Blood vessels
|
Function
|
Artery (and arteriole)
|
Carry blood from the (1) heart to the tissues
|
(2) Vein (and
venule)
|
Return blood from the tissues to the heart
|
Capillary
|
n connect with the artery and the vein
n
site of (3) material exchange between the blood
and the tissue cells
|
Ø Differences
between arteries and veins: CE-2006-I-A-Q1, CE-2005-I-B-Q8a,
CE-2004-I-Q3
Artery
|
Vein
|
Direction of blood flow
|
Away from the heart
|
Towards the heart
|
Nature of blood carried
|
(4) oxygenated
/ deoxygenated blood
(except in the pulmonary artery and the umbilical arteries臍動脈)
|
(5) deoxygenated blood
(except in the pulmonary veins and the umbilical vein臍靜脈)
|
Wall
|
n Thicker
n with more muscular tissue which can
contract and relax:
è change the
size of lumen
è regulate the blood
flow
n with more elastic tissue
è the elastic (7) tissues help maintain
the blood flow
|
Thinner, with less (6) elastic tissues and muscular tissues
|
Lumen
|
Smaller
|
Larger (resistance to
blood flow is reduced)
|
Driving force for blood flow
|
Provided by the pumping action
of
the (8) heart
|
Provided by the contraction of
the
(9) skeletal
muscles that squeeze on the veins
|
Blood pressure
|
High, due to the
pumping action of the heart
|
Low (the pressure
drops after blood passing
through the (10)
capillaries)
|
Presence of valves
|
Not present (except in the
pulmonary
artery and the (11)
aorta
which have valves at their base)
|
Valves are present to prevent the
(12) backflow of blood
|
Location
|
Usually deep
inside the body, to avoid being damaged.
|
Relatively
close to the body surface
|
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