Arterial System

Question 1

What are the 2 main types of arteries

Answer 1

1. Elastic (conducting) arteries
2. Muscular (distributing) arteries

there is no clear demarcation between these two they gradually transition from one to the other

Question 2

What are the characteristics of the elastic arteries (conducting)

Answer 2

• 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

Question 3

What are the characteristics of the muscular (distributing) arteries

Answer 3

• 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

Question 4

Define anastomoses

Answer 4

the union of 2 or more vessels in the same tissue (ie veins to veins or arteries to arteries)

Question 5

Define collateral circulation

Answer 5

when a blockage or slow flow occurs in small vessels anastomoses can occur in that vessel “bypassing” the occlusion or slow flow

Question 6

What are the characteristics of arterioles

Answer 6

• 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

Question 7

What is vascular tone and what is it caused by

Answer 7

it is the partial contraction at all times of the tunica media of arterioles

it is caused by the sympathetic nervous system

Question 8

What are Metartioles

Answer 8

Vessels that connect arterioles to capillary networks

-characteristics of both arterioles and capillaries

Question 9

What is a pre-capillary sphincter

Answer 9

a single smooth muscle cell that acts at metarteriole capillary junction to tightly control flow into the capillary

Question 10

True or False pre-capillary sphincters are open most of the time

Answer 10

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

Question 11

What is the function of a thoroughfare channel

Answer 11

a central channel that allows blood to flow from the metarteriole to the post capillary venule when precapillary sphincters are closed.

Question 12

Describe an arterial laceration

Answer 12

spurting blood with pressure of the heart beat