The Respiratory System Unit Three The Respiratory System

Learning Goal To take a closer look at parts of human respiratory system To learn more about the function of the respiratory system and gas exchange

Introduction Most of the cells in our bodies need a continual supply of Oxygen (O2) to carry out cellular respiration This process releases energy from glucose inside cells and produces Carbon Dioxide (CO2) as a waste product The left over chemical energy is used for the cell to carry out activities (cellular respiration – Gr. 12)

Introduction The structure of the respiratory system can be divided into2 main groups: The Upper Respiratory Tract The Lower Respiratory Tract

The Upper Respiratory Tract Air enters through the nose and mouth into the nasal cavity The NASAL CAVITY is lines with nose hairs and mucus to catch dust, bacteria, and other particles that were inhales with the air but are bad for the body

The Upper Respiratory Tract Air then travels into the PHARYNX (throat) Both inhaled air and food pass through the pharynx from the nasal and oral cavity From here air passes into the LARYNX (vocal cords)

The Upper Respiratory Tract A muscular tissue called the epiglottis works like a swing door opening on purpose for air to enter into the larynx and keeping food out, and vice versa, from food entering the esophagus and not into the larynx

The Upper Respiratory Tract From the larynx air flows into a tube called the TRACHEA (windpipe) The trachea is lined with cilia hairs and mucus to trap pollutants and other particles that made it past the nasal cavity when breathed in

The Lower Respiratory Tract Includes the lungs, bronchi, bronchioles, and alveoli Air continues to flow from the trachea down towards the lungs Inside the lungs are two branching tubes called BRONCHI

The Lower Respiratory Tract These bronchi then also are broken down into a smaller branches of smaller tubes called BRONCHIOLES Each lobe has its own amount of bronchioles This is beneficial in case one lobe gets injured – the other can still function and supply air to the tissues of the lungs

The Lower Respiratory Tract The smallest bronchioles end at a cluster of tiny air pockets called ALVEOLI Here O2 from the air we breathe in enters the alveoli and diffuses into the capillaries around them at the same time CO2 in the blood diffuses into the air in the alveoli * Remember diffusion = movement of a particle from a HIGHT concentrated area to a LOW concentrated area*

Review of Anatomy http://www.neok12.com/video/Respiratory-System/zX486a4000437c7b7b454e6b.htm (1:45) http://www.neok12.com/video/Respiratory-System/zX666d026275504f79626206.htm (start @ 2:30)

Introduction – Terms Respiratory System – is the group of organs that provide living things with oxygen from outside the body and disposes of waste products like CO2 Respiration – all the processes involved in bringing O2 into the body, making it available to each cell, and eliminating CO2 as waste

Respiration & Gas Exchange There are Four Stages in human respiration, where each stage has specialized structures to help it: Breathing External Respiration Internal Respiration Cellular Respiration

Respiration & Gas Exchange Stage 1 – Breathing Involves Inhalation (breathing in) and Expiration (breathing out) Inhalation – moves air from outside the body into the lungs inside the body Expiration – moves air from the lungs back to the outside of the body

Respiration & Gas Exchange

Respiration & Gas Exchange The inhaled air that enters the alveoli have a greater [ ] of O2 than CO2 The blood that circulates in the capillaries surrounding the alveoli has a greater [ ] of CO2 than O2 The differences in these concentration make a Concentration Gradient that helps gas exchange happen (step 2)

Respiration & Gas Exchange Step 2 – External Respiration Here, CO2 and O2 is exchanged between the inside of the lungs and the blood This stage is VERY IMPORTANT to our existence via the Gas Exchange Process Is the Delivery of O2 from the lungs to the blood Is the Elimination of CO2 from the blood to the lungs

Respiration & Gas Exchange In the lungs, oxygen diffuses from air in the alveoli into blood in the capillaries At the same time, carbon dioxide diffuses from the blood into the air in the alveoli The carbon dioxide leaves the lungs and exits through your mouth as you breathe out

Understanding Gas Exchange We see that the thin walls of the alveoli and the capillaries allow gases to diffuse through their cell membrane easily

Respiration & Gas Exchange

Animation http://www.aboutkidshealth.ca/en/howthebodyworks/introductiontotherespiratorysystem/pages/gasexchange.aspx

Understanding Gas Exchange

Understanding Gas Exchange As you can see, the air that enters the alveoli AFTER inhalation has a higher [ ] of O2 than the blood in the capillaries next to the lungs

Understanding Gas Exchange Thus, oxygen diffuses out of the alveoli into the blood in the capillaries

Understanding Gas Exchange The blood in the capillaries has a HIGHER concentration of CO2 than the air in the alveoli This is because CO2 is a waste produce of cellular respiration (step #4) and is brought up to the lungs from other cells in the body to be exhaled out

Understanding Gas Exchange Therefore, the body gets rid of CO2 (waste product) by having it move out from the capillaries and into the alveoli The CO2 is then exhaled out into the air and out of the body as NEW and FRESH O2 is breathed in and the cycle continues

Understanding Gas Exchange The reason why CO2 is able to move out of the capillaries and into the alveoli to be exhaled out And the reason why O2 is able to move from the alveoli and into the capillaries with fresh O2 for cells Is because of DIFFUSION – The movement of a substance from a High concentration to a Low concentration

Understanding Gas Exchange Where: There is a high [ ] of CO2 in capillaries and moves to the low [ ] area of the alveoli There is a high [ ] of O2 in the Alveoli from being breathed in and moves to the low [ ] of the capillaries in the blood

Respiration & Gas Exchange Step 3 – Internal Respiration Is the exchange of O2 and CO2 between the blood and the body’s tissues

Respiration & Gas Exchange Stage #4 – Cellular Respiration Is a bunch of reactions that work to make energy inside of cells where they: USE OXYGEN RELEASE CARBON DIOXIDE (waste)

Checking for Understanding What’s the difference between “Breathing” and “Respiration”? Answer: Respiratory refers to the chemical reaction inside cells. Breathing refers to the movement of air into and out of the lungs.

Activity!

Review http://www.dnatube.com/video/6094/Gas-Exchange-in-the-Lungs http://highered.mheducation.com/sites/0072495855/student_view0/chapter25/animation__gas_exchange_during_respiration.html

Understanding Gas Exchange

How do these gases move around in the body? During respiration, both oxygen (O2) and carbon dioxide (CO2) are transported via the bloodstream 99% of O2 that reaches cells is carried by Hemoglobin (Hb) Is a protein in RBC that is attracted to O2

How do these gases move around in the body? When CO2 leaves tissue cells and diffuses into the capillaries, it enters the RBC 23% of CO2 is carried in the blood by Hemoglobin The other 77% is in the blood as a dissolved gas When CO2 reaches the lungs, it diffuses into the air in the alveoli and is exhaled

How do these gases move around in the body?