The Respiratory System https://www.youtube.com/watch?v=k4uNapAUCQU

Respiratory System Whether you know it or not you breath in and out about 15 times each minute. You move more than 10000L of air in and out of the lungs each day

Respiratory System Provides the oxygen needed by the body and removes the carbon dioxide produced as your body uses energy for growth, repair, and movement.

Modelling Asthma Take a straw and try breathing through it. How is this similar to someone who has asthma? What does the straw represent in terms of the structures of the respiratory system?

Respiration 1) The exchange of O2 and CO2 between the environment and the body 2) The process of cellular respiration that cells use to make ATP 3) Breathing to move air in and out of the body.

Respiration 1. Inhaling air containing O2 2. O2 moves (diffuses) from lungs to blood. 3. CO2 moves (diffuses) from blood to lungs 4. Exhaling air containing CO2

The Human Respiratory System Nasal cavity Path taken by air Path taken by food

The Human Respiratory System Part Function Special Features Nasal passages Point of entry Filter, warm, moisten air Mucus, hairs, Oral Cavity Warm and moisten air Alternate space for gas exchange, no filtration

The Human Respiratory System Nasal Cavity Path taken by air Path taken by food Pharynx Epiglottis Esophagus

The Human Respiratory System Part Function Special Features Pharynx connects nasal and oral cavity to larynx -Cilia in top portion -moves food towards mouth to be swallowed Epiglottis A flap that prevents food from entering the lungs by blocking the opening of trachea Small, flexible

The Human Respiratory System Nasal Cavity Path taken by air Path taken by food Pharynx Epiglottis Esophagus Trachea Upper Respiratory Tract Larynx

The Human Respiratory System Part Function Special Features Larynx Contains the vocal cords – for sound two flaps of cartilage, vibrate when air passes through Trachea Passage of air into 2 bronchi, “windpipe” filter particles up to mouth ~12cm long -Semicircular cartilage rings to prevent collapse -Cilia and mucus

The Human Respiratory System Nasal Cavity Path taken by air Path taken by food Pharynx Epiglottis Esophagus Trachea Bronchi Bronchioles Upper Respiratory Tract Larynx

The Human Respiratory System Part Function Special Features Bronchus Each carries air into lungs and splits into many bronchioles Full cartilage rings for support Bronchiole Many branches carry air to alveoli Able to change diameter to regulate air flow Smallest passageways to increase surface area

The Human Respiratory System Nasal Cavity Path taken by air Path taken by food Pharynx Epiglottis Esophagus Trachea Bronchi Bronchioles Alveoli Diaphragm Upper Respiratory Tract Larynx Lower Respiratory Tract

The Human Respiratory System Part Function Special Features Alveoli Site of gas exchange (O2 from inhaled air diffuses into capillaries and CO2 in blood diffuses into alveoli) ~150 million very thin tiny sacs (large surface area) One cell layer thick, surrounded by capillaries Diaphragm Increases and decreases volume of chest cavity Dome shaped, thin, muscular

Respiration and Gas Exchange the gases are exchanged due to differences in CONCENTRATION. O2 in inhaled air > O2 in blood of capillaries in lungs. CO2 in inhaled air < CO2 in blood of capillaries in lungs. So in external respiration, O2 diffuses from the alveoli to the capillaries and CO2 diffuses from the capillaries to the alveoli.

Mechanics of INSPIRATION (breathing in) Diaphragm CONTRACTS and FLATTENS (moves downwards) Rib muscles CONTRACT and move ribcage UPWARDS Result: Lung volume: INCREASED Pressure inside the lungs: DECREASED AIR MOVES IN

Mechanics of EXPIRATION (breathing out) Diaphragm RELAXES and RETURNS to DOME shape Rib muscles RELAX and move ribcage DOWNWARDS Result: Lung volume: DECREASED Pressure inside the lungs: INCREASES AIR MOVES OUT *Internal intercostals can pull ribs in further to force exhalation

Lung Capacities The full capacity of your lungs is not used up under normal conditions - consider yawning, or blowing out a candle, or exercising. A spirometer is used to measure lung capacities and produces a spirograph

Lung Capacities Tidal Volume: volume of air inhaled and exhaled in a normal breathing movement

Lung Capacities Inspiratory Reserve Volume: the additional volume of air that can be taken in, beyond a regular or tidal inhalation. Inspiratory Capacity: total volume of air that can be taken in (TV + IRV) IRV

Lung Capacities Expiratory Reserve Volume: the additional volume that can be forced out of lungs Vital Capacity: the total volume of gas that can be moved in or out of the lungs TV + IRV + ERV = VC IRV ERV

Lung Capacities Residual Volume: the amount of gas that remains in the lungs and passageways of the respiratory system even after full exhalation (prevents collapse, no value for gas exchange)