Aneurysms

Question 1

Arterial vs venous system?

Answer 1

venous- low resistance vessels which take deoxygenated blood back to the heart

arterial- carries oxygenated blood from the heart to perfuse all the organs in the body. Much higher pressure

Question 2

What are the three main layers to the arterial wall?

Answer 2

tunica intima- endothelial cells which are in direct contact with blood flowing in lumen

tunica media - muscular layer made up of smooth muscle cells and connective tissue

tunica externa (adventita)- made up largely of connective tissues and the tiny blood vessels which supply walls of larger arteries also run in this layer.

Question 3

What is an aneurysm?

Answer 3

increase in diameter of an artery >1.5 times normal

AND

involving all layers of the arterial wall

Question 4

True vs false vs dissection aneurysm?

Answer 4

TRUE- all layers of arterial wall
(fusiform and saccular)

FALSE- hole in the wall of an artery through which blood escapes and is then contained by the surrounding tissues. Sometimes bounded by adventitia but more often a thin wall is developed from the fibrin/ platelet cross links-which form as part of the clotting cascade.

DISSECTION- tear in the intima-which allows blood to track between the layers of the arterial wall

Question 5

What are the arteries most affected by true aneurysms?

Answer 5

aorta (ascending, descending and abdominal), iliac arteries and the popliteal arteries.

Question 6

Less common locations of aneurysms?

Answer 6

aneurysms of visceral arteries (splenic artery and cerebral arteries)

Question 7

risk factors for aneurysms?

Answer 7

increasing age
male sex
genetics (connective tissue disorders)

Question 8

Why is diabetes protective for aneurysms?

Answer 8

actions on components like metalloproteins in vessel wall- resulting in stiffer, more rigid arterial walls