BIOM20002 Lecture Notes - Lecture 47: Pulmonary Vein, Pulmonary Circulation, Skeletal Muscle
Distribution of dissolved gases and other molecules for nutrition, growth and repair,
waste removal
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Chemical signaling to cells by means of circulating hormones
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Mediate inflammatory and host defense responses against invading microorganisms,
transport clotting factors etc.
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Conserve or release heat hear skin surface. Cutaneous vasodilation to cool
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Functions
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Blood in veins carries oxygen: true. It carries some oxygen (but not along)
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Well-oxygenated blood is carried by which blood vessels: aorta, pulmonary vein
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Circulatory system is parallel: systemic and pulmonary circulation
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Systemic is longer so more resistance. So higher pressure required
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Many capillary beds. Can individually change blood flow to each one. e.g. kidneys, skeletal
muscle
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How much blood flows past a certain point in a given time
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Flow is same for all parts of system. What you put in (cardiac output) is same is what you get
out
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Width - can be changed quickest by body
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Viscosity
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Length
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Decreases with increased resistance
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Increases with increased difference in pressure. Cannot flow if no pressure difference
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Can make blood vessels longer by angiogenesis but not readily changed
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1 and 3 have the largest pressure difference (75mmHg), so highest flow
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3 - short, wide tube has least friction
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Flow is proportional to 1/R, where R = 8Lη/πr4(η=viscosity)
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Radius is thus a strong determinant of flow
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Poiseuille's law
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Blood flow
Tone in smooth muscles of blood vessels: Basal state of muscle contraction
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Tone
47 Properties of the cardiovascular system
Friday, September 19, 2014
9:25 AM
HSF Page 1
Document Summary
Distribution of dissolved gases and other molecules for nutrition, growth and repair, waste removal. Chemical signaling to cells by means of circulating hormones. Mediate inflammatory and host defense responses against invading microorganisms, transport clotting factors etc. Well-oxygenated blood is carried by which blood vessels: aorta, pulmonary vein. Circulatory system is parallel: systemic and pulmonary circulation. Can individually change blood flow to each one. e. g. kidneys, skeletal muscle. How much blood flows past a certain point in a given time. Flow is same for all parts of system. What you put in (cardiac output) is same is what you get out. Width - can be changed quickest by body. Can make blood vessels longer by angiogenesis but not readily changed. 1 and 3 have the largest pressure difference (75mmhg), so highest flow. 3 - short, wide tube has least friction. Flow is proportional to 1/r, where r = 8l / r4 ( =viscosity) Radius is thus a strong determinant of flow.
