Blood Vessels
Blood Vessels
 Learning Objectives:
• Compare and understand
the difference in the
structure and function of
• Arteries
• Veins
• Capillaries
Arteries carry blood away from the heart.
the elastic fibres allow the
artery to stretch under
pressure
thick muscle and
elastic fibres
the thick muscle can
contract to push the
blood along.
1
2
3
Veins carry blood towards the heart
veins have valves which
act to stop the blood
from going in the wrong
direction.
thin muscle and
elastic fibres
body muscles surround the veins so
that when they contract to move the
body, they also squeeze the veins and
push the blood along the vessel.
Varicose Veins
 Some blood flows
backwards
 The walls
overstretch
Artery & Vein Compared
Capillaries link Arteries with Veins
they exchange materials
between the blood and other
body cells.
the wall of a capillary
is only one cell thick
The exchange of materials
between the blood and the body
can only occur through
capillaries.
A collection of capillaries is known as a capillary bed
artery
vein
capillaries
body cell
cell
endothelium
(one cell thick)
lumen
SUMMARY
copy and complete the following;
away from the heart. The walls of an artery are made
Arteries take blood ______
muscular walls and elastic fibres. Veins carry blood ________
towards
up of thick _________
the heart and also have valves. Thecapillaries
_________ link arteries and veins, and
have a one cell thick wall. Blood is made up of four main thingsplasma
______, the
liquid part of the blood; Red Blood Cells to carry oxygen
______; White Blood cells
platelets to help blood clot.
to protect the body from disease and _________
Task
Draw and complete a table to compare structure and
function of
arteries, veins and capillaries.
Artery
Function
Wall
Lumen
Pressure
Valves
Veins
Capillary
Task
Draw and complete a table to compare structure and
function of
arteries, veins and capillaries.
Artery
Veins
Capillary
Function
Transport blood Transport blood away
towards the heart from the heart
Connect arteries
to veins
Wall
Thick, muscular,
elastic
Thin
One cell thin
Lumen
Narrow
Wide
Size of Red blood
cell
Pressure High
Low
Low
Valves
Yes
No
No
(Heart) Valves
 Valves make
things go in
only 1
direction
Heart Valves
 Blood should
flow in 1
direction only
 Between left
atrium and
left ventricle
 Also called
Bicuspid
valve
Mitral Valve
Tricuspid Valve
 Between right
atrium and
right ventricle
Semi Lunar Valve
 Between right
atrium and
right ventricle
 In aorta and
Pulmonary
artery
Heart Valve operation
Artificial Heart Valve