a.Wall of arteries and veins have same three layers
i.Innermost: tunica intima
ii.Tunica media
iii.Tunica adventitia
Explain the tunica intima
innermost
endothelium (simple squamous)
Explain the tunica media
1.Smooth muscle and elastic connective tissue
a.Dense connective tissue that has a lot of elaborate fibers in it
2.Thickest layer in the wall of an artery because that’s the layer responsible for vasoconstriction and vasodilation of that vessel (opening and closing of the lumen)
Tunica adventitia
1.Connective tissue layer that anchors nerves and other blood vessels to that vessel and anchors that vessel to that organ
True or False: Veins have same three layers and same composition in those layers with no differences
false
with some differences
What is the first difference of the veins in the tunica intima?
i.In tunica intima of a vein, there are valves jutting from that layer
1.Simple flaps that jut out into the lumen
2.Prevent backflow
What is a second difference between veins and arteries in tunica media?
it is not very thick in comparison to the comparable artery
1.Lumens of veins are larger because wall is thinner
What does comparable mean?
a.If you’re looking at the ulnar artery, look at the ulnar vein
If you’re looking at the vena cava, look at the aorta
Why is the tunica media much thinner in the veins than the artery?
a.Arteries are pumping under much harder pressure because its from the heart that they go to arteriesà capillary bed (has a large cross-sectional area, decreasing pressure, causing veins to operate under much lower pressure than arteries)
WHat do the veins get help from?
a.Veins get help from the skeletal muscle that surrounds them
i.As the muscles contract, they help milk the blood; they help contract those vessels
Capilaries: sequence?
Where are the larger arteries found?
