======Blood Flow and Artery Constriction======


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**Alternative titles:** Heart Trouble
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====Summary====                   
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====Procedure====  
  - Put on safety goggles and a lab coat.  
  - Have an assistant plug the ends of both tubes (one wide, one narrow).  
  - Fill a quart container with 1000 mL of water mixed with red dye.  
  - Connect the container to both the ½-inch and ¼-inch tubing using nylon barb adapters.  
  - Place the free ends of the tubes into two separate 1000 mL beakers.  
  - Ask students to predict how much liquid will flow from each tube.  
  - Have the assistant release both tubes at the same time and observe the water flow.  
  - Note that the larger tube allows significantly more water to flow, while the smaller tube fills its beaker much more slowly.



====Links==== 
📄 Heart Trouble (on page 4 of pdf) - Kirsten Johnson: [[https://www.unco.edu/nhs/science/pdf/demos/2007_NSTA_demos.pdf]]\\

====Variations====
  * Use multiple tubes of different diameters to compare a wider range of flow rates.  
  * Try changing the height of the container to model blood pressure changes.  
  * Add clamps to mimic partial blockage or stress-related narrowing of arteries.



====Safety Precautions====
  * Wear goggles to protect eyes from splashes.  
  * Wear a lab coat or apron to protect clothing from red dye stains.  
  * Clean up spills immediately to avoid staining and slipping hazards.




====Questions to Consider====
  * What would happen to the heart of a person who has constricted vessels? (The heart would have to work harder to pump blood, increasing risk of heart disease or failure.)  
  * What other systems in the body would this affect? (The brain, muscles, and organs may receive less oxygen and nutrients, leading to fatigue, dizziness, or organ damage.)  
  * How does this model help explain why high blood pressure is dangerous? (It shows how increased resistance in arteries forces the heart to pump harder, straining the cardiovascular system.)  
  * What lifestyle choices or medical conditions might cause arteries to narrow? (Plaque buildup from poor diet, smoking, stress, or conditions like atherosclerosis.)