Muscle atrophy, or muscle wasting, results from loss of muscle tissue. Little or no physical exercise and a sedentary lifestyle are common causes of muscle atrophy, in this case called disuse atrophy.
PRIMARY KEY Constraints. A table typically has a column or combination of columns that contain values that uniquely identify each row in the table. This column, or columns, is called the primary key (PK) of the table and enforces the entity integrity of the table.
It is usually the primary key that is stored in other tables (in which â¦ case it is called a foreign key), to find the record in the specified table. For example, a client might be identified by a field ClientId, which uniquely identifies each client.