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Regulation of BP. Rene Kosi School of Medicine, 2nd year 2013/2014 Mentor: A. Žmegač Horvat. What is BP?. Force exerted by blood against any unit area of the vessel wall Heartbeat -> systolic -> diastolic. How do we measure it?. Auscultatory method.
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Regulation of BP Rene Kosi School of Medicine, 2nd year 2013/2014 Mentor: A. Žmegač Horvat
What is BP? • Forceexertedbybloodagainstanyunitareaofthevesselwall • Heartbeat -> systolic -> diastolic
How do we measure it? • Auscultatory method
So, how does our body control BP? • 2 mechanisms: • Short-term regulation • Long-term regulation
Short-term regulation • Negative feedback reflex mechanisms • 1) Baroreceptor reflexes • Stimulated when stretched • Signals to tractus solitarius in medulla • Respond to rapid changes of pressure
2) Circulatory reflex • Inhibit the vasoconstrictor center • Excite the vagal parasympathetic center • Vasodilatation • Decreased heart rate
Long-term regulation • If blood volume increases and vascular capacitance is not altered, arterial pressure will also increase • Pressure diuresis
Near Infinite Feedback Gain • Until the pressure returns exactly to the equilibrium point
Increase in salt intake: • Stimulates thirst center in the brain • Increased secretion of ADH • Pressure natriuresis
Sources: • Guyton and Hall Textbook of Medical Physiology, 12th edition, 2012 • Me