The human body is made up of multiple systems that work together to form life. Body systems are an organized

group of tissue that forms a particular function. These functions work with other systems in the body.

Some of the main systems of the body are:

Digestive System, Circulatory System, Nervous System,

Respiratory System, Muscular System, Urinary System,

Reproductive System, Lymphatic System,

Integumentary System Endocrine System

Digestive SystemDigestion is the system responsible for breakdown of

biomolecules. Biomolecules such as carbohydrates (sugars), proteins and lipids (fats) are absorbed in the

small intestine and delivered to the blood. The digestive system is a long path that starts from the mouth and ends

What is a Body System???

at the anus. Food travels down the esophagus to the stomach, where gastric juices begin the process of

breakdown. The food is sent to the small intestine, where pancreatic enzymes break down food into smaller

components for absorption. Finally, waste products are sent to the colon and excreted through the anus.

Circulatory SystemThe circulatory system is responsible for delivery of

oxygen and nutrients to the tissue in the organs. All cells in the body require oxygen for cellular reactions. This

oxygen, along with the biomolecules from the foods we

eat, are used to produce energy. The heart is also a part of this system. The heart is responsible for retrieving deoxygenated blood, pumping it to the lungs and then sending it through the arteries throughout the body.

Nervous SystemThe nervous system is the "control switch" of the body. The nervous system is made up of the brain, spinal cord

and the peripheral nerves that span to locations throughout the body. The nervous system retrieves

environmental input such as heat, touch, sound, and sight and sends it to the brain. The brain processes the input

and sends output back to the body using efferent nerves. These nerves are what control reactions such as walking,

talking and waving arms.

Respiratory SystemThe respiratory system is the part of the body that

processes gas exchange. When the body inhales, the air fills the lungs. The alveoli in the lungs are small balloons

that fill with air. These balloons are surrounded by

capillaries of deoxygenated blood pumped by the heart. The alveoli gives the blood the oxygen from inhaling and

then receives the carbon dioxide, which is a waste product of metabolism. When the body exhales, the carbon dioxide

is sent back out of the mouth, and the process is repeated.

Muscular SystemThe muscular system is the muscles throughout the body

that control movement. Most people initially label the muscular system as the muscles we know on our arms,

legs and stomach. These muscles are called skeletal

muscles. However, there are two other major groups of muscles. Smooth muscle is found in places like the

esophagus, where food is pushed from the mouth to the stomach. Smooth muscle is also located in the intestines.

The other type of muscle is cardiac muscle. Cardiac muscle is found in the heart.

Skeletal SystemThe adult human skeletal system consists of 206 bones, as well as a network of tendons, ligaments and cartilage that

connects them. The skeletal system performs vital functions — support, movement, protection, blood cell

production, calcium storage and endocrine regulation — that enable us to survive.

Urinary systemThe urinary system, also known as the renal system,

produces, stores and eliminates urine, the fluid waste excreted by the kidneys. The kidneys make urine by

filtering wastes and extra water from blood. Urine travels

from the kidneys through two thin tubes called ureters and fills the bladder. When the bladder is full, a person

urinates through the urethra to eliminate the waste.

Reproductive SystemThe reproductive system is a collection of internal and

external organs — in both males and females — that work together for the purpose of procreating. Due to its vital role in the survival of the species, many scientists argue

that the reproductive system is among the most important systems in the entire body.

Lymphatic SystemThe lymphatic system is a network of tissues and organs

that help rid the body of toxins, waste and other unwanted materials. The primary function of the

lymphatic system is to transport lymph, a fluid containing infection-fighting white blood cells, throughout the body.

The lymphatic system primarily consists of lymphatic vessels, which are similar to the circulatory system's veins and capillaries. The vessels are connected to lymph nodes, where the lymph is filtered. The tonsils, adenoids, spleen

and thymus are all part of the lymphatic system.

Integumentary SystemThe integumentary system is the organ system that

protects the body from various kinds of damage, such as loss of water or abrasion from outside. The system

comprises the skin and its appendages (including hair, scales, feathers, hooves, andnails). The integumentary system has a variety of functions; it may serve to waterproof, cushion, and

protect the deeper tissues, excrete wastes, and regulate temperature, and is the attachment site

for sensory receptors to detect pain, sensation, pressure, and temperature. In most terrestrial vertebrates with significant exposure to sunlight, the integumentary

system also provides for vitamin D synthesis.

Endocrine SystemThe endocrine system refers to the collection of glands of

an organism that secrete hormones  directly into the circulatory system to be carried towards distant target

organs. The major endocrine glands include the pineal gland, pituitary gland, pancreas, ovaries,testes, thyroid

gland, parathyroid gland, salivary gland, sweat glands, mammary glands,hypothalamus, gastrointestinal tract and adrenal glands. Special features of endocrine

glands are, in general, their ductless nature, their vascularity, and commonly the presence of intracellular

vacuoles or granules that store their hormones.