Speaking of oxygenating your blood, think about how that oxygen finds its way into your body. You may not consciously think about it every day, but breathing makes it all possible. The body’s trillions of cells need oxygen and must get rid of carbon monoxide, and this exchange of gases is accomplished by the respiratory system. External respiration is the repetitive, unconscious exchange of air between the lungs and the external environment . The nervous system is made up of the central nervous system (CNS), which includes the brain and spinal cord. The peripheral nervous system (PNS) is composed of cranial nerves (that extend from the brain) and spinal nerves (that extend from the spinal cord). The autonomic nervous system (ANS) controls and coordinates the functions of the body’s vital organs, such as heartbeat and rate of breathing — functions we don’t even think about.
By | Shimaa Mamdoh