There are eleven systems in the human body. Here is the list, including a brief description of each:
Skeletal - consists of the bones of the human body. We have a total of 206 bones that make up our skeletal structure.
Muscular - consists of all the muscles of the human body, like biceps, quadrilaterals, lateral obliques etc. We have an incredible amount of muscle tissue in our bodies, making up about 30-40% of our mass. "The number of muscles in the human body varies from about 656 to 850, depending on which expert you consult" (eNotes).
Nervous - the nervous system controls all of our actions, voluntary and involuntary. It consists of your brain, spinal cord, and the nerves that extend from it. Whether you're thinking of a solution to a problem or act on a reflex, your nervous system is behind every action.
Respiratory - the respiratory system controls your respiration, or breathing. It consists of your lungs and airway, or trachea.
Endocrine - the endocrine system manages the hormones in your body. Endocrine glands situated throughout your body, for instance the thyroid (located in your neck) or the pituitary gland (found in your brain), secrete hormones like testosterone and estrogen. These hormones can control anything from your metabolism to sleep habits and reproductive function.
Cardiovascular - this system circulates blood around your body via your heart, arteries, and veins. The process carries oxygen to your extremities and organs.
Digestive - the digestive system processes everything you eat. From the mechanical digestion of chewing and swallowing to the chemical digestion involving the breakdown of food with the aid of acid found in your stomach, everything food-related is controlled by the digestive system.
Excretory - this system excretes waste from your body. It includes your liver, kidneys and urinary system, large intestine and skin (sweating is a process of the excretory system).
Immune - your immune system keeps you healthy by fighting off disease and infection. It relies on cells throughout your body rather than any single organ. White blood cells (leukocytes) are one of the most important kinds of cells in fighting off foreign pathogens.
Integumentary - the integumentary system is sort of like a shell that protects you from external damage. The main organ of the integumentary system is our skin. It also consists of hair, nails, and exocrine glands (the glands via which we sweat, salivate, and lactate).
Reproductive - the reproductive system consists of the sex organs that allow us to reproduce and have children. These sex organs include both our external genitals as well as the organs that allow for sperm and egg production and storage, and in females the uterus, where a fertilized egg develops into a fetus.
The innerbody.com link below has a great graphic that will show you visually all of the organs involved in each system.