How the Lungs Work | National Heart, Lung, and Blood Institute (NHLBI)
The relationship between gas pressure and volume helps to explain the mechanics of Inhalation and exhalation: The lungs, chest wall, and diaphragm are all. The diaphragm in the respiratory system is the dome-shaped sheet of muscle The lungs are enclosed in a kind of cage in which the ribs form the sides and the . When you're physically active, your abdominal muscles contract and push your diaphragm against your lungs even more than usual.
They also carry carbon dioxide, a waste gas, out of your lungs.
The airways include your: Nose and linked air passages called nasal cavities Mouth Larynx LAR-ingksor voice box Trachea TRA-ke-ahor windpipe Tubes called bronchial tubes or bronchi, and their branches Air first enters your body through your nose or mouth, which wets and warms the air. Cold, dry air can irritate your lungs. The air then travels through your voice box and down your windpipe. The windpipe splits into two bronchial tubes that enter your lungs.
A thin flap of tissue called the epiglottis ep-ih-GLOT-is covers your windpipe when you swallow. This prevents food and drink from entering the air passages that lead to your lungs.
Except for the mouth and some parts of the nose, all of the airways have special hairs called cilia SIL-e-ah that are coated with sticky mucus. The cilia trap germs and other foreign particles that enter your airways when you breathe in air. These fine hairs then sweep the particles up to the nose or mouth. From there, they're swallowed, coughed, or sneezed out of the body. Nose hairs and mouth saliva also trap particles and germs. Lungs and Blood Vessels Your lungs and linked blood vessels deliver oxygen to your body and remove carbon dioxide from your body.
Diaphragm in Respiratory System
Your lungs lie on either side of your breastbone and fill the inside of your chest cavity. Your left lung is slightly smaller than your right lung to allow room for your heart. Within the lungs, your bronchi branch into thousands of smaller, thinner tubes called bronchioles. These tubes end in bunches of tiny round air sacs called alveoli al-VEE-uhl-eye. Each of these air sacs is covered in a mesh of tiny blood vessels called capillaries. The capillaries connect to a network of arteries and veins that move blood through your body.
The pulmonary PULL-mun-ary artery and its branches deliver blood rich in carbon dioxide and lacking in oxygen to the capillaries that surround the air sacs. Inside the air sacs, carbon dioxide moves from the blood into the air. At the same time, oxygen moves from the air into the blood in the capillaries. The oxygen-rich blood then travels to the heart through the pulmonary vein and its branches. The heart pumps the oxygen-rich blood out to the body.
The lungs are divided into five main sections called lobes. Some people need to have a diseased lung lobe removed. However, they can still breathe well using the rest of their lung lobes. Muscles Used for Breathing Muscles near the lungs help expand and contract tighten the lungs to allow breathing. These muscles include the: Diaphragm DI-ah-fram Abdominal muscles Muscles in the neck and collarbone area The diaphragm is a dome-shaped muscle located below your lungs.
- Diagram of the Human Respiratory System (Infographic)
- Diaphragm and lungs
- Diaphragm in Respiratory System
It separates the chest cavity from the abdominal cavity. The diaphragm is the main muscle used for breathing. The intercostal muscles are located between your ribs.
They also play a major role in helping you breathe. Beneath your diaphragm are abdominal muscles. They help you breathe out when you're breathing fast for example, during physical activity. Muscles in your neck and collarbone area help you breathe in when other muscles involved in breathing don't work well, or when lung disease impairs your breathing.
What Happens When You Breathe? Breathing In Inhalation When you breathe in, or inhale, your diaphragm contracts tightens and moves downward.
Control of Breathing - Lung and Airway Disorders - MSD Manual Consumer Version
This increases the space in your chest cavity, into which your lungs expand. The intercostal muscles between your ribs also help enlarge the chest cavity.
They contract to pull your rib cage both upward and outward when you inhale. 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 finally reaches and enters the alveoli air sacs.
Through the very thin walls of the alveoli, oxygen from the air passes to the surrounding capillaries blood vessels. A red blood cell protein called hemoglobin HEE-muh-glow-bin helps move oxygen from the air sacs to the blood.
At the same time, carbon dioxide moves from the capillaries into the air sacs.
The gas has traveled in the bloodstream from the right side of the heart through the pulmonary artery. Oxygen-rich blood from the lungs is carried through a network of capillaries to the pulmonary vein. This vein delivers the oxygen-rich blood to the left side of the heart.
The left side of the heart pumps the blood to the rest of the body. There, the oxygen in the blood moves from blood vessels into surrounding tissues.
Breathing Out Exhalation When you breathe out, or exhale, your diaphragm relaxes and moves upward into the chest cavity. The intercostal muscles between the ribs also relax to reduce the space in the chest cavity. As the space in the chest cavity gets smaller, air rich in carbon dioxide is forced out of your lungs and windpipe, and then out of your nose or mouth.
Breathing out requires no effort from your body unless you have a lung disease or are doing physical activity. As the diaphragm contracts, it increases the length and diameter of the chest cavity and thus expands the lungs.
The intercostal muscles help move the rib cage and thus assist in breathing.560 FA LUNG RELATIONS, DIAPHRAGM,RESP MUSCLES
The process of breathing out called exhalation or expiration is usually passive when a person is not exercising. The elasticity of the lungs and chest wall, which are actively stretched during inhalation, causes them to return to their resting shape and to expel air out of the lungs when inspiratory muscles are relaxed.
Therefore, when a person is at rest, no effort is needed to breathe out. During vigorous exercise, however, a number of muscles participate in exhalation. The abdominal muscles are the most important of these. Abdominal muscles contract, raise abdominal pressure, and push a relaxed diaphragm against the lungs, causing air to be pushed out.
The muscles used in breathing can contract only if the nerves connecting them to the brain are intact. In some neck and back injuries, the spinal cord can be severed, which breaks the nervous system connection between the brain and the muscles, and the person will die unless artificially ventilated.
To equalize the pressure, air enters the lungs.