dejan tkalec mentor: a. Žmega č horvat blood vessels
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Dejan TkalecMentor: A. Žmegač Horvat
Blood vessels
What are blood vessels?intricate networks
of tubes that transport blood throughout the entire body
Types of vessels:ArteriesVeinsCapillariesSinusoids
ArteriesTransport blood away
from the heartCarry oxygenated
blood Have relatively narrow
lumensHave relatively more
muscle/elastic tissueTransport blood under
higher pressure Do not have valves
(except for the semi-lunar valves of the pulmonary artery and the aorta)
VeinsTransport blood
towards the heartCarry de-oxygenated
bloodHave relatively wide
lumens Have relatively less
muscle/elastic tissueTransport blood under
lower pressureHave valves
throughout the main veins of the body (except venae cavae)
HistologyArteries and veins have the same structure:1.Tunica intima: single layer of simple
squamous endothelial cells, surrounded by a thin layer of elastic bands – internal elastic lamina
2.Tunica media (thickest layer): circularly arranged elastic fibers, connective tissue, polysaccharide substances surrounded by external elastic lamina; rich in vascular smooth muscle (especially in arteries)
3.Tunica adventitia: entirely made of connective tissue; contains nerves that supply the vessel
Functions Transporting blood away from the heart Transporting oxygenated blood across the body Transporting blood from arteries to capillaries Draining blood from capillaries into veins and
exchanging oxygen, carbon dioxide, water and salt between the body and surrounding tissues
Arterioles - main regulators of blood pressure and flow
Capillaries - assist in supplying body tissues with necessary components of blood
Common problemsAneurysm - weak spot in the wall of an
artery Atherosclerosis - narrowing of the
arteries caused by plaque deposits Heart disease - lack of blood supply to the
heart because of narrowed arteriesHigh blood pressure - can be caused by
obesity, diabetes, rich salt diet, smoking, high cholesterol, kidney disease...
Varicose veins - problems with valves that stop blood from running backwards
Aorta Largest artery in the body, originating from
the left ventricle of the heart and extending down to the abdomen, where it branches off into two common iliacs
Usually divided into 5 segments: 1.Ascending aorta2.Arch of aorta3.Descending aorta4.Thoracic aorta5.Abdominal aorta
Other major arteries
References http://biology.about.com/library/organs/
heart/blblood.htmhttp://en.wikipedia.org/wiki/Blood_vesselhttp://www.ivy-rose.co.uk/HumanBody/
Blood/Blood_Vessels.phphttp://www.ehow.com/
about_5110377_functions-blood-vessel.htmlhttp://video.about.com/heartdisease/How-
the-Heart-Functions.htm