Endocrine System:
The study of endocrine hormones that carry signals throughout the body, helping it to respond as a whole. The major endocrine glands (pituitary, thyroid, adrenal, pancreas, parathyroid, and gonads) are a major focus, but nearly all organs release endocrine hormones. Immune System: The body's natural defense system is made up of white blood cells, the thymus, and the lymphatic systems. A complex series of receptors and molecules combine to protect the host from attack by pathogens. Molecules such as antibodies and cytokines are of great importance. Integumentary system: the skin, hair, nails, sweat glands, and sebaceous glands (which secrete an oily or waxy substance). Musculoskeletal system: the skeleton and muscles, tendons, ligaments and cartilage. It includes the bone marrow, where red blood cells are made and how bones store calcium and phosphate. Nervous system: the central nervous system (brain and spinal cord) and the peripheral nervous system. The study of the nervous system includes investigation of the senses, memory, emotions, movement.
