MYTHS & MISCONCEPTIONS
MISCONCEPTION:
ALL arteries carry oxygenated blood; ALL veins carry deo-xygenated blood FACT: Human blood is red, ranging from bright red when oxygenated to dark red when not. It owes its colour to hemoglobin, a metalloprotein compound containing iron in the form of heme, to which oxygen binds. There exists a popular misconception that deoxygenated blood is blue and that blood only becomes red when it comes into contact with oxygen. Blood is never blue, but veins appear blue because light is diffused by skin. Moreover, the blood inside is dark red and exhibits poor light reflection. From a physiological perspective, veins and arteries appear similar when skin is removed and are seen directly. |
PEDAGOGY: DEBUNKING MISCONCEPTIONS
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MISCONCEPTION:
Blood travels in one continuous loop around the body FACT: The correct conception that lungs are involved in blood circulation, further that there is a double loop path, pulmonary and systemic. |
Starting with debunking the common misconceptions and then having a discussions around other misconceptions students may have is a good way to get students asking questions and thinking about the form and function of the circulatory system.
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