270 likes | 363 Vues
Discover the importance of the respiratory system, from the cellular to organism level. Learn about its organs, gas exchange process, mechanics of breathing, control mechanisms, lung capacities, and common problems like asthma, lung cancer, and emphysema. Explore how this vital system functions and how to maintain respiratory health.
E N D
The Respiratory System Inhale … Exhale …
How important is the Respiratory System? • How long can you hold your breath?
2 different levels • Cellular, or internal • Organism level
Why Breath? • Respiratory System is a group of organs working together to bring about the exchange of oxygen and carbon dioxide with the environment
Respiratory System consists of: • Nose • Nasal cavity • Pharynx • Larynx • Trachea • Smaller conducting passageways • Lungs
air is about 21% Oxygen; 78% Nitrogen; 1% Carbon dioxide, water vapor, argon, and other trace gasses (neon, helium, krypton, hydrogen, and ozone are a few)
Air enters through the nose or mouth • Into the nasal cavity – warms and moistens air • Enters pharynx – back of throat – serves as passageway for food and air • Trachea – windpipe – leads to lungs
Direct connection to outside – must filter dust, dirt, smoke, bacteria and other contaminants • When air goes through the mouth, it doesn’t get filtered as much as when it goes through the nose and nasal cavities • Lined with mucous secretions and hair
Top of trachea is Larynx • Made of cartilage (largest is the Adam’s Apple) • Also known as Voice box • Inside is two folds of tissue – the vocal cords
Trachea • C – shaped rings of cartilage • Protect the trachea • Make it flexible • Keep it from collapsing
Cells that line the trachea • produce mucus • Lined with cilia • Particles are trapped in the mucus and carried to upper trachea – swept down into digestive system • Smoke = Sabotage to system • Cilia stop working after a while • When this happens, particles get lodged in the trachea – SMOKER’S COUGH
Trachea divides to bronchi • Bronchi divide into smaller and smaller passageways and lose the cartilage rings to become bronchioles • Bronchioles divide further and further until they end in small clusters of hollow air sacs – alveoli • Gas exchange occurs in alveoli
Mechanics of Breathing • Inhalation and Exhalation • Air pulled into the lungs and air pushed out of the lungs • 10 – 15 X in a minute • Diaphragm – large flat muscle along bottom of rib cage and Intercostal (between ribs) muscles
Blood enters capillaries around the alveoli • Carbon dioxide rich blood enters, Carbon dioxide diffuses out, Oxygen diffuses in – concentrations are unequal across the alveolar membrane of gasses
Phospholipids and protein produce a “surfactant” to coat the inside of the alveolus • Keeps it open and makes it easier to exchange gasses
Hemoglobin – Found in red blood cells – iron containing compound – makes red blood cells red • Without Hemoglobin, blood would only be able to carry about 2% of the oxygen needed by the body.
Control of Respiratory System • Breathing is involuntary • What makes you breath?
How does the nervous system control breathing? • Sensory neurons check levels of gasses in your blood. • One set in carotid arteries in the neck • Other set in the aorta • These are sensitive to levels of gasses in the blood – especially Carbon Dioxide
LUNG CAPACITIES • Total Lung Volume – about 6 L • Residual Volume – Following a normal exhalation, what is left (about 2 ½ L) • Tidal Volume – Volume of air inspired or expired during a normal (at rest) breath (1/2 L per cycle) • Inspiratory Reserve – additional air that can be breathed after a normal inspiration (4 ½ L) • Vital Capacity – total volume of breathable air
Problems • Hypoxia – High CO2 levels in the blood – provides greatest stimulus to breath • Influenced by oxygen partial pressure, increased gas density, and emotional states • Asphyxia – existence of both hypoxia (oxygen shortage) and Carbon Dioxide excess • Suffocation – stoppage of breathing for any cause resulting in asphyxiation • Strangulation – stoppage of breathing due to obstruction
Asthma • Restriction of airways due to inflammation • May cause • Shortness of breath • Wheezing • Coughing • Can be triggered by • Cold • Allergies – dust, pet hair, smoke, pollen, etc… • Exercise
Asthma • Medicines include • Long acting to prevent attacks • Short acting during attacks (bronchodilators)
Emphysema • COPD – Chronic Obstructive Pulmonary Disease • Lung tissue destroyed – cannot function fully • Irreversible condition • Steroids and other drugs • May need Oxygen permanently