blood vessels and arteries Flashcards
name the 3 layers most blood vessels have and what they are made of
tunica intima (internal), endothelium tunica media (middle), smooth muscle and elastic fibres tunica adventitia (external), connective tissue
what is a neurovascular bundle
a group consisting of nerve, artery and vein closely together
properties of arteries
carry oxygenated blood usually located deeper than veins round lumen pulsatile high pressure
describe arterioles
name of arteries when they become smaller, they have smooth muscle in walls which can contract
what is the sympathetic tone of arterioles
background low level of contraction of arterioles
what does smooth muscle in arteriole walls allow
vasodilation and constriction
what is anastomoses
this is when arteries connect with no intervening capillary network
why does anastomoses occur
to allow another route of blood supply past arterial blockage (eg at bent joints)
what is the name given to the alternate routes at anastomoses
collateral
what is an end artery
it is the only arterial blood supply to a certain area of the body
what does an occlusion of an end artery lead to
an infarction of the territory the end artery was supplying
what is meant by the term infarction
irreversible cell death caused by lack of oxygen (hypoxia), caused by loss of arterial blood supply (oxygenated blood)
