Normally, when you look at a
diagram of the human heart, you are looking at the heart dissected from its
ventral surface. So the right side of the heart will be facing your left and
heart is enveloped by a two-layered sac known as the pericardium. The
pericardium is attached to the breastbone, the diaphragm, and the
membranes of the thorax, thus together with the arteries and veins attached to
the heart, the pericardium help in holding the heart in a fixed position in the
body. Between the two pericardial membranes is the pericardial fluid which
reduce friction when the heart is beating. The pericardium also protects the
heart muscle, otherwise known as myocardium.
side of the heart is completely separated from the left side by means of a
muscular wall — the median septum, which runs down the middle of the heart.
The median septum is very important as it prevents the deoxygenated blood in the
right side from mixing with the oxygenated blood in the left side.
The heart is divided into four chambers. The two upper chambers are the atria (singular:
atrium) and the two lower chambers are the ventricles. Great blood vessels main
arteries and veins branches out from the heart, leading to and from all parts of
As you may
have noticed, the wall of the left ventricle is thicker than the wall of the
right ventricle. This is because the left ventricle exerts a greater pressure on
the heart muscles than the right ventricle does.
the heart are like doors that only open in one direction. They have important
roles to play.
©Copyright TQ Team
25896, 1999. The
Circulatory System- Online Learning.