The Respiratory System Chapter 2

What is the main purpose of the respiratory system? GAS EXCHANGE –Inhaling oxygen, exhaling carbon dioxide Your LUNGS are an important organ of this system They deliver oxygen for cellular respiration and excrete carbon dioxide.

Let’s Follow the Journey of Air… INHALING How does air come in? –Through the MOUTH or NOSE Your nose has an important role: it warms the air and filters dust and particles. Your nose has cilia (tiny hairs) and mucus that help filter

Why breathe through your NOSE? The CILIA and MUCUS in your nose trap dust and particles! They get rid of this stuff by pushing it out (sneezing!) or pushing it down the esophagus (into your digestive system).

Fastest sneeze on record? 165 km/hr!!!

Air Enters Into the Nasal Cavity Air enters through the nasal cavity Once in, it needs to get to the lungs The epiglottis (little flap) opens to let air into the larynx (voice box) Then air goes into the airway called the trachea

The Fork in the Road Imagine the air on it’s path to the lungs is like a car on the road At the end of the trachea, air reaches a “fork in the road” Two tubes called BRONCHI take air to each lung

In the LUNGS…. Now the air has entered the lungs! The bronchi branch off into smaller tubes called bronchioles At the end of these tubes are little sacs called alveoli. There a millions of these little sacs in the lungs

Gas Exchange in the Alveoli This is where our respiratory and circulatory systems interact! Recall: blood travels from the heart to the lungs to get oxygen Gas exchange occurs at the alveoli in the lungs The alveoli are surrounded by capillaries (blood vessels)

Gas Exchange Cont’d There are approx. 700,000 alveoli in the human lung. They have stretch receptors that signal when the alveoli are full enough (stretched). They send a message to the brain to start breathing out.

Gas Exchange Cont’d Carbon dioxide diffuses from the capillaries into the alveoli Oxygen diffuses from the alveoli into the blood (binds to red blood cells) Blood is now oxygenated and can return to the heart

Diffusion in the Alveoli

Our Systems Working Together Both these systems work together to make sure that our body cells get the oxygen they need to keep us alive! The process of “gas exchange” occurs –In our lungs (at the alveoli) –In our body cells Gas exchange happens by DIFFUSION

Smoking = Unhealthy Lungs Smoking is a dangerous habit How many chemicals are in a cigarette? –Over 4000! How many of these can cause cancer? About 50 of them

Smoking and Cancer… 1.Lung Cancer Lung cancer is the leading cause of death in Canada (of both men and women) In 2005, approximately 19,000 people died of lung cancer 2. Emphysema Causes the alveoli walls to lose elasticity (breathing becomes difficult) 3. Mouth and Throat Cancer Not just lung cancer, smoking can cause cancer of the mouth and/ or throat

A Smoker’s Lung…

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.

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.

You-tube video Mouth cancer YouTube - Graphic Australian Anti- Smoking Ad

Smoking and Heart Disease 4. Heart Disease Smoking is also linked to heart disease –Heart must work harder –Levels of oxygen in the blood decreased –Carbon monoxide and other gases replace oxygen in the blood –Can cause damage to the heart –Decreased size of blood vessels due to FATTY DEPOSITS that build up inside

You-tube Video Clogged arteries (fatty deposits) –YouTube - anti-smokingYouTube - anti-smoking

One last one… YouTube - Star Wars Anti Smoking Ad