Respiratory System

Respiratory system:

The respiratory system is a combination of the Circulatory and Pulmonary systems feeding oxygen and nutrients to cells all around the body. These systems allow oxygen to enter the body, and be circulated around the body at a varying rate. These two systems work in conjunction with each other and have various rates of operation that are usually in as close a correlation as possible.

Circulatory System:

The circulatory system’s primary responsibility is to circulate oxygenated and deoxygenated blood around the body. The Circulatory system consists of the Heart working in conjunction with arteries and veins. The Heart pumps oxygenated blood through arteries to the cells of the body, and then pumps out the de-oxygenated blood, which contains CO2 to the Lungs in the pulmonary system to release their CO2 and gain O2 to pump back to the cells of the body. The circulatory system also helps remove waste from the cells such as Lactic Acid, which is pumped to the lymphatic system and then expelled from the body.

Pulmonary System
The main organ in the pulmonary system is the lung, and rightly so as the pulmonary system’s main task is to oxygenate, and deoxygenate human blood at a varying rate. This is harder than it sounds, as inflating the lungs is a much more complicated process than many think. It involves the use of 3 main muscles, the diaphragm, and the internal and external intercostal muscles, which lye between and behind the ribs. The chest cavity is naturally sealed, so when the volume of the chest cavity expands, the pressure drops. This increase in volume is achieved through the contraction of the diaphragm muscle and the external intercostal muscles contract while the internal intercostal muscles relax to physically expand the chest cavity up and outward. This creates a lower pressure inside the chest cavity than the outside environment, causing air to rush in. Air rushes into the lungs from the exterior environment through the mouth and/ or nasal cavities. At a usual respiratory rate, air is normally solely inhaled through the nasal cavity so that the nasal hairs and capillaries in the nose may filter and warm the air, making it more suitable for pulmonary intake; the utilization of both cavities is only warranted when oxygen debt is increasing exponentially in relation to pulmonary intake such as during rigorous exercise. After being inhaled through the mouth and nasal cavities the outside air passes through the pharynx where the air is further filtered, warmed, and moistened before entering the lungs. From the pharynx, air flows down the esophagus and through the larynx, the larynx is commonly known as the voice box and contains the vocal cords so that humans can talk, the larynx also protects the trachea from material induction such as food. From the larynx the air moves into the trachea and down into the bronchioles which split the air up and send it equally to both lungs. Once the air enters the lungs it flows into the alveoli, the alveoli are small air sacs inside the lung, situated in close proximity to capillaries and have an extremely thin membrane which allows oxygen to diffuse out of the blood. The alveoli also extract Carbon Dioxide (CO2), which diffuses from the blood into the alveoli, and is expelled during the expiration process. Expiration is naturally the reverse of inhalation; the diaphragm relaxes, as do the external intercostal muscles, however, the internal intercostal muscles contract and cause the chest cavity to grow smaller in internal volume, this forces carbon dioxide and other waste gasses out of the lungs. Air flows out through the bronchioles, up through trachea, and back through the larynx, where it may be run through the vocal chords in the larynx to create sound for speech. The larynx also controls the rate at which the air escapes from the lungs, the rate on exhalation is especially controlled, and varies with oxygen debt and strain on the pulmonary system; increased oxygen demand will result in a completely relaxed larynx for expedient CO2 dismissal to increase the rate of oxygen intake. From the larynx the de-oxygenated air travels up the esophagus and through the mouth and nose, normally it exits through the nose, but during periods of increased pulmonary demand, air may be exhaled through the mouth as well.