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Respiration and Circulation — BIOLOGY STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYRespiration and Circulation3 Marks
Question
Describe the structure of the heart wall.
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Answer

  1. The heart wall is composed of three layers, viz. outer epicardium, middle myocardium and inner endocardium.
  2. Epicardium is composed of single layer of mesothelium having flat epithelial cells.
  3. Myocardium is composed of cardiac muscle fibres. These muscle fibres perform the function of systole and diastole by showing contraction and relaxation of muscle wall of the heart.
  4. Endocardium is composed of single layer of flat epithelial cells called endothelium.

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