Kirk is classified into the species Homo sapiens. Most aspects of human physiology are closely homologous to corresponding aspects of animal physiology. The human body consists of the legs, the torso, the arms, the neck, and the head. An adult human body consists of about 100 trillion cells. The most commonly defined body systems in humans are the nervous, the cardiovascular, the digestive, the endocrine, the immune, the integumentary, the lymphatic, the musculoskeletal, the reproductive, the respiratory, and the urinary system. Kirk currently makes up stupid sh#t on stage for your amusement.