Download hh-phy-hea-arteries-capillaries-and-veins

The cardiovascular
system, diabetes and
obesity
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Overview
• This topic looks at the structure and function of the
cardiovascular system with an emphasis on diabetes, obesity
and their effects on the system.
• There are 4 areas of study
• The structure and function of arteries, capillaries and veins
• The structure and function of the heart
• The pathology of cardiovascular disease
• Blood glucose levels and obesity
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The structure and function of
arteries, capillaries and veins
• What do you know already?
• Label the diagrams provided and write any notes
• What you need to know?
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Structure of all 3 types of blood vessel
Flow of blood in the vessels including pressure changes
The exchange of materials between blood vessels and tissues
How the lymph system works with the circulation
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Heart pumps blood
2 circulations (lungs/body)
Arteries
Capillaries
Veins
Blood variety of reds
Diagrams Oxygenated blood (red)
Diagrams Deoxygenated blood (blue)
Diagrams arteries red except pulmonary artery
Diagrams veins blue except pulmonary vein
Arteries blood away from heart
Veins blood towards the heart
Arteries>arterioles>capillaries>venules>veins
Pressure changes from high to low
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Arteries
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Arteries
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Outer layer of connective tissue with elastic fibres
Middle layer with smooth muscle and elastic fibres
Inner lining is the endothelium
Lumen (channel) is relatively narrow
Elastic walls stretch and recoil with surge of blood
Smooth circular muscle can contract (vasoconstriction)
Smooth circular muscle can relax (vasodilation)
Blood flow can be controlled
Pressure higher than capillaries and veins
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Capillaries
• Link arteries to vein
• Allow exchange of
substances with tissues
• Endothelium 1 cell thick
• Close to all cells
• O2, dissolved food, ions
• CO2, metabolic waste
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Tissue fluid
• Fluid is squeezed out of the blood from capillaries
• Difference in pressure between capillary and tissue cells
causes fluid to leave capillaries (plasma)
• Tissue fluid contains glucose, amino acids, respiratory
gases and ions
• Tissue fluid contains very little or no protein, it is too big
to be passed out of the capillaries
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Veins
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Veins
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Outer layer of connective tissue with elastic fibres
Middle layer with smooth muscle
Elastic fibres and muscle wall much thinner than arteries
Not very elastic
Wider lumen (channel) than arteries
Lower pressure than arteries
Valves prevent backflow of blood
Surrounding muscle tissue helps move blood by contractions
Pressure lower than capillaries and arteries
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Lymphatic system and circulation
• Some excess fluid
enters the
lymphatic vessels
• Lymph fluid is
moved by muscles
compressing
lymph vessels
• Lymph fluid is
returned to veins
in the arms via
lymphatic ducts
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What do you know?
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What are the 3 types of blood vessel?
Describe them (diagram and label)
Describe their function and relate to structure
Describe and explain pressure changes in system
What is vasoconstriction?
What is vasodilation?
Why do veins have valves?
What is tissue fluid?
What is lymph?
What does the lymphatic system do?
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