What is diaphragm? Md. Saifur Rahman The Diaphragm is a muscular sheet, which separates the thoracic cavity from the abdominal cavity.You may likeDo I need car insurance?What is car insurance?How could I get cheaper car insurance?What is auto insurance?Why Adulterant food is the barrier to sound health?What are the producers?What are food preservatives?What is food chain?What is tertiary consumer?