8.
The inner, smooth epithelial layer of a blood vessel is called the intima. The
middle layer of smooth muscle tissue is called the media. The outer layer of FCT
9.
The three types of blood vessels are arteries, veins, and capillaries. The arteries
carry blood away from the chambers of the heart. The veins carry blood toward
the chambers of the heart. Capillaries have extremely thin walls so that
exchanges can take place between the blood and tissue cells. (para 9-6b)
10.
The heart chambers are the four cavities into which the heart is divided. The atria
are the upper two chambers of the heart. Each atrium has an ear-like projection
known as an auricle. The ventricles are the lower two chambers of the heart.
Between the two atria is a common wall known as the interatrial septum. Between
the two ventricles is a common wall known as the interventricular septum.
11.
The three layers in the walls of the heart chambers are the endocardium, the
myocardium, and the epicardium. The inner layer is a smooth epithelium. The
middle layer is made up of cardiac muscle tissue. The outer layer is another
12.
The atrial walls are relatively thin. The right ventricular wall is much thicker than
the atrial walls. The left ventricular wall is three to five times thicker than the right
13.
The valve between the atrium and ventricle of each side is the atrioventricular
(A-V) valve. The right A-V valve is known as the tricuspid valve. The left A-V
valve is known as the mitral valve. The fibrous cords attached to the underside of
the A-V valves are called chordae tendineae. They are attached to the inner walls
The valve at the base of the pulmonary trunk and the valve at the base of the
aortic arch are both semilunar valves, each with three cusps. They are often
14.
Extrinsic nervous control of the heart is exerted by nerves of the autonomic
nervous system. Speeding the heart up are the sympathetic cardiac nerves.
Slowing the heart down is the vagus parasympathetic nerve. (para 9-7b(1))
Intrinsic "nervous" control is built within the heart. It consists of the sinoatrial (S-A)
node, the atrioventricular (A-V) node, and the septal bundles. (para 9-7b(2))
For humoral control, there appears to be substances in the blood itself which have
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