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Unformatted text preview: I.) Heart: Located in Thoraic cavity . 2 halves divided by Septum Your answer is CORRECT. The skeletal muscles for breathing are located in the walls of the thoracic cavity .- True L-R L-R * 4 Chambers ( Superior-Atria vs. Inferior- Ventricles<- Major Propelling from heart ) + * Dual system ( Pulmonary & Systemic circulation <- here the muscle is stronger )- So basically,Start in Right-De-Oxygenated half of the heart (R. Atrium + Vent.)- To Pulmonary Circulation (Pulmonary Arteries, Capillaries 4 gas exchange, and Pulmonary Veins)- Return to Left half-Oxygen rich (L. Atrium + Ventricle)- To Systemic circulation (Aorta-Highest press, arteries, Vena Cavae-Lowest press.) Veins-> blood return through heart in Veins Arteries-> carry blood away from Heart. Your answer is CORRECT. ! ? ! Blood returning from the lungs ! ? ! enter Left Atrium + rich O2 ! ? ! Blood returning from the systemic circulation ! ? ! - enter Right Atrium + poorly O2 Your answer is CORRECT. Which of the following is true regarding the heart: The heart requires its own circulatory circuit to obtain oxygen and nutrients from the blood because it can not obtain them from the blood being pumped in the chambers + Pericardium = Cover the Heart, Protect it, Anchor it, and Prevent it from Overfiling Since its Double layer The pericardial cavity has Serous fluid that allow the layers to slide w/o causing Friction. + Myocardium = cardiac muscle that when contracts result in Wringing Effect that pushes blood upward to arteries. Have Fibrous connective tissue that form fibrous skeleton for the heart. Cardiac Muscle ( striated ) so, similar to skeletal muscle . But Uninucleat e and ````````````````````` Smaller than Skeletal. > Theyre Branched cell & Connected by Intercalated discs.- Desmosomes = mechanical junctions that hold cells together. - Gap junctions = allow AP to spread between cells. > Some of Cardiac muscle are self-generated AP, which spread to other cells in.. > T-tubules are Large r than found in Skeletal > 1/3 of Volume of Cardiac muscle cell are Mitochondria. . * Ca+2 is the Key-> when AP enters, Voltage gated Ca+2 opens Ca+2 comes in and induces more Ca+2 release through RyR .. * Electrical activity of the heart heart beats Rhythmically as result of AP ( 2 Types ) 1. Contractile cells: (99% of muscle cells of heart). Do mechanical work of pumping Do Not INITIATE AP-but will response to them . >( ITS AP ): Rapid rising Phase = Voltage-gated Na+ channel open to allow Na+ in .- Plateau Phase = under responsible of influx Ca+2 , even though Na+ is now close, Ca+2 can still moves in and Decrease K+ permeability. - Rapid falling Phase = Ca+2 begin to Close and K+ begins to Open Your answer is CORRECT....
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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