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The Respiratory System. Chapter 10, Page 334 – 351. What Is A Respiratory System?. The system of organs involved in the uptake and exchange of oxygen and carbon dioxide between and organism and its environment. Different organisms have different respiratory systems!.
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The Respiratory System Chapter 10, Page 334 – 351
What Is A Respiratory System? • The system of organs involved in the uptake and exchange of oxygen and carbon dioxide between and organism and its environment. • Different organisms have different respiratory systems!
Functions of Respiratory System 1. To maintain Homeostasis 2. To provide O2, and remove CO2, from cells = Gas Exchange 3. Contributes to our ability to talk
Requirements of Respiratory System 1. Big surface area for gas exchange to occur at the rate to meet organism’s need 2. A moist environment for gases to dissolve FISH GILLS INSIDE HUMAN LUNGS
Passage of Air Through Our Respiratory System Upper Respiratory Tract: pg 335 1. Nose, mouth 2. Nasal cavity
Upper Respiratory Tract Cont’d 5. Epiglottis: “flap” that stops food from entering trachea 6. Trachea: “windpipe”
Lower Respiratory Tract: • (inside thoracic cavity) • Bronchi (bronchus-singular) : • Two small passageways that branch off the trachea and enter lungs. • Bronchioles: • Fine tubes that branch from the bronchi. • Lined with cilia and mucous
Alveoli: pg 336/337 • Tiny sacs (in grape-like clusters) at end of bronchioles. • Site of gas exchange (via diffusion). • Pleura (pleuron-singular) • Flexible membrane around lung.
Don’t write:Alveoli clusters at end of bronchioles. Average human lung has 70 to 90 m2 alveoli surface area. That’s about the size of a tennis court!
Mechanics of breathing (pg 338) • Gases move from areas of high to low pressure. • What controls this pressure?? • Intercostal muscles:on ventral surface and ribcage • Diaphragm: muscle between thoracic and abdominal cavity
Inhalation • Intercostals and diaphragm contract. • Ribs expand • Diaphragm lowers • Vol.increase and air pressure lowers • Lungs expand, air moves in.
Expiration/Exhalation • Diaphragm and intercostals relax. • Ribs lower • Diaphragm rises • Vol. decreases, pressure increases. • Lungs shrink, air is forced out.
Gas Exchange(pg339) • Between air in alveoli and blood in capillaries
Lung Capacity (pg 340) • Tidal Volume: • vol. of air inhaled and exhaled in normal breathing • Inspiratory reserve volume: • additional vol. that can be inhaled after normal breath. • Expiratory reserve volume: • additional volume that can exhaled beyond normal breath.
Vital Capacity: total vol. of air that can move in/out of lungs tidal vol. inspiratory reserve vol. + expiratory reserve vol. vital capacity
Residual Vol: • air that remains in lungs and passageways after full exhalation. • can’t get rid of it • prevents lung collapse • Respiratory efficiency: • rate of oxygen transport to bloodstream from lungs.
Diseases: • Lung cancer: • Uncontrolled growth of abnormal lung cells. • Carcinoma: a malignant, spreading tumour. • Once tumour cells enter lymphatic system the cancer “spreads”
Non-Smoker vs. Smoker Black=from air pollution and second hand smoke Black=tar White=cancer
Causes of lung cancer : • Cigarette smoke: • 87% of lung cancers. • Carcinogens cause lung cells to become anaplastic(less differentiated and quick to multiply since carcinogens damage DNA) • Radon: • a radioactive colorless, ordorless gas. • from soil and radiotherapy • Air pollution
Amount and type of tar build up in lung per year of smoking 1 pack/day
Treatments for Lung cancer: • Surgery • Radiation: • high energy x-ray that kills cancer cells. • Chemotherapy: • medication that kills cancer cells by preventing mitosis and causing apoptosis (cell suicide). • Also kills normal cells: hair loss, nausea.
Diseases: • Pneumonia: • Inflamed alveoli fill with fluid. • lowers oxygen intake. • Types: • Lobar pneumonia: entire lobe • Bronchial pneumonia: patches of lung
Causes: • Bacterial: • streptococcus pneumoniae,causes lobar pneumonia • Viral: • Shorter durations • Parasitic: • Mycoplasma,hardest to fight off Treatments: • vaccines and antibiotics
Asthma: • Inflammation of airways due to irritants • bronchioles constrict due to muscle spasms • mucous build ups • Lowers oxygen intake.
Treatments • Avoid triggers ( smoke, dust, pets……) • Medications: • Broncho-dilators/puffers: reduce inflammation • Anti-inflammatory drugs: prevent attacks