The Systems

Respiratory System:


Main function: 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.

Circulatory System:

Main function: it transports water, nutrients, hormones, gases (such as oxygen and CO2), and waste through the body.

Major organs: heart, blood, blood vessels.

Digestive System:

Main function: to break down and absorb nutrients that are necessary for growth and maintenance.

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

Skeletal System:

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

Major organs: bones, cartilage, tendons, ligaments.

Endocrine System:

Main function: 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.

Nervous System:

Main function: to relay electrical signals through the body. It directs behaviour and movement and with the endocrine system, control physiological processes such as digestion, circulation, etc.

Major organs: brain, spinal cord and peripheral nerves.

Limphatic System:

Main function: 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.