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Our Science Glossary glossary_r



Bone resorption is the process by which osteoclasts break down bone and release the minerals, resulting in a transfer of calcium from bone fluid to the blood. If bone resorption is greater than bone deposition then bone mass disorders such as osteoporosis can occur.

Restless leg syndrome

A neurological disorder, the symptoms of which are numbness, tingling and creeping sensations in the legs which create a powerful urge to move the legs to relieve these feelings and which results in restlessness and lack of sleep. It is caused by a deficiency in the dopaminergic system.


In biochemistry, a receptor is a protein on the cell membrane or within the cytoplasm or cell nucleus that binds to a specific molecule (a ligand), such as a neurotransmitter, hormone, or other substance, and initiates the cellular response to the ligand.

Rheumatoid arthritis

A chronic, inflammatory autoimmune disorder that causes the immune system to attack the joints. It is a disabling and painful inflammatory condition, which can lead to substantial loss of mobility due to pain and joint destruction. Rheumatoid arthritis is a systemic disease, often affecting extra-articular tissues throughout the body including the skin, blood vessels, heart, lungs, and muscles. About 60% of patients are unable to work ten years after the onset of their disease.


A chemical similar to DNA from which proteins are made. Unlike DNA, RNA can leave the nucleus of the cell.