BIO 3302 Lecture 6: Lecture 6 - Manipulation of circulatory system
16 Oct 2017
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Document Summary
At a capillary, filtration is driven by fluid pressure whereas absorption reflects the osmotic gradient. Frank-starling hypothesis describes fluid circulation at a capillary. Frank-starling describes the relationship between venous return and stroke volume. Sympathetic innervation of pre-capillary sphincters regulates blood flow within a capillary bed. Pre-capillary sphincters are innervated by local factors eg metabolic factors etc. Whereas alpha1 adrenergic receptors cause vasoconstriction, vasodilation is achieved by beta1 adrenergic receptors. Beta1 is in the heart, blood vessels have alpha1 and beta2. Type of sensory receptor that determines pressure based on stretch in the vessel wall. Want to bring blood pressure to set point. Example drank lots of water = higher blood pressure. Sympathetic innervates the sa node as well to decrease stroke volume. Decreasing venous tone --> lower cardiac output, decrease supply of blood to heart. Use beta blockers to inhibit beta 1 receptors. Limit sympathetic nervous systems ability to increase heart rate and cardiac output.
