What is the atrio-ventricular septum made of?ACartilageBFibrous tissueCOsteocytesDMucous membraneAnswer: B. Fibrous tissue Read Explanation: The human heart is divided into four chambers- two atria and two ventricles. They pump blood to different parts of the body. The atrio-ventricular septum separates the atria and the ventricles. It is made of fibrous tissue. Read more in App