What does the suffix "-ology" mean and what medical specialties use it?

The suffix ology means the study of and is used to name medical specialties and scientific disciplines. Cardiology is the study of the heart, neurology is the study of the nervous system, dermatology is the study of the skin, oncology is the study of cancer, urology is the study of the urinary system, ophthalmology is the study of the eye, gastroenterology is the study of the digestive system, endocrinology is the study of hormones, hematology is the study of blood, and pulmonology is the study of the lungs. ---