The first half of the medical curriculum is dedicated mostly to teaching the fundamentals of, or basic subjects relevant to, medicine, such as anatomy, histology, physiology, pharmacology, genetics, microbiology, ethics, and epidemiology. This instruction can be organized by discipline or by organ system. Teaching methods can include traditional lectures, problem-based learning, laboratory sessions, simulated patient sessions, and limited clinical experiences. The remainder of medical school is spent in clerkship. Clinical clerks participate in the day-to-day management of patients. They are supervised and taught during this clinical experience by residents and fully licensed staff physicians. Typical rotations include internal medicine, family medicine, psychiatry, surgery, emergency medicine, obstetrics and gynecology, and pediatrics. Elective rotations are often available so students can explore specialties of interest for residency training.