Bone is a hard tissue of the body. It is made up of mineral in the form of calcium phosphate and protein in the form of collagen. When acid is present this calcium can be removed from the bone making it weaker. Normally the bone in the body is broken down and replaced throughout our lifetime. Remodeling or bone turnover is the process of resorption followed by replacement of bone with little change in shape and occurs throughout a person's life.
(Wikepedia)Acid acts on the bone in a closed environment to remove calcium and remove the bone before it is replaced by new bone.The cells involved in resorbing bone are osteoclasts and they secrete acids to demineralise the bone. Bone formation takes place by different cells called osteoblasts. These cells require an alkaline environment to form bone. In the laboratory placing bone in acid causes the entire bone to be broken down. Acid affects bones causing loss of calcium from the bones.
This is called demineralisation. In an experiment on whether a decalcified bone resorbs calcium. Yes it can resorb calcium. However very little calcium is resorbed.In an experiment it was seen that weakened bones didn’t absorb a greater amount then unweakened bones.
(Sandeep, J) Indeed even if bones are left for a long time in a strong acid they will seem to be softer when they are removed. Even the collagen in the bone which is a protein is eventually affected and denatured. This is if the bone is exposed to acid over a long period as when kept in the laboratory in a Petri dish. Increasing the concentration of the acid will increase the demineralisation of bone.However in the body it is the cells that physically work to maintain the bones.
Indeed these cells are involved with the overall maintenance of calcium in the body and respond to various hormones as well. Calcium is absorbed by the intestine and excreted by the kidney . When calcium levels are low in the body more calcium is absorbed from the intestine and less is excreted by the kidney. There are many diseases where the bones loose calcium.
Osteoporosis occurs when calcium is being lost from the bones more then is being replaced. Osteoporosis literally means ‘porous bones’.Our bones are made up of a thick outer shell and a strong inner honeycomb mesh of tiny struts of bone. (National Osteoporosis society 2007) Metabolic acidosis is a condition where the body looses more calcium and so the bones become weak. An acidic environment prevents calcium from being deposited so it is important that the environment changes to an alkaline one if calcium is to be redeposited on bone. Acidosis increases activity of the bone resorbing cells, the osteoclasts, and decreases activity of the bone forming cells, the osteoblasts.
(Bushinsky DA, Frick KK, 2000)
