Some people would say that the legs, arms, hands, eyes, mouth, ears and nose are important parts of the body. However, to sustain life, the most important parts of the body are internal parts. Without properly functioning internal parts, your body cannot function correctly and quality of life is altered.
The brain controls the nervous system. The brain functions include emotion, thought, memory, speech, sensory integration and reception, coordination and muscle control. The human brain has billions of nerve cells called neurons which are connected to more neurons though synapses. There are three main parts to the brain: the brain stem, which is connected to the spinal cord and controls heartbeat, breathing and digestion; the cerebellum, which controls coordination and balance; and the cerebrum, which controls senses including touch, vision and hearing.
The heart is the organ that keeps the blood flowing through the body’s blood vessels and arteries with rhythmic and repeated contractions. The upper two chambers in the heart are the right and left atria, and the lower two chambers of the heart are the right and left ventricles. The left and right sides of the heart are divided by the septum. The human heart has four valves that regulate blood flow. The tricuspid controls the blood flow between the right ventricle and right atrium and the pulmonary valve controls the blood flow from the right ventricle to the pulmonary arteries, which in turn carry the blood to the lungs for oxygenation. The mitral valve carries oxygen-rich blood from the lungs to the left ventricle and left atrium. The aortic valve is the largest artery that delivers blood to the entire body.
Located in the chest cavity, the lungs provide oxygen to the blood stream when air is inhaled and exhales carbon dioxide. After the blood is oxygenated, it is returned to the heart via the pulmonary vein. The right and left sides of the lung have the anterior lobe, medial lobe and posterior lobe. The right side has the accessory lobe, which is very small and associated with the right-side posterior lobe.
The kidneys maintain the chemical balance in the body by excreting excess fluid and waste products in the form of urine. The human body can survive with one kidney, but when one or both kidneys are not functioning correctly, dialysis is needed to artificially simulate kidney functions in ridding the body of fluid and waste removal.
The liver maintains a proper level of glucose in the blood, filters harmful substances, produces urea and breaks down fats in the body. The basic function of the liver is to keep the composition of the blood the same as it needs to be in a healthy person.