The Respiratory System - Assignment Example

Lungs and open airways are the fundamental components of human respiration. Air gets into and leaves the body via the nose. The nasal lining is has hairs and a mucous lining that helps to filter out solid particles that are contained in the inhaled air. Air moves to the pharynx from the nasal cavity. Pharynx opens to larynx which is an air way and the esophagus that leads to the stomach. At this point, an epiglottis closes the respiratory tract when swallowing food to prevent it from entering the respiratory system by way of trachea (Starr & McMillan, 2012).

Trachea divides into two major airways referred to as bronchus, with each entering one lung. Bronchi further divide in the lungs to form several bronchioles. The bronchioles have air sacs referred to as alveoli. Each lung is made up of approximately 150 million alveoli. Through these air sacs is where air exchange between lungs and blood circulation system takes place. Oxygen that has been inhaled crosses the thin walls of the alveoli to the blood supply system. Carbon dioxide that has been collected from all body organs also crosses this wall from the circulation system to lungs so that it is expelled from the body via the nose (Starr & McMillan, 2012).

Oxygen and carbon dioxide diffuse depending on their difference in concentration. Surface area in addition to partial pressure difference across the alveoli are the two major factors that affect the number of gas molecules that can move into and out the lungs in a given period of time. Hemoglobin present in red blood cells helps to facilitate the process of air exchange. Molecules of hemoglobin bind oxygen in the lungs where there is a high concentration of oxygen. Blood carries hemoglobin with bound oxygen to various body organs (Starr & McMillan, 2012).

In the body tissues, oxygen concentration is low as compared to concentration within blood