The Respiratory System Functions of the respiratory system: -Brings oxygen into the body and into the bloodstream -Removes carbon dioxide and water from the bloodstream and out of the body HINT: O2-needed for cellular respiration CO2/H2O-waste from cellular respiration

The main function of the respiratory system is therefore: GAS EXCHANGE!!! (for and from cellular respiration!)

The Respiratory System Where does the waste Carbon Dioxide and Water come from? -Your body uses oxygen and digested food (glucose) during cellular respiration and converts it to cell energy (ATP). Waste products of cellular respiration include carbon dioxide, which is a poison to your body, and excess water. You must get rid of it! – this is the job of your respiratory system

Organs of the Respiratory System Mouth Nasal passage Trachea Bronchioles Alveoli (air sacs at end of bronchioles) Diaphragm Lung Bronchi

The Respiratory System THE NOSE - Air is inhaled and exhaled through nostrils - Has hair (cilia) and mucus to filter out dirt/dust and warms and moistens the air - When you swallow the mucus, it goes into your stomach (digestive system) where you can digest and break down the dirt/dust/bacteria

The Respiratory System THE PHARYNX - AKA the throat - Shared with food passage - Epiglottis – flap; covers the top of the larynx and trachea, prevents food from entering trachea when you swallow (food goes to esophagus/air goes to trachea)

The Respiratory System THE LARYNX AKA the voice box Contains the vocal cords that vibrate when air passes along them to allow for sound. When the vibrations are modified by the tongue, palate, and lips, speech can be accomplished. Made primarily of muscles and cartilage

Side View of Upper Respiratory System

The Respiratory System THE TRACHEA - AKA the windpipe - Tube with cartilage rings- prevent the tube from collapsing (so it’s always open to breathe) - Has cilia and mucus, which sweep dirt/dust/bacteria UP to the pharynx so they can be swallowed into the stomach

The Respiratory System THE BRONCHI The trachea branches into 2 bronchi. One goes into each lung. The bronchi are the beginning of the lungs

The Respiratory System THE LUNGS - Inside the lungs, the bronchi divide into smaller and smaller tubes called bronchioles - At the ends of the bronchioles are alveoli, small air sacs where gases are exchanged. - This is where the circulatory system and the respiratory system meet. - The lungs are spongy because they are composed of thousands of these microscopic air sacs (alveoli)

The Respiratory System Where does gas exchange occur? - The ALVEOLI !!!! (they are surrounded by capillaries) How does gas exchange occur? -Process of Diffusion!!! Oxygen diffuses from the alveoli into the capillaries Carbon Dioxide and Water diffuse out of the capillaries into the alveoli Gas exchange animation Gas exchange animation #2

The Respiratory System How does air get into and out of your lungs? YOUR DIAPHRAGM! (a muscle) Which causes changes in air pressure diaphragm animation 3-D diaphragm animation

The main function of the respiratory system is: GAS EXCHANGE!!! (for and from cellular respiration!)