The Respiratory System and Its Disorders
Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss in Understanding Medical Terms, 2020
Within the lungs, the left and right bronchi branch into smaller and smaller passageways. As these tubes become small enough to remain barely visible without a microscope, they still contain the cartilage rings found in the trachea and left and right bronchi, so they are still referred to as bronchi. As the size continues to decrease, however, only muscle tissue remains. These smallest branches are called bronchioles, meaning "little bronchi." Bronchioles terminate in small air sacs called alveoli from which oxygen passes into the bloodstream for transport throughout the body (Figure 9.1).
Overview on Anatomy of Human Respiratory System
Sunit K. Singh in Human Respiratory Viral Infections, 2014
The trachea (Figure 1.4a) or windpipe is about 12 cm long and 2.5 cm in diameter. It begins below the larynx near the sixth cervical vertebra and bifurcates into right and left primary bronchi at the level of the fifth thoracic vertebra. The trachea is supported on the anterior and lateral sides by about 16–20 incomplete C-shaped rings of hyaline cartilage. The dorsal wall of trachea facing the esophagus is membranous and has an incomplete portion of a cartilage ring. The rings prevent collapsing of tracheal wall inward. The free ends of incomplete tracheal rings are interconnected by trachealis muscle; it contracts to reduce the lumen of trachea to increase the force of airflow, as in coughing. The last tracheal ring projects inward to form a small internal ridge called the carina. The mucous membrane covering of carina is a very sensitive part of the respiratory system and is associated with the cough reflex.
The respiratory system
Laurie K. McCorry, Martin M. Zdanowicz, Cynthia Y. Gonnella in Essentials of Human Physiology and Pathophysiology for Pharmacy and Allied Health, 2019
The trachea and the primary bronchi contain C-shaped hyaline cartilage rings in their walls. The lobar bronchi contain plates of cartilage that completely encircle the airways. The cartilage in these large airways provides structural support and prevents the collapse of the airways. As the bronchi continue to branch and move out toward the lung periphery, the cartilage diminishes progressively until it disappears in airways that are about 1 mm in diameter. Airways with no cartilage are referred to as bronchioles. As the cartilage becomes sparser, it is replaced by smooth muscle. Therefore, the bronchioles, which have no cartilage to support them but do have smooth muscle capable of vigorous constriction, are susceptible to collapse under certain conditions, such as an asthmatic attack.
Nanoparticles as a potential teratogen: a lesson learnt from fruit fly
Published in Nanotoxicology, 2019
Bedanta Kumar Barik, Monalisa Mishra
Only handfuls of literature are available which expose NP through the respiratory route. NPs present in the environment may enter into the human body via the respiratory tract. In Drosophila respiratory organ, the trachea is formed by fusion of 10,000 tubules which are interconnected with each other (Gervais et al. 2012). The genes involved in the trachea development share similarity with vertebrates (Horowitz and Simons 2008). Furthermore, unlike mammalian trachea Drosophila trachea is formed of only single type of epithelial cells and thus offers the system acts like a cell culture system within Drosophila (Horowitz and Simons 2008). Further the structure of the trachea allows it to be used for various respiratory-related issues of vertebrates (Pandey and Nichols 2011b). To mimic the effect of NPs internalized via respiratory system, Posgai et al. (2009) developed a method to study the effect of NPs via respiratory tract of Drosophila. They exposed fluospheres, red fluorescent CdSe/ZnS nanoparticles and silver nanoparticles into tracheal-specific (breathless) GFP reporter strain of Drosophila. This method was known as a nebulizer nanoparticle delivery system which later known as direct microtransfer method (Vega-Alvarez et al. 2014). This method ensures the uniform release of NP to the specific target without any tissue damage. Furthermore, it allows to determine the minimum toxic dose in a large number of replicates with less risk of false-positive results.
Navigation system for percutaneous tracheotomy
Published in Acta Oto-Laryngologica, 2021
Johan Ullman, Jonas Karling, Rusana Bark, David Nelson, Michael Wanecek, Gregori Margolin
In our experience, if the patient is properly intubated and the cuff correctly inflated, the tube glides easily to a subglottic position when being retracted. Additionally, when withdrawn further whilst still inflated, the tube and cuff easily pass between the vocal cords. This was confirmed when measuring the cuff pressure with a manometer, and it was noted that the pressure was diminished when the cuff passed the vocal cords. The reason for this is found in the fact that the most narrow and rigid passage in the trachea is the cricoid cartilage and the 1st tracheal ring. Given that the cuff comfortably passes this portion, there is no problem to also pass the vocal cords easily, and in our experience non-traumatically, give way for the cuff in the anesthetized and relaxed patient. In aggregate, there is no need to uncuff the tube (as long as the cuff pressure is within recommended levels). In this way air leakage can be avoided. In contrast to conventional PDT technique, the rigid SafeTrach system helps to keep the cuff in position (about half the cuff in between or above the vocal cords).
Tracheotomy as a surgical access for removal of bullet in the trachea: A case report
Published in Alexandria Journal of Medicine, 2018
Shankar Ramasundram, Baharudin Abdullah, Sivakumar Kumarasamy, Nurul Syamiza Shamsudin
Rigid bronchoscopy was performed under general anesthesia. However, no foreign body was seen in the airway. Neck exploration was performed through the puncture wound. The wound was extended through the strap muscle and anterior wall of trachea. Injury over the posterior wall of trachea was also visible. However, no foreign body was visualized during the exploration. Tracheotomy was performed. Mucous secretion within the lumen sucked out carefully while looking for the foreign body. Initial inspection after a stoma was created on the trachea revealed no foreign body as well. However, palpation using a blunt probe felt grittiness along the posterior wall of trachea. Upon manipulation, a small piece of metal was seen projecting from the trachea. The metallic fragment was removed with forceps and tracheostomy tube was inserted. Inspection of the foreign body revealed metallic fragment of a bullet measuring around 0.8 cm in length (Fig. 2). He tolerated the procedure well and was nursed in general ward post operatively. Tracheostomy was decanulated on day 3 post surgery successfully and he was subsequently discharged.