SYSTEM

CIRCULATORY

Major role:
to transport nutrients, gases (such as oxygen and CO2), hormones and wastes through the body.

Major organs:
heart, blood, blood vessels.

DIGESTIVE

Major role:
to breakdown and absorb nutrients that are necessary for growth and maintenance.

Major organs:
mouth, esophagus, stomach, small and large intestines, rectum, anus, liver, pancreas.

ENDOCRINE

Major role:
to relay chemical messages through the body.
In conjunction with the nervous system, these chemical messages help control physiological processes such as nutrient absorption, growth, etc.

Major organs:
many glands exist in the body that secrete endocrine hormones.
Among these are the hypothalamus, pituitary, thyroid, pancreas and adrenal glands.

LYMPHATIC/IMMUNE

Major role:
the main role of the immune system is to destroy and remove invading microbes and viruses from the body. The lymphatic system also removes fat and excess fluids from the blood.

Major organs:
lymph, lymph nodes and vessels, white blood cells, T- and B- cells.

NERVOUS

Major role:
to relay electrical signals through the body. It diverts behaviour and movement and, along with the endocryne system, control physiological processes such as digestion, circulation, etc.

Major organs:
brain, spinal cord and peripheral nerves.

REPRODUCTIVE

Major role:
to manufacture cells that allow reproduction. In the male, sperm are created to inseminate egg cells produced in the female.

Major organs:

• Female: ovaries, oviducts, uterus, vagina and mammary glands.
• Male: testicles, seminal vesicles and penis.

RESPIRATORY

Major role:

to provide gas exchange between the blood and the environment. Oxygen is absorbed from the atmosphere into the body and carbon dioxide is expelled.

Major organs:

• nose, trachea, nasopharynx, larynx, the lungs.

SKELETAL

• Major role:

to provide support for the body to protect delicate internal organs and to provide attachment sites for the organs.

• Major organs:

bones, cartilage, tendons and ligaments.