blood plasma pH within a normal range. Protein buffer systems work predominantly inside cells.

Physiologic range of the pH is 7,36-7,44.

Systems responsible for maintenance of the acid-base balance:-

1) Chemical buffering systems

Buffers react immediately – acute regulation. Capacity of buffers is not indefinite that is why chemical buffers act only in the short-term. Chemical buffering systems deal with pH deviations in common metabolism.

2) Respiratory system

Respiration reacts in 1-3 minutes. Respiratory system regulates carbon dioxide. Respiration is able to change pCO2 by its elimination or retention. Respiratory centre is in brainstem.

3) Kidneys

Kidneys react in hours-days. Their role in acid-base balance is very complex.

4) Liver

Liver is pivotal organ of the energetic metabolism it also have important influence on the acid-base balance. Liver is the most important tissue where ammonium is detoxified in both (1) urea cycle, and (2) glutamine synthesis. Which one of these fates of ammonium