Unit 2 Topic 5 The Respiratory System

What is respiration?  Exchange of gases between the internal environment and the external environment  Need O 2 in (for cellular respiration)  Need CO 2 out (waste product) O2O2 C 6 H 12 O 6 CO 2 Cell ATP

Respiratory systems  General characteristics of respiratory systems: 1. Thin, moist surfaces 2. Large surface area: volume ratio  Mechanisms of gas exchange in animals: 1. Direct with the environment 2. Tracheae 3. Gills 4. Lungs

Lungs: Our system of gas exchange A B C D E E F G H I

Negative pressure breathing inhaleexhale

Sort of random video… How do you think this information relates to gas exchange? 78% nitrogen 21% oxygen 0.04% carbon dioxide

Alveoli

Moving gases into bloodstream  Step 1: Inhale to fill lungs with “fresh” air  O 2 passes from alveoli to blood by simple diffusion (high to low concentration)  CO 2 passes from blood to alveoli by simple diffusion (high to low concentration)  Step 2: Exhale to empty lungs. Capillaries carrying low O 2 / high CO 2 concentration blood back from body. Capillaries carrying high O 2 / low CO 2 concentration blood out to the body.

Red blood cells and hemoglobin Blood= 45% cells (red, white, platelets) 55% “plasma” (nutrients, water, vitamins, hormones, cellular waste, ions)

Respiratory System Special Topics

Chronic Respiratory Diseases OBJ 28

Common respiratory infections  Pneumonia  Bronchitis

Smoking and the lungs Cigarette smoke: carbon coated in 4,000 toxic chemicals  Benzene  Ammonia  Formaldehyde  Arsenic  Cyanide Smoking:  Causes cilia to stop moving (for 20 minutes)  Increases amount of mucus in the air passages (cilia no longer clearing mucus)  Kills immune cells on respiratory tract  Decreases the amount of oxygen carried by blood  Leads to tar build-up in your lungs  Second-hand smoke also contains many toxins

Lung Cancer  Tumors form in the lungs OBJ 28

Cystic Fibrosis  Genetic disorder that affects the structure of 1 protein.  Chloride ions protein pumps in cells of the trachea don’t work  Results in production of abnormally thick and sticky mucus  Mucus builds up in lungs and pancreas  People with this disorder live much shorter lives (now up to late 30s/early 40s, only a couple of decades ago, most died in childhood)

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