The innermost layer of a blood vessel made up of a single layer of squamous endothelial cells is the __________ ___________.
2.
_____________ cells line the inner surface of the entire circulatory system.
3.
The ___________ ____________ is the middle layer of a blood vessel and is composed of smooth muscle and a thin layer of elastic tissue. It is controlled by the autonomic nervous system.
4.
The smooth muscle middle layer of blood vessels is much thicker in...
A. 
Arteries
B. 
Veins
5.
The __________ ___________ or ___________ is the outer layer of blood vessels and is composed of connective tissue that functions to reinforce and support the vessel.
6.
The thick muscular middle layer in _________ allows them to resist large ___________ generated from the hearts pumping action.
7.
The thin muscular layer in __________ allows them to collapse and also hold more blood (approx 70-80%).
8.
Movement of blood back to the heart is aid by what 3 factors?
9.
Valves in veins are most commonly found in the ______________.
10.
There are valves in the IVC, portal veins, and the pulmonary veins
A. 
True
B. 
False
11.
Capillary walls are made up of only one layer, the __________ ___________.
12.
The primary force by which gases are exchanged between the capillary walls and cells in the body is called _____________.
13.
A secondary force that moves water and dissolved materials from the capillaries into the tissue fluid is the ___________ of blood.
14.
A force that moves fluid into the capillaries is called __________ ___________.
15.
An increase in the diameter of a blood vessel and therefore allowing more blood to an area is called ______________.
16.
A decrease in diameter of a blood vessel, causing a decrease of blood flow is called __________________.
17.
The blood flow into individual capillaries is regulated by smooth muscles that encircle the entrance to the capillary called a ______________ _______________.
18.
Precapillary sphincters are only on the venous side of cells.