Introduction to the Cardiovascular System - part 3 pdf

... causes the end-diastolic pressure- volume curve to shift up and to the left, as shown in Figure 4-2 7. This shift will reduce the end-diastolic volume and increase the end-diastolic pressure at the ... of the ventricles. Ejection occurs because the total energy of the blood within the ventricle exceeds the to- tal energy of blood within the aorta. The total ene...

Ngày tải lên: 11/08/2014, 00:20

... within the AV node, which might prolong the P-R inter- val. Therefore, taking the patient off the ␤-blocker might improve AV nodal conduction and thereby decrease the P-R interval to within the ... filament. Ch 03_ 04 1-0 58_Klabunde 4/21/04 10:57 AM Page 43 wave of the QRS). About 20 milliseconds later, the mean electrical vector points down- ward toward the apex (vecto...

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... gradient, to enter the cell. As the m-gates open, the h-gates begin to close; however, the m-gates open more rapidly than the h-gates close. The difference in the opening and closing rates of the two ... depolarization to thresh- old opens the m-gates (voltage activated), thereby opening the channel and enabling sodium to enter the cell. Shortly thereafter, as t...

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... reflex. Mechano- receptor Mechano- receptor Mechano- receptor Chemo- receptor Chemo- receptor Chemo- receptor 2 Chemo- receptor Chemo- receptor Nociceptor Nociceptor Various Proprio- ceptor Proprio- ceptor, Chemo- receptor Thermo- receptor Thermo- receptor Internal Carotids ... baroreceptors) enter the medulla at the nucleus trac- tus solitarius (NTS), which projects inhibitory interneuron...

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... the autoregulatory range). This is because of the strong capacity of these organs to autoregulate and their ability to escape sympathetic vaso- constrictor influences. The autoregulatory re- sponse ... ␤ 2 -adrenoceptors) or in- creases (via vascular ␣ 1 and ␣ 2 -adrenocep- tors) systemic vascular resistance, depend- ing upon the plasma concentration. • The renin-angiotensin-aldo...

Ngày tải lên: 11/08/2014, 00:20

... muscle, the muscle cells adjacent to the capillary take up the oxygen for use by the mitochondria. Consequently, little oxygen dif- fuses all the way through one cell to reach an- other. Therefore, ... only 25 35 mm Hg, which cor- responds to a 30 % to 60% loss of oxygen con- tent of the blood. Therefore, substantial amounts of oxygen diffuse out of the blood be- fore...

Ngày tải lên: 11/08/2014, 00:20

... required to switch over to anaerobic gly- colysis for the production of ATP. Acidosis stimulates peripheral and central chemore- ceptors, leading to increased sympathetic ac- tivity to the systemic ... stimulation (␤ 1 -adrenoceptor mediated) and peripheral vasoconstriction ( - adrenoceptor mediated), and contributes to the release of renin by the kidneys through re- nal...

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... PHYSIOLOGICAL ACTIONS OF ENDOTHELIN-1 Endothelin-1 (ET-1) is synthesized from an endothelin precursor (big ET-1 or pro-ET-1) and cleaved to ET-1 by endothelin convert- ing enzyme (ECE) found on the endothelial cell ... are the same in the pre- and post- stenotic segments). Therefore, KE is the same in the post- and pre-stenotic segments. There is, however, an additional loss of PE...

Ngày tải lên: 11/08/2014, 00:20

... Supplemental 6 /3/ 04 6 :31 PM Page 11 afterload (particularly aortic diastolic pres- sure) enables the end-systolic volume to de- crease slightly, but not enough to overcome the decline in end-diastolic ... be- cause of the large stroke volume ejected into the aorta. As long as the ventricle is not in fail- ure, normal end-systolic volumes can be sus- tained; however, the end...

Ngày tải lên: 11/08/2014, 00:20

... although there are three driven and steered wheels, only two motors are used in total. The one translation motor sets the speed of all three wheels together, and the one steering motor spins all the wheels ... Because of to slop and backlash in the drive train, whenever the drive motor engages, the closest wheel begins spinning before the fur- thest wheel, causing a small ch...

Ngày tải lên: 10/08/2014, 05:20