the system of blood, blood vessels, lymphatics, and heart that functions to circulate the blood, providing nutrients and removing waste from cells

the system concerned with the ingestion, digestion, and absorption of food and the discharge of residual wastes; consisting of the digestive tract and accessory glands (such as the salivary glands and the pancreas) that secrete digestive enzymes

the glands and parts of glands that produce endocrine secretions, help to integrate and control bodily metabolic activity, and include the pituitary, thyroid, parathyroids, adrenals, islets of Langerhans, ovaries, and testes

the system that protects the body from foreign substances, cells, and tissues by producing the immune response and that includes especially the thymus, spleen, lymph nodes, special deposits of lymphoid tissue (as in the gastrointestinal tract and bone marrow), macrophages, lymphocytes including the B cells and T cells, and antibodies

specific variation in the characteristics of organisms received from a parent or ancestor by genetic transmission
 

the external layer or covering (as in skin, hair, scales, feathers, or cuticle) of an organism or one of its parts and that functions as a barrier to protect the body and its organs

the system of muscles in the body, which functions to allow movement of body parts for locomotion and other actions

the system that in vertebrates is made up of the brain and spinal cord, nerves, ganglia, and parts of the receptor organs and that receives and interprets stimuli and transmits impulses to the effector organs

an individual form of life, such as a plant, animal, bacterium, protist, or fungus; a body made up of organs, organelles, or other parts that work together to carry on the various processes of life

the system of organs and parts which function in reproduction (to produce offspring); in the male consists of the testes, penis, seminal vesicles, prostate, and urethra and in the female consists of the ovaries, fallopian tubes, uterus, vagina, and vulva

a system of organs functioning in respiration for gas exchange; in humans, the respiratory system consists of the nose, nasal passages, pharynx, larynx, trachea, bronchi, and lungs

a usually rigid supportive or protective structure or framework of an organism; in humans, the skeletal system consists of bones, cartilage, and ligaments

regularly interacting or interdependent group of items forming a unified whole

the organs of the urinary tract comprising the kidneys, ureters, urinary bladder, and urethra that function to remove waste from the body