The Respiratory System Class Starter Questions: 1)What is the purpose of the respiratory system? 2)Explain the difference between breathing and respiration. 3)What organs make up the respiratory system? Write them in order through which air passes during inhalation.

1) What is the purpose of the respiratory system? To provide a constant supply of oxygen to keep your body cells functioning To remove carbon dioxide from the body cells

2) Explain the difference between breathing and respiration. Breathing is: Moving air in and out of the lungs Respiration is: A chemical reaction that releases energy reactants: glucose + oxygen  products: carbon dioxide + water + energy

What is the pathway air takes through the respiratory system? Nose & mouth Pharynx Trachea Bronchi Bronchioles Alveoli Capillaries

Mouth & Nose This is where the oxygen first enters your body and also where carbon dioxide leaves. When the air comes into your nose it gets filtered by tiny hairs Your mouth does not contain these hairs therefore breathing by your mouth does not filter the air as well as breathing by your nose

Nasal cavity Warms & moistens air Glands that produce sticky mucus line the nasal cavity –traps dust, pollen, and other materials that were not trapped by nasal hairs

Pharynx Tube-like passageway used by food, liquid, and air At the lower end of the pharynx is a flap of tissue called the epiglottis –covers the trachea during swallowing so that food does not enter the lungs

Larynx “Voice box” The airway to which two pairs of horizontal folds of tissue, called vocal cords, are attached When we exhale, the vocal cords vibrate which produces sound

Trachea Air-conducting tube Connects the larynx with the bronchi Lined with mucus membranes and cilia Contains strong cartilage rings to hold the airway open at all times

Bronchi Two short tubes that branch off the lower end of the trachea Carry air into the lungs. Singular - bronchus

Lungs The lungs are spongy organs which contain the bronchioles and alveoli. Where gas exchange occurs There are 2 lungs (right and left)

Smoker’s Lung vs. Healthy Lung

Bronchioles Tiny branches of air tubes in the lungs Connect bronchi to alveoli

Alveoli Tiny, thin-walled, grapelike clusters at the end of each bronchiole Surrounded by capillaries Where exchange of carbon dioxide and oxygen (via diffusion) takes place Singular - alveolus

Pleura A double membrane that lines the lungs and adheres to the walls of the rib cage Diaphragm Dome shaped muscle between the chest and the abdomen that the body uses for breathing

Gas Exchange- What is it? Two gases, O 2 and CO 2 switch places O 2 moves from the alveoli to the capillaries CO 2 moves in the opposite direction, from the capillaries to the alveoli This occurs by diffusion: –The movement of molecules from a region of high concentration to a region of low concentration

Diffusion of Carbon Dioxide Blood arriving at the alveolus is deoxygenated: –Low in O2 –High in CO2 The concentration of CO2 inside the alveolus is lower than in the cappilary Thus, CO2 diffuses into the alveolus

Diffusion of Oxygen Blood arriving at the alveolus has a low concentration of O2 But air entering the alveolus has a high concentration of O2 Thus, O2 diffuses from the alveolus (high conc.) into the capillary (low conc.) Oxygenated blood leaving the alveolus

How does breathing work? Breathing is an involuntary action meaning that it occurs without conscious thought However, breathing is in fact controlled by a structure in the brain called the medula

Breathing Rate Breathing rate = # of breaths (including inhalation AND exhalation) in 1 min Your brain controls your breathing rate by monitoring the level of CO2 in your body When CO2 levels are high, breathing rate increases When CO2 levels are low breathing rate decreases

Why does your breathing rate increase during and after exercise? Physical activity requires increased energy production Thus, your muscles must consume more O2 to release more energy As a result of respiration, more CO2 is produced The increased levels of CO2 in the blood flowing to your brain is a signal to the medulla to increase breathing rate WHY? –To remove CO2 and replenish O2 at a faster rate – when.htmlhttp:// when.html