The Respiratory System

Interesting Facts The right lung is slightly larger than the left. Hairs in the nose help to clean the air we breathe, as well as warming it. The highest recorded "sneeze speed" is 165 km per hour. The surface area of the lungs is roughly the same size as a tennis court.

More Interesting Facts The capillaries in the lungs would extend 1,600 kilometres if placed end to end. We lose half a litre of water a day through breathing. This is the water vapour we see when we breathe onto glass. A person at rest usually breathes between 12 and 15 times a minute. The breathing rate is faster in children and women than in men.

The Parts

The Lungs http://video.about.com/lungdiseases/How-Lungs-Function.htm

The Nasal Sinus The Nasal Sinus is surrounded by a lot of capillary beds and mucous glands. Because it is one of the major entry ways into the body it has many things to help keep us safe Nose hairs: with the aid of mucous, these hairs filter and trap debris. The debris that is trapped in this manner is discharged through the nose. There are many white blood cells here to recognize and destroy foreign objects. Histamines are released here as an allergic response when foreign irritants are encountered. This causes runny nose.

Pharynx/Throat This is the common passageway for air and food

Epiglottis This is a flap of tissue that covers the top of the trachea when swallowing to ensure that food enters the esophagus and not the lungs.

Larynx When the epiglottis is opened, the air is able to pass through the larynx (voice box) and into the trachea. The larynx contains the vocal cords (two tendons that adjust the pitch of sounds according to how taut they are).

When a guy goes through puberty, his vocal chords and voice box (larynx) grow larger, and begins to stick out at the front of the throat. This lump is called the Adam's Apple.

Trachea This is the windpipe. This passageway is held open by the presence of C-shaped rings of cartilage. This is a protective adaptation. The trachea conducts air into the bronchi.

Cilia and mucus filter the air as it moves through the trachea. The mucous traps the dirt and other particles, and the cilia push it to the back of the throat so we swallow it into our digestive system

Bronchi The trachea splits into two bronchi and takes the air into each lung. These branches also have cartilage around them, for the same reason. The bronchi conducts air into smaller branching passageways called bronchioles.

Bronchioles The bronchioles are branching passageways that carry air to its ultimate destination, the alveoli.

Alveoli These are the blind sac-like endings at the end of the bronchioles. There are approx. 700,000 alveoli in the human lung. This is the site of gas exchange. Oxygen leaves the alveoli and moves into the blood to be taken around the body. Carbon dioxide does the opposite and is breathed out.

Why are they so special? Each adult lung contains millions of alveoli. This provides lots of surface area for the gases to be exchanged. The walls of alveoli are only one cell thick. They have stretch receptors that signal when the alveoli are full enough (stretched). They send a message to the brain to start breathing out. They are very moist and this helps gas exchange. They are covered with a LOT of blood capillaries so oxygen and carbon dioxide can be exchanged efficiently.

Diaphragm This is a sheet of muscle that separates the chest cavity from the abdominal cavity. When you inhale it moves down. When you exhale it moves up.

Ribs and Muscles These are the bones that are connected to the vertebral column and sternum. These are muscles between the ribs, which help to move the ribs… Up and out when we inhale. Down and in when we exhale.

TO INHALE When the brain realizes there is too much carbon dioxide in our blood, it sends a message to the rib muscles and diaphragm to contract. The ribs move up and out, the diaphragm moves down. This creates more space in the lungs and air rushes in to fill that space. This is called inhalation.

TO EXHALE When the alveoli get too stretched (full of air), they send a message to the brain to stop inhaling. The brain tells the ribs to move back down and in, and the diaphragm moves back up. This decreases the amount of space in the lungs and the air is pushed out. This is called exhalation.

See a Working Respiratory System: http://www. smm

Problems With the Lungs Smoking causes lung cancer and emphysema Emphysema causes the alveoli to lose their elasticity People who have respiratory disease often have heart disease There are over 4000 chemicals in cigarettes Smoking also destroys the cilia lining in your respiratory system so that dirt and particles can’t be removed

Lung Cancer SMOKING POSTER CHILD http://www.tobaccofacts.org/poster/index.html ANIMATION: WHAT SMOKING DOES TO YOUR BODY http://www.mydr.com.au/default.asp?article=4215

Cancerous Lungs

What Else Can Go Wrong? Asthma: Over 20 million people have asthma in the US, and it's the number-one reason that kids and teens chronically miss school. Asthma is a long-term, inflammatory lung disease that causes airways to tighten and narrow when a person with the condition comes into contact with irritants such as cigarette smoke, dust, or pet dander. Bronchitis: Although bronchitis doesn't affect most teens, it can affect those who smoke. In bronchitis, the membranes lining the bronchial tubes become inflamed and an excessive amount of mucus is produced. The person with bronchitis develops a bad cough to get rid of the mucus. Common Cold: Colds are caused by over 200 different viruses that cause inflammation in the upper respiratory tract. The common cold is the most common respiratory infection. Symptoms may include a mild fever, cough, headache, runny nose, sneezing, and sore throat. Cystic Fibrosis (CF): CF is an inherited disease affecting the lungs. CF causes mucus in the body to be abnormally thick and sticky. The mucus can clog the airways in the lungs and make a person more likely to get bacterial infections.

Pneumonia is an inflammation of the lungs, which usually occurs because of infection with a bacteria or virus. Pneumonia causes fever, inflammation of lung tissue, and makes breathing difficult because the lungs have to work harder to transfer oxygen into the bloodstream and remove carbon dioxide from the blood. Although some respiratory diseases like asthma or cystic fibrosis can't be prevented, you can prevent many chronic lung and respiratory illnesses by avoiding smoking, staying away from pollutants and irritants, washing your hands often to avoid infection, and getting regular medical checkups.