Medical Assistants perform routine administrative and clinical tasks in the offices and clinics of physicians, podiatrists, chiropractors and optometrists. In small practices, they are “generalists,” who handle both administrative and clinical duties and report directly to an office manager, physician, or other health practitioner. Those in large practices tend to specialize in a particular area under the supervision of department administrators. Clinical duties vary according to state law, and may include taking medical histories and recording vital signs, explaining treatment procedures to patients, preparing patients for examination, and assisting the physician during the examination. Medical Assistants collect and prepare laboratory specimens or perform basic laboratory tests on the premises, dispose of contaminated supplies, and sterilize medical instruments.