The lungs and respiratory system allow us to breathe. They bring oxygen into our bodies (called inspiration, or inhalation) and send carbon dioxide out (called expiration, or exhalation). This exchange of oxygen and carbon dioxide is called respiration.
The respiratory system consists of all the organs involved in breathing. These include the nose, pharynx, larynx, trachea, bronchi and lungs.
What is the respiratory system? The respiratory system is the network of organs and tissues that help you breathe. It includes your airways, lungs, and blood vessels. The muscles that power your lungs are also part of the respiratory system.
In addition to the lungs, these organs include the pharynx, larynx, trachea and bronchi. The nasal cavity is also part of the respiratory system.
Air enters the body through the mouth or nose and quickly moves to the pharynx, or throat. From there, it passes through the larynx, or voice box, and enters the trachea. The trachea is a strong tube that contains rings of cartilage that prevent it from collapsing.
The main function of the lungs is the process of gas exchange called respiration (or breathing). In respiration, oxygen from incoming air enters the blood, and carbon dioxide, a waste gas from the metabolism, leaves the blood.
The organs of the respiratory system include the lungs, pharynx, larynx, trachea, and bronchi.
Tiny air sacs at the end of the bronchioles (tiny branches of air tubes in the lungs). The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out.
The smallest section of the bronchi are called BRONCHIOLES, at the end of which are the alveoli (plural of alveolus). The ALVEOLI are the very small air sacs that are the destination of air that you breathe in. The CAPILLARIES are blood vessels that are imbedded in the walls of the alveoli.
The functions of the respiratory system include gas exchange, acid-base balance, phonation, pulmonary defense and metabolism, and the handling of bioactive materials.
The major passages and structures of the upper respiratory tract include the nose or nostrils, nasal cavity, mouth, throat (pharynx), and voice box (larynx). The respiratory system is lined with a mucous membrane that secretes mucus.
Vital OrgansThey are the heart, brain, kidneys, liver, and lungs. The locations of these five organs and several other internal organs are shown in the figure below.
Summary Each lung is divided into lobes. The bronchial tree running through your lungs is made up of the windpipe, bronchi, bronchioles, and alveoli.
The respiratory system starts at the nose and mouth and continues through the airways and the lungs. Air enters the respiratory system through the nose and mouth and passes down the throat (pharynx) and through the voice box, or larynx.
The respiratory tract is divided into two main parts: the upper respiratory tract, consisting of the nose, nasal cavity and the pharynx; and the lower respiratory tract, consisting of the larynx, trachea, bronchi and the lungs. The upper respiratory tract consists of the nose, the nasal cavity and the pharynx.
The diaphragm in the respiratory system is the dome-shaped sheet of muscle that separates the chest from the abdomen. It is also referred to the thoracic diaphragm because it's located in the thoracic cavity, or chest.
There are five functions of the respiratory system.
- Gas Exchange – oxygen and carbon dioxide.
- Breathing – movement of air.
- Sound Production.
- Olfactory Assistance – sense of smell.
- Protection – from dust and microbes entering body through mucus production, cilia, and coughing.
If you have emphysema, your air sacs are damaged, and the smallest bronchial tubes collapse. This makes it hard for you to get oxygen into your blood and carbon dioxide out of your blood.
Sometimes you may swallow and cough because something “went down the wrong pipe.” The body has two “pipes” – the trachea (windpipe), which connects the throat to the lungs; and the esophagus, which connects the throat to the stomach.
The trachea, also called the windpipe, is part of the passageway that supplies air to the lungs. Any prolonged blockage, even for a few minutes, can cause death. The trachea is about 4.5 inches long and 1 inch in diameter, and is comprised of smooth muscle and several c-shaped rings of cartilage.
Why do we inhale oxygen and exhale carbon dioxide? The short answer is that you inhale oxygen because you need oxygen for some biological processes. A fairly important one is the production of ATP, the energy all of our cells use. In the process, electrons are used and oxygen has a high affinity for electrons.
First, a volume of air is inhaled. Second, the opening to the trachea (the epiglottis) closes as the chest constricts, compressing the air within the lungs. Third, the epiglottis opens, allowing a rapid burst of air to be expelled through the mouth.
Your nose connects to the back of your mouth through two tubes. The air you breathe in goes from your mouth and nose down to your trachea and into your lungs.
While the trachea and upper bronchi contain C-shaped cartilage, the smaller bronchi have "plates" of cartilage. As the bronchi subdivide into smaller (subsegmental) bronchi, the amount of cartilage decreases, and the amount of smooth muscle increases.
Tiny hairs called cilia, covering the walls of the air tubes, move the mucus upward and out into the throat, where it is either coughed up and spat out, or swallowed. The air reaches the tiny air sacs (alveoli) in the inner part of the lungs with any dust particles that avoided the defenses in the nose and airways.
Mucus and cilia are a primary defense mechanism for the lungs. If there is a problem with either the mucus or the cilia, the airways may become blocked and the harmful germs and particles can be trapped in the lungs, causing damage.
As your lungs expand, air is sucked in through your nose or mouth. The air travels down your windpipe and into your lungs. After passing through your bronchial tubes, the air travels to the alveoli, or air sacs.
The respiratory system does not work alone in transporting oxygen through the body. The respiratory system works directly with the circulatory system to provide oxygen to the body. Oxygen taken in from the respiratory system moves into blood vessels that then circulate oxygen-rich blood to tissues and cells.
The lower respiratory system, or lower respiratory tract, consists of the trachea, the bronchi and bronchioles, and the alveoli, which make up the lungs. These structures pull in air from the upper respiratory system, absorb the oxygen, and release carbon dioxide in exchange.
The diaphragm, located below the lungs, is the major muscle of respiration. It is a large, dome-shaped muscle that contracts rhythmically and continually, and most of the time, involuntarily. Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarges.
The circulatory system consists of three independent systems that work together: the heart (cardiovascular), lungs (pulmonary), and arteries, veins, coronary and portal vessels (systemic). The system is responsible for the flow of blood, nutrients, oxygen and other gases, and as well as hormones to and from cells.
Respiratory failure is a serious condition that develops when the lungs can't get enough oxygen into the blood. Buildup of carbon dioxide can also damage the tissues and organs and further impair oxygenation of blood and, as a result, slow oxygen delivery to the tissues.
The heart is the key organ in the circulatory system. As a hollow, muscular pump, its main function is to propel blood throughout the body.
Gas exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them. As shown below, inhaled oxygen moves from the alveoli to the blood in the capillaries, and carbon dioxide moves from the blood in the capillaries to the air in the alveoli.
