Arteries, Capillaries and Veins
Arteries, Capillaries and Veins
Arteries – vessels carrying blood away from the
heart
Capillaries – located at the end of arteries, they
are tiny vessels where the exchange of nutrients
& Oxygen and waste products between the
blood and cells take place
•Veins – vessels carrying blood returning
toward the heart
Artery to Capillary to Vein
How do arteries assist the heart in
pumping blood?
An artery is made of a layer of muscle that can
expand and contract. When the heart beats the
artery relaxes and the vessel opens, when the heart
relaxes the artery contracts and the vessel narrows
helping push the blood along.
The wall of the artery is made of
muscle that can dilate or constrict
to assist in blood flow
Describing a Capillary
Capillaries are very thin and fragile. They
can be only one cell wide and blood cells
line up one at a time pass through. Oxygen,
nutrients and wastes are exchanged
between blood and body cells through the
thin cell walls
Capillary
Why do veins have valves?
Veins have one way valves that open to allow
blood to pass through when the heart beats
and then close to prevent blood from back
sliding when the heart relaxes.
This is most important in the legs as the
blood is pumped uphill to return to the
heart. The valves prevent blood from
backsliding due to gravity.
What are Varicose Veins?
Varicose veins can develop anywhere but
most commonly it occurs in the legs, ankles
and feet. It is the enlargement of the vein
caused by pooling of blood. They are seen
through the skin as blue and sometimes
bulging or gnarled.
What causes Varicose Veins?
The most common cause of varicose veins
occurs as a result of weak one way valves in
the vein allowing blood to backslide and
pool in the lower parts of the legs.
Are Varicose veins dangerous
Usually varicose veins are not dangerous to
health. They can itch and burn and could
result in skin ulcers from scratching. In
more serious cases blood clots can form
which can result in serious health
conditions.
Treatment of Varicose Veins
Exercise helps to reduce the effect of
varicose veins by keeping the veins supple.
Wearing elastic hose can help the veins keep
from enlarging and assist in keeping the
valves sealed.
Medicines , Surgery or Laser treatments may
be needed in severe cases to dissolve and
remove the vein.