3-5.
BLOOD FLOW
In order to summarize how blood flows in the body, let's take a trip through the
body's circulatory system (see figure 3-3). We will enter the system at the inferior vena
cava.
Direction of blood flow
A.
Superior vena cava
B.
Inferior vena cava
C.
Right atrium
D.
Tricuspid valve
E.
Right ventricle
F.
Pulmonary valve
G.
Pulmonary arteries
H.
Lungs
I.
Pulmonary veins
J.
Left ventricle
K.
Mitral valve
L.
Left ventricle
N.
Aorta
O
Interventricular septum
Figure 3-3. Blood flow to and from the heart. (Not drawn to scale; front view).
a. Vena Cava. There are two major blood veins that empty into the right atrium.
The inferior vena cava carries oxygen-poor blood from the lower trunk and legs. The
superior vena cava drains blood from the head and upper chest.
MD0571
3-6