Category: GENERAL KNOWLEDGE

We are continuously inhaling the gas known as oxygen-without it, we would die. Oxygen plays a vital role in breaking down nutrients such as glucose that need to be transported to various locations to provide the body with energy. This process is known as cell respiration.

The energy produced through cell respiration is contained in a molecule that is called ATP, which stands for adenosine triphosphate. ATP can be thought of as the fuel required for various cellular processes to occur throughout the body.

In addition to producing ATP, cell respiration also produces carbon dioxide. So while oxygen is inhaled, carbon dioxide is exhaled, and is con sidered a waste product. It is exhaled because it is a waste product of cell respiration. Like other waste products that are covered throughout this book, carbon dioxide must leave the body. If carbon dioxide builds up in the body, it can disrupt the chemical balance in the body. This can cause acidosis, when fluid becomes too acidic, which can result in calcium deposits in the body’s soft tissue. Carbon dioxide buildup in the body is toxic to the heart.

Water, which scientists estimate comprises approximately 60 to 75 percent of the human body, is important for three primary reasons: it acts as a solvent, it acts as a lubricant, and because it changes temperature slowly, it is vital in regulating the body’s temperature. The first reason because it is a solvent-means that many substances can dissolve in it, which allows nutrients and other vital components to be transported throughout the body. This is because the body’s main transportation systems, blood, are largely composed of water.

Therefore, substances like glucose (which comes from food) that are needed for energy in the body can be dissolved in the blood and then delivered to the heart and cells. Another important function is the elimination of waste. Materials that the body does not need, called waste products, are dissolved in the water component of urine and then flushed out of the body through the urinary system.

In addition to acting as a solvent, water is a lubricant, which means it prevents friction between the various surfaces inside the body, such as bones and blood vessels. One example of water acting as a lubricant is in the diges tive system. One of the fluids present in this system is the fluid mucus, which, like blood, is primarily made up of water. Mucus enables food to move through the intestines and be digested, providing the body with fuel.

The third function of water in the body is that of a temperature regulator. The temperature of water does not change quickly-it has to absorb a lot of heat or lose a lot of heat before the temperature increases or drops. This property enables the body to stay at a fairly constant temperature. In addition, water does an important cooling job for the body in the form of perspiration. When the body is absorbing an excess amount of heat, sweat forms on the skin, which allows the heat to escape the body without damaging any cells.

The Respiratory System: The primary organs are located in two areas: the upper and lower respiratory tracts. The upper tract contains the nose and nasal cavity (also known as the nasal passage), the pharynx (or throat), and the larynx (or voice box).

The lower respiratory tract contains the trachea (windpipe), the bronchi, the alveoli, and the lungs. This system’s major responsibility is to control and regulate the breathing process, which involves moving air into and out of the lungs.

The Nervous System: The primary organs of the nervous system are the brain and spinal cord. Through the nervous system’s two divisions, the central nervous system (CNS) and the peripheral nervous system (PNS), stimuli and other information is processed into the form of reaction and activity.

In addition to the endocrine system, the nervous system is known as one of the body’s key communication centers. This communication is done through nerve impulses that travel through the body’s nerve fiber system.

The Muscular System: Three types of muscles make up this system: the skeletal muscle, which helps the body to move; the smooth muscle, which is associated with the internal muscles; and cardiac, which works to help the heart to function.

The movement of each of these muscles is determined by direction they receive from different areas of the body. Specifically, the autonomic nervous system controls the smooth and cardiac muscles and the central nervous system controls the central nervous system.

The Lymphatic System: The primary organs of this system are the bone marrow and thymus, while the secondary organs are the spleen, tonsils, adenoid, Peyer’s patches, and appendix.

The lymphatic system’s job is to protect the body against toxins and other potentially harmful substances that can cause illness and disease. While not an organ, one of this system’s most important components are lymphocytes. These specialized cells detect organisms that might be harmful to the body and then prompt an immune response to drive them out of the body.