Veins Flashcards
What are medium veins? Examples?
1-10 mm
Most named veins e.g. external jugular vein
What are large veins? Examples?
> 1cm
Vena cava, pulmonary vein
What are small veins?
0.1-1mm
What are venules?
10-100 um
T or F: Large veins tend to be companion vessels to large arteries
T (same down to the venule/arteriole level)
Describe the tunica intima in veins
Longitudinally oriented components
Endothelial layer
Small or absent subendothelial layer
ABSENT internal elastic membrane
Describe the tunica media in veins
Circularly oriented components
Smooth muscle cells
Collagen fibers
Describe the tunica adventitia in veins
Smooth muscle cells (longitudinal bundles in large veins)
Collagen fiber layer with fibroblast cells
Vasa vasorum and nerve fibers
T or F: The tunica media is considerably thinner in veins than in arteries
T
T or F: The internal elastic membrane is absent in veins and present in arteries
T (important distinction)
What is the most pronounced layer in large veins?
T. adventitia
What is the makeup of the tunica adventitia in large veins?
Large smooth muscle bundle, clusters of collagen fibers and extensive vasa vasorum
T or F: Some veins have an internal elastic membrane
T but not common
Compared to the artery, the vein has what type of lumen? Wall?
Wider and thinner
What is the pampiniform plexus?
Complex system of branching veins for the venous drainage of the testes