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Unformatted text preview: * Circulatory ( Closed ) System has 3 Basic Components * I. ) Heart: organs that pump blood to tissues, w/ pressure , located in Thoracic cavity ``````````` + Cover by a double walled sac = Pericardium- Protect the heart, Anchor it to surrounding, Prevent from overfilling- Has serous fluid between the Pericardial cavity- allow the two layers to slide w/o causing Friction . + Myocardium = cardiac muscle bundles that spirally arranged , and when contracts-results in a wringing effect that pushes blood upward to arteries . They have fibrous connective tissue that form fibrous skeleton for the heart . + Two halves divided by a Septum = (to prevent blood from mixing from O2- rich-Left to O2-poor-Right sides; b/c we want maximum amount of O2)- But, 4 chambers > 2 upper + 2 lower > Superior (left&right) Atria- Upper chambers = receive blood returning to the heart in Veins ~ Contraction in Atria contributes very little in Propulsion of the blood into ventricles. > Inferior (L&R) Ventricles- Lower..cha.. = Major propelling /pumping blood from the heart-out to the circulation through Arteries Dual System: * Pulmonary circulation heart to lungs (where we Oxygenated the blood) * Systemic circulation heart to body - So, basically, Blood leaving Right-Deoxygenated side of Heart go in Pulmonary circulation, Lungs return back to heart in Atria, through Veins Left-Oxygenated side then come out of the heart in the Ventricles through Arteries and go to Systemic circulation to feed ur body- Muscle wall on Left side is much Thicker b/c: Right side-> pumps only t o Pulmonary = so lil work, Low pressure + resistance . Left side-> pumps to entire body = more work, High pressure + resistance . II.) Blood Vessel : where blood in moving through ```````````````- Arteries carry (De-Oxide) blood away from the heart- Veins return blood to the heart * Heart Created Pressure Blood flows from High pressure (in aorta ) -> Low pressure (in venae cavae ) * Blood Flow is Dependent on Pressure Gradients and Resistance r found at the end of the Vessel :- Resistance opposition to blood flow due to Friction between fluid & vessel walls. ( Inverse relationship ) between Flow & Resist. (Resist-increase-> Flow decrease ) + Three Component Determining Resistance: 1.- Vessel radius: Inverse relationship ( Vasoconstriction-> Decrease hole size = Greater the Resistance) ( Vasodilation-> Increasing-Bigger hole = Weaker the Resistance) 2.- Vessel Length: Direct relationship (Longer = More resist.) 3.- Viscosity of the blood: determine by # of Red Blood Cells Direct Relation....
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This note was uploaded on 07/27/2011 for the course BIOL 3324 taught by Professor Ziburkus during the Fall '07 term at University of Houston.
- Fall '07