The Anatomy of the Respiratory System and Asthma
The respiratory system consists of organs that oversee inhaling of oxygen, exchanging gases, and exhaling of carbon dioxide. There are two different types of respiration, external and internal. External is considered the first round of gas exchange, it is between the lungs and pulmonary capillaries; this is where blood becomes oxygenated and is ready to spread through the body (Sullivan & Childress, p.75). Internal respiration or the second gas exchange, involves the systemic capillaries and body cells; tissues are relieved of carbon dioxide and rejuvenated with necessary oxygen for regular processes (Sullivan & Childress, p. 75). The anatomical and physiological processes and functions of the system are key in keeping the body and cardiovascular system in check.
In early October, I conducted an additional dissection outside of lab on a “sheep pluck. It consisted of a sheep’s trachea, heart, and lungs. It was incredible seeing the direct interaction between the heart and lungs. The initial cut was to remove the fatty, visceral pericardium to reveal a pristine heart. The pulmonary trunk branched off and led into both lungs. From here, I disconnected the heart while keeping the leading veins and arteries in tact with the lungs. A coronal cut was made down the two lobes of the left lung. This revealed the brachial tree leading from the primary bronchi, to bronchioles, to the terminal and respiratory bronchioles. Though they cannot be seen with the naked eye, the terminal bronchioles lead directly to the alveoli, the microscopic air sacs are directly involved with internal respiration within the lungs. The trachea contains rings of tracheal cartilage that follow through to the ends of the terminal bronchioles. The hyaline cartilage helps keep the lumen of the trachea from being closed off easily. Airways are always open. The overall organization of the lower respiratory could be described as hierarchical in the sense that it leads from largest structures to the smallest. Though the lungs themselves are asymmetrical in lobe count (left having two, right having three): “the main goal of mechanical ventilation is to help restore gas exchange and reduce the work of breathing (Cabello & Mancebo, p. 1311). The connection between the trachea, lungs, and heart are created this way to relieve the body of additional work that could potentially strain the organs themselves or the organism.
How it works
Though there are many diseases regarding the respiratory system, there is one in particular that is of interest to me: asthma. Asthma can be described as, “variable respiratory symptoms and variable airflow limitation; affecting over 334 million individuals, this non-communicable disease is a very common, chronic condition (Papi, Brigntling, Pedersen, Reddel, p. 783).