The Respiratory System Mr. Glatt 14-15

The Respiratory System

Function of the Respiratory System To bring about the exchange of oxygen and carbon dioxide between our blood and the air Oxygen in Carbon dioxide out Why is this important? Cells need oxygen to complete cellular respiration Glucose + Oxygent  Cabon Dioxide + Water + ATP (Energy) Carbon dioxide produced in this process becomes toxic to the body if it is not removed

Structures Nose and Nasal Cavity Provides a passageway for air to enter the body during respiration Air is filtered, moistened and warmed as it passes through these structures

Structures Pharynx Passage from the back of the mouth and nasal cavity that leads to the trachea & larynx Commonly known as the throat!

Structures Trachea The trachea is the tube that provides a passageway for air from the pharynx (throat) to the lungs Commonly known as the windpipe At the top of the trachea is a flap of tissue called the epiglottis The epiglottis closes off the trachea when we swallow The larynx or voicebox is also located at the top of the trachea It contains vocal cords

Structures Bronchii The bronchii are the two large airways that branch out from the trachea and enter the right and left lung. Each large bronchus branches out into smaller and smaller bronchii

Structures Bronchioles & Alveoli Bronchioles are the smallest passageways in the lungs. Each bronchiole leads into a clump of alveoli Alveoli are tiny air sacs that are clumped together like bunches of grapes Alveoli are surrounded by capillaries (thin walled blood vessels) Alveoli have very thin walls This is where oxygen and carbon dioxide are exchanged between the lungs and the blood

Gas Exchange Inhaled Air Exhaled Air 21 percent OXYGEN gas .04 percent CARBON DIOXIDE gas Exhaled Air 15 percent OXYGEN gas 4 percent CARBON DIOXIDE gas

How Breathing Works At the bottom of the chest cavity is a muscle called the diaphragm When the diaphragm contracts it causes the chest to expand When the chest expands a vacuum is created Low pressure air inside lungs Higher pressure outside lungs Air then rushes into lungs due to pressure difference When diaphragm relaxes chest gets smaller and air is forced out due to increased pressure inside chest

What Regulates Breathing Rate? Breathing rate is under autonomic control although we have the ability to consciously control our breathing rate The medulla oblongata is a specialized portion of the brain that regulates or breathing rate Measures and monitors carbon dioxide levels in the blood As carbon dioxide levels increase the medulla oblongata sends impulses to the diaphragm to contract more quickly causing breathing rate to increase