INTERNAL HUMAN ANATOMY

CARDIOVASCULAR SYSTEM
The cardio vascular system, or the circulatory system, has one main job: to pump blood throughout the body. The system's major organ is the heart, which pumps blood through the arteries into all parts of the body. Blood contains oxygen, hormones and nutrients that cells need to grow, work, and repair themselves. Cells take in these products and give off carbon dioxide and other waste materials, which the blood then carries through the veins to the organs that remove the waster from the body.

MUSCULAR SYSTEM
Different types of muscles are located throughout the body. Skeletal muscles are attached to the body's bones and move them by contracting and releasing. Smooth muscles line the digestive system and help move food and water through it cardiac muscles are found in the heart. They pump blood through the heart to the lungs and the rest of the body.

SKELETAL SYSTEM
The skeletal system is made up of bones, joints and cartilage, which is flexible tissue that forms body parts like the nose and ears. Cartilage also helps bones and joints work together smoothly. The body's bones have four main functions. First, they support the body and work with muscles to help it move in different ways, as well as to carry weight. Second, they protect the other organs in the body from injury. For example, your skull protects your brain, and your ribs protect many of your soft internal organs. Third, bones store important minerals such as calcium and phosphorus, releasing them into the bloodstream when the body's other organs needs them. Finally, bones produce blood cells.

IMMUNE SYSTEM
Diseases in the form of bacteria, viruses, toxins and microbes can attack your body. Your immune system fights off disease and helps to keep you health in many ways. Lymph, a liquid produced by lymph nodes in various parts of the body, is carried in the bloodstream to the cells to clean them of harmful bacteria and waste products. The center of bones called bone marrow is where red and white blood cells are created. White blood cells are important because they produce antibodies, which kill toxins, bacteria and viruses. The thymus, which is located in the chest, produces special cells that fight disease. The spleen filters out old red blood cells and other foreign bodies, such as bacteria. The adenoids (behind the nose) and tonsils (in the throat) also trap and kill bacteria and viruses.

ENDOCRINE SYSTEM
The organs of this system are called glands. They produce hormones, which are chemicals that travels through your bloodstream and tell your organs what to do. For this reason, hormones are often referred to as the body's messengers. The endocrine system works to regulate mood, growth, body development, sleep, blood pressure and metabolism, which is the process by which the body changes food into energy.