They bring oxygen into our bodies called inspiration, or inhalation and send carbon dioxide out called expiration, or exhalation. Air enters the respiratory system through the nose or the mouth. If it goes in the nostrils also called nares , the air is warmed and humidified. Tiny hairs called cilia SIL-ee-uh protect the nasal passageways and other parts of the respiratory tract, filtering out dust and other particles that enter the nose through the breathed air.
The two openings of the airway the nasal cavity and the mouth meet at the pharynx FAR-inks , or throat, at the back of the nose and mouth. The pharynx is part of the digestive system as well as the respiratory system because it carries both food and air. At the bottom of the pharynx, this pathway divides in two, one for food — the esophagus ih-SAH-fuh-gus , which leads to the stomach — and the other for air.
The epiglottis eh-pih-GLAH-tus , a small flap of tissue, covers the air-only passage when we swallow, keeping food and liquid from going into the lungs. The larynx, or voice box, is the top part of the air-only pipe. This short tube contains a pair of vocal cords, which vibrate to make sounds. Several cartilage structures make up the larynx and give it its structure.
The epiglottis is one of the cartilage pieces of the larynx and serves as the cover of the larynx during swallowing. The thyroid holds open the anterior end of the larynx and protects the vocal folds.
Inferior to the thyroid cartilage is the ring-shaped cricoid cartilage which holds the larynx open and supports its posterior end. In addition to cartilage, the larynx contains special structures known as vocal folds, which allow the body to produce the sounds of speech and singing.
The vocal folds are folds of mucous membrane that vibrate to produce vocal sounds. The tension and vibration speed of the vocal folds can be changed to change the pitch that they produce. The trachea, or windpipe, is a 5-inch long tube made of C-shaped hyaline cartilage rings lined with pseudostratified ciliated columnar epithelium. The trachea connects the larynx to the bronchi and allows air to pass through the neck and into the thorax.
The rings of cartilage making up the trachea allow it to remain open to air at all times. The open end of the cartilage rings faces posteriorly toward the esophagus, allowing the esophagus to expand into the space occupied by the trachea to accommodate masses of food moving through the esophagus. The main function of the trachea is to provide a clear airway for air to enter and exit the lungs.
In addition, the epithelium lining the trachea produces mucus that traps dust and other contaminants and prevents it from reaching the lungs. Cilia on the surface of the epithelial cells move the mucus superiorly toward the pharynx where it can be swallowed and digested in the gastrointestinal tract. At the inferior end of the trachea, the airway splits into left and right branches known as the primary bronchi.
The left and right bronchi run into each lung before branching off into smaller secondary bronchi. The secondary bronchi carry air into the lobes of the lungs—2 in the left lung and 3 in the right lung.
The secondary bronchi in turn split into many smaller tertiary bronchi within each lobe. The tertiary bronchi split into many smaller bronchioles that spread throughout the lungs. Each bronchiole further splits into many smaller branches less than a millimeter in diameter called terminal bronchioles.
Finally, the millions of tiny terminal bronchioles conduct air to the alveoli of the lungs. As the airway splits into the tree-like branches of the bronchi and bronchioles, the structure of the walls of the airway begins to change. The primary bronchi contain many C-shaped cartilage rings that firmly hold the airway open and give the bronchi a cross-sectional shape like a flattened circle or a letter D.
As the bronchi branch into secondary and tertiary bronchi, the cartilage becomes more widely spaced and more smooth muscle and elastin protein is found in the walls. The bronchioles differ from the structure of the bronchi in that they do not contain any cartilage at all. The presence of smooth muscles and elastin allow the smaller bronchi and bronchioles to be more flexible and contractile. The respiratory system does two very important things: it brings oxygen into our bodies, which we need for our cells to live and function properly; and it helps us get rid of carbon dioxide, which is a waste product of cellular function.
The nose, pharynx, larynx, trachea and bronchi all work like a system of pipes through which the air is funnelled down into our lungs. There, in very small air sacs called alveoli, oxygen is brought into the bloodstream and carbon dioxide is pushed from the blood out into the air. When something goes wrong with part of the respiratory system, such as an infection like pneumonia , it makes it harder for us to get the oxygen we need and to get rid of the waste product carbon dioxide.
Common respiratory symptoms include breathlessness , cough , and chest pain. When you breathe in, air enters your body through your nose or mouth. From there, it travels down your throat through the larynx or voicebox and into the trachea or windpipe before entering your lungs. All these structures act to funnel fresh air down from the outside world into your body.
The upper airway is important because it must always stay open for you to be able to breathe. It also helps to moisten and warm the air before it reaches your lungs. Structure The lungs are paired, cone-shaped organs which take up most of the space in our chests, along with the heart. Their role is to take oxygen into the body, which we need for our cells to live and function properly, and to help us get rid of carbon dioxide, which is a waste product. We each have two lungs, a left lung and a right lung.
The right lung has three lobes but the left lung has only two, because the heart takes up some of the space in the left side of our chest. These are pyramidal-shaped areas which are also separated from each other by membranes. There are about 10 of them in each lung. Each segment receives its own blood supply and air supply.
How they work Air enters your lungs through a system of pipes called the bronchi. These pipes start from the bottom of the trachea as the left and right bronchi and branch many times throughout the lungs, until they eventually form little thin-walled air sacs or bubbles, known as the alveoli.
Our lungs remove the oxygen and pass it through our bloodstream, where it's carried off to the tissues and organs that allow us to walk, talk, and move. Our lungs also take carbon dioxide from our blood and release it into the air when we breathe out. Small openings connect them to the nasal cavity. The sinuses help to regulate the temperature and humidity of the air your breathe in, as well as to lighten the bone structure of the head and to give tone to your voice.
The hairs that line the inside wall are part of the air-cleansing system. When your adenoids interfere with your breathing, they are sometimes removed.
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