Lecture 5- Structure and Function of Blood Vessels Flashcards
what supply do all tissues have
arterial supply
what drainage do all tissues have
venous drainage
3 core functions of blood vessels
-resilient
-flexible
-always remain open
what is the standard blood vessel structure
tunica intima->tunica media-> tunica adventitia/ externa
what epithelium is found in the tunica intima?
simple squamous epithelium
endothelium
epithelium that lines blood vessels
what do the epithelial cells in the tunica intima have
basal lamina (extracellular matrix of epithelial cells)
what connective tissue is found in the tunica intima
subendothelial connective tissue
what is found in the loose connective tissue of the tunica media
smooth muscle fibres
which fibres may the tunica media contain
elastic fibres
structure of the tunica externa/adventia
Connective tissue
Merges with surrounding connective tissue
May contain vaso vasorum (vessles of the vessels)
why do arteries have thick walls
blood is under high pressure
what do arteries resemble and what do veins resemble
arteries- garden hoses (smaller lumen)
veins- fire hoses (larger lumen)
why do valves have thin walls
as blood travels under low pressure
which is more resilient: arteries or veins?
arteries
what are the 3 types of arteries
elastic (conducting)
muscular (distributing)
arterioles (resistance vessels)
examples of elastic (conducting) arteries
aorta, brachiocephalic and common carotid
diameter of elastic (conducting arteries )
up to 2.5 cm
function of elastic (conducting arteries)
withstand changes in pressure during the cardiac cycle and ensure continuous blood flow
structural adaptations of elastic ( conducting arteries)
thick tunica media with many elastic fibers and few smooth muscle cells
examples of muscular (distributing) arteries
brachial and femoral arteries
diameter of muscular (distributing) arteries
0.5 mm – 0.4 cm
function of muscular (distributing) arteries
-Distribute blood to muscles and organs
-Capable of vasodilation and vasoconstriction
in order to control the rate of blood flow to
suit the needs of the organ
-e.g contracting muscles during exercise- dilate blood vessels
structural adaptations of muscular (distributing) arteries
smooth muscle cells in tunica media
distinct internal (IEL) & external elastic laminae (EEL)
thick tunica externa
diameter of arterioles (resistance vessels)
</= 30 um
function of arterioles (resistance vessels)
-Capable of vasoconstriction &
vasodilation
-Control blood flow to organs
-Involved in blood pressure control