What is Respiratory system?
Respiratory system meaning The respiratory system consists of those organs and parts of the body that make it possible to breathe. Respiration can be divided into two distinct phases: external respiration and internal respiration.External respiration involves both inspiration (inhaling) and expiration (exhaling) of air. Inspiration is the means by which oxygen is carried from the air into the lungs and then into the blood. Expiration is the means by which carbon dioxide is returned from the blood to the lungs and then expelled into the air.Internal respiration is concerned with the exchange of oxygen and carbon dioxide at the tissue level: the passage of oxygen from the blood to the tissues and the return of carbon dioxide from the tissues to the blood. First the oxygen is carried from the lungs by the red blood cells. Then carbon dioxide is carried by the red blood cells to the lungs. The utilization of oxygen and the elimination of carbon dioxide by the cells is called cellular respiration.The respiratory system begins with the nose: at the other end of the system are the lungs. In between the nose and lungs are the nasopharynx, oropharynx, larynx, trachea and bronchi. The thorax, which houses most of the organs of the respiratory system, plays a major role in respiration. The elliptical shape of the ribs and the angle of their attachment to the spine allows the thorax to expand during inspiration. Thus, the lungs provide a place where large amounts of oxygen can be taken from the air and quickly absorbed into the bloodstream. Conversely, large amounts of carbon dioxide are discharged into the lung where it is exhaled.