Blood, the heart, circulation and respiration

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Question 59
Easy

Figure 1 shows a longitudinal section through a vein from a human limb.

Diagram showing a longitudinal section of a vein. Inside the blood vessel, there are two thin folding flaps of tissue labeled 'Structure Z' that meet in the middle to block downward flow but open upward to allow blood to flow towards the heart.

State the function of structure Z.

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Blood, the heart, circulation and respiration Questions

  1. GCSE
  2. /Biology
  3. /Blood, the heart, circulation and respiration