Cardiovascular pressure and capacitance Flashcards
What are the 3 layers of the walls of blood vessels?
Tunica interna
Tunica Media
Tunica externa
What does tunica interna have?
epithelial inner lining
endothelium, BM (collagen fibres) Internal elastic lamina (elastic fibres)
What does tunica media have?
Elastic fibres and circular smooth muscle cells, arteries present
What does tunica adventitia have?
Elastic and collagen fibres
support and vaso vasorum
How many types of blood vessels are there?
5
What are the 2 types of arteries?
Elastic conducting
Muscular distributing
What do large arteries do?
propel blood while ventricles are relaxing - pressure reservoir
What do medium size arteries do?
Transport blood over long distances with little drop in BP
What are 3 layers of arteries?
Tunica interna - squamous epithelium BM Lamina
Thick tunica media smooth muscle
Tunica externa
Describe Arterioles?
Thin tunica interna fenestrated elastic lamin dissappears at terminal end
tunica media - 2 layers smooth circle muscle
tunica externa - elastic and collagen
smaller than arteri
Why are Arterioles important?
By vasoconstriction and vasodilation influence peripheral resistance and modify blood flow from arteries to capillaries - Resistance vessels
What is the terminal end of the arteriole?
Metarteriole - tunica interna surrounded by loose smooth mc
What is at the metarteriole capillary junction?
distalmost muscle cells from precapillary spincter monitor blood flow to capillar
What is at the distal end of a vessel?
Thoroughfare channe; - provides direct route for blood from arteriole to venule bypassing capillaries
What is Vasomotion?
Intermittent blood flow due to alternating contraction and relaxation of smc of metarterioles