Body systems

Circulatory: 

Structure: Consists of the heart, arteries(carry blood away from the heart), veins(carry blood to the heart), capillaries(where nutrient and gas exchange occurs with tissue), and blood.

Function: Transports blood to every part of the body. The blood contains all the necessary gases,nutrients,and waste products which are all carried to the necessary parts of the body.

Digestive: 
Structure: Begins with the mouth, then esophagus, stomach, small intestine, large intestine, and ends with the rectum. The liver processes bile(digestive enzyme) and the gall bladder stores it. 
Function: Digests food and provides vital nutrients to the body, also helps to regulate the metabolism as well as eliminates waste.




Nervous: 
Structure: Broken down into 2 parts, the central nervous system(Brain and spinal cord, acts as the body's control center and coordinates body's activities)  and the peripheral nervous system(Carry messages to and from the central nervous system to the entire body)
Function: Controls all body activities




Endocrine: 
Structure: Consists of network of glands that include the pituitary, thyroid, thymus, pancreas, testes, ovaries, adrenal, and parathyroid glands.
Function: Contains glands that secrete hormones that are essential in the regulation of digestion, metabolism, and homeostasis




Reproductive:
Structure: Male reproductive system(Testis, tube that transports sperm called the vas deferens, urethra,and penis). The female reproductive system(ovaries, uterus, and vagina)
Function: Perpetuate the species through reproduction




Integumentary: 
Structure: Composed of two parts, the epidermis and the dermis. The epidermis is the outer thinner portion of the skin. The dermis is the inner thicker portion of the skin. It also contains the melanin(pigment in the skin), keratin(dead, waterproofing cells), and the hair. 
Function: Maintains equilibrium within the body, it regulates body temperature, and it serves as a protective layer to the body's underlying tissues.




Skeletal
Structure: Composed of two parts, the axial skeleton(Skull, vertebral column, ribs, and sternum) and the appendicular skeleton(bones of the arms and legs, shoulder, and pelvic bones).
Function: Provides framework for the body's tissue and protects the upper organs. Muscles are anchored to the bones to allow for movement. Bones also produce blood cells, and store vital minerals. 




Respiratory
Structure: Composed of two parts, the trachea(The passageway of air from the mouth or nasal cavity; it divides into 2 bronchi
Function: Provide the body with oxygen and to dispel carbon dioxide from the body.




Muscular
Structure: There are three types of muscles: smooth(found in internal organs and blood vessels), cardiac(found in the heart), and skeletal(attached to the bones).
Function: Smooth muscle allow for the contraction of organs and blood vessels. Cardiac muscle is responsible for the pumping of the heart, while the skeletal muscles allow movement. 




Excretory/Urinary
Structure: Kidneys(filter blood), uterus(tubes that lead from kidneys to urinary bladder), the urinary bladder(stores urine), and the urethra(tubes that lead from the urinary bladder to the outside of the body).
Function: Filter blood and remove major waste products such as ammonia and urea. Also regulates pH(acidity level) of the blood.




Immune/lymphatic
Structure: Lymph nodes and lymph vessels that are scattered throughout the body and help filter out antigens(Disease causing microorganisms). The tonsils, thymus gland, spleen, and bone marrow are also involved in the immune system.
Function: Protect the body from infections and antigens.