Name the three layers or tunics of the blood vessel wall and what they are composed of:
1. Innermost
2. Middle
3. Outer

1. Tunica Intima, One layer endothelial cells supported by internal elastic lamina
2. Tunica Media, Smooth muscle and elastin tissue
3. Tunica Externa, Collagen and supported by external elastic lamina

In the following list of characteristics, put "A" for artery, "C" for capillary, and "V" for vein:
1.___ contain the lowest pressure
2.___ has thick tunica media
3.___ smallest of the blood vessels
4.___ largest lumen-- Blood reservoir
5.___ carries blood toward the heart
6.___ contain the highest pressure
7.___ thin tunica media
8.___ carries blood away from the heart
9.___ has only one tunic (intima)
10.___ site of exchange of nutrients

1. V
2. A
3. C
4. A
5. V
6. A
7. V
8. A
9. C
10.C

Name the three groups of arteries:
1.____________
2.____________
3.____________

1. Elastic Arteries
2. Muscular Arteries
3. Arteriole Arteries

____________ arteries have a thick tunica media with the greatest amount of elastin. They also experience the greastest pressure and the widest variation in pressure. the best example is the __________.

1. Elastic
2. Aorta

Compared to the arteries above, the muscular arteries have more smooth muscle but less___________. They deliver blood to specific organs. The __________ artery delivers blood to the kidney and would be an example of this type of artery.
Small changes in the diameter of these blood vessels greatly influence blood flow and blood _________. Stimulation of vasomotor fibers would cause (vasoconstriction or vasodilation) of the blood vessels.

1. Elastin
2. Renal
3. Pressue
4. Circle "Vasoconstriction"

The smallest arteries are called_________. The steepest drop in blood pressure occurs in these vessels, thus they offer the greastest _________ to flow.
an increase in blood flow through a feeder arteriole will (increase or decrease) blood flow through the capillary.

1. Arterioles
2. Resistance
3. Circle "Increase"

Capillaries:
The ___________ is a short vessel that directly connects the arteriole and venule. When blood flows through this vessel, there is no exchange of materials.
The ____________ controls blood flow into the true capillaries. Exchange of materials takes place from these capillaries. Compared to blood pressure in the arteries, blood pressure (high or low) in the capillaries.

1. Shunt
2. Pre-capillary sphincter
3. Circle "low"

Venules:
THe smallest venules are formed when capillaries unite. They consist maily of ____________ around which a few fibroblasts congragate. Blood flow continues to ( increase or decrease) in the venules.

1. Endothelium
2. Circle "decrease"

Veins:
Veins have three distinct tunics, with the tunica ____________ being the haviest. Veins have __________ walls and __________ lumens than arteries.

1. Externa
2. Thinner
3. Longer

Since pressure is lower in the veins, special adaptations are necessary to return blood to the heart. these three structural adaptations are: 1._______________. Here, ________________ prevent backflow as blood travels toward the heart.
2._______________. Here, contracting ___________ muscles press against veins forcing blood throught #1 above.
3._______________. During inspiration, pressure (increases or decreases) in the thoracic cavity and (increases or decresaes) in the abdominal cavity. This results in an upward "sucking" effect that pulls blood towards the heart.

1. Venous valve. One-way
2. Muscle Pump. Skeletal
3. Respiratory Pump, Circle decreases, Circle increases.