Question

J. Heart is made
up of
tissue​

Answer 1

Answer:

Explanation:The heart is made up of four different blood-filled areas, and each of these areas is called a chamber. There are two chambers on each side of the heart. One chamber is on the top and one chamber is on the bottom. The two chambers on top are called the atria.

Answer 2

Answer:

A thin outer leaning protect your surrounded of heart