Explain the structure of the heart and lungs, including tissue types and cells.

I
will explain the structure of the human heart, including the tissues and cells, here.

The human heart is shaped roughly like a human fist and consists of four chambers: two
atria and two ventricles. The atria (plural; the singular term is atrium) are the chambers that
receive the blood, while the ventricles are the chambers that pump the blood in our body. The
two atria are the left and the right atria. Similarly, the ventricles are also classified as the
left and the right ventricles.

The right atrium receives the deoxygenated
blood from the body and passes it onto the right ventricle through the tricuspid valve. This
deoxygenated blood is passed to the lungs for reoxygenation and is received by the left atrium.
This blood is then passed to the left ventricle through the bicuspid valve and from there is
pumped to the rest of the body.

The primary type of tissues present in the
human heart is cardiac muscle tissues. These tissues contain a variety of cells, including the
fibroblasts, smooth muscle cells, and cardiomyocytes. It is interesting to note that the
movements in the cardiac muscle tissues are involuntary, which means that they cannot be
controlled by us, unlike the skeletal muscle tissues. The heart also contains the pacemaker
cells, which generate electrical impulses that tell the cardiac muscle cells to contract and
relax.

Hope this helps.