What are the 2 main types of arteries
- Elastic (conducting) arteries
- Muscular (distributing) arteries
there is no clear demarcation between these two they gradually transition from one to the other
What are the characteristics of the elastic arteries (conducting)
- Found closest to the heart and the common iliacs because they are able to withstand high pressures
- They act as a pressure reservoir, to propel blood forward while ventricles are in diastole, using elastic recoil
- highest percentage of elastic fibers, highly arranged
- large diameter
What are the characteristics of the muscular (distributing) arteries
- Arteries whose tunica media contains a large amount of smooth muscle and less elastic fiber when compared to elastic/conductive arteries
- greater vasoconstriction and vasodilation which helps adjust rate of blood flow and push blood forward
Define anastomoses
the union of 2 or more vessels in the same tissue (ie veins to veins or arteries to arteries)
Define collateral circulation
when a blockage or slow flow occurs in small vessels anastomoses can occur in that vessel “bypassing” the occlusion or slow flow
What are the characteristics of arterioles
- also known as resistance vessels
- Microscopic vessels that are the regulator of blood flow to capillaries
- helps regulate overall blood pressure, when these constrict you get greater BP
What is vascular tone and what is it caused by
it is the partial contraction at all times of the tunica media of arterioles
it is caused by the sympathetic nervous system
What are Metartioles
Vessels that connect arterioles to capillary networks
-characteristics of both arterioles and capillaries
What is a pre-capillary sphincter
a single smooth muscle cell that acts at metarteriole capillary junction to tightly control flow into the capillary
True or False pre-capillary sphincters are open most of the time
False, they are closed. If they were open there would be limited blood in our other vessels.
Open to feed tissue w/ O2 and nutrients and remove waste
What is the function of a thoroughfare channel
a central channel that allows blood to flow from the metarteriole to the post capillary venule when precapillary sphincters are closed.
Describe an arterial laceration
spurting blood with pressure of the heart beat
