Chapter

2

Vascular Biology, Structure and Function

2.1

the

2.1.1 The Circulatory System

The heart, the arterial

systems, the venous systems

and

the

microcirculatory systems, coupled with neuro-humoral influences form

the entire circulation. Each is an important functional complement that

the circulatory system cannot be effectively described by one part alone.

By virtue of the distributing vascular trees, oxygen, humoral agents, and

nutrients are transported to the vital parts of the body and the waste

products are removed. The heart provides the necessary energy.

In terms of the general structure components, Fig.

2.1.1

suffices to

provide an overview of the connectivity of the circulation.

2.1.2

The Heart

The heart in mammalian species has four chambers, the

ventricle, the

right ventricle,

and right atria. The left ventricle pumps blood into

the aorta and perfuse the systemic arterial system and the right ventricle

pumps into the main pulmonary trunk and perfuse the pulmonary arterial

tree.

The shape of the left ventricle is in-between conical and semi-

ellipsoidal with its narrow end forming the apex of the heart. These

shapes, as well as cylinder and sphere, have been used in ventricular

modeling. The left ventricular wall is about three times as thick as the

right ventricle, thus

is

able to develop a much higher pressure. The thick

interventricular septum, separating the left and right ventricles,

more