Introduction to the Cardiovascular System - part 6 pps

... 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 ... 6- 9 ; Table 6- 3 ). The transient in- crease in heart rate is due to norepinephrine binding to ␤ 1 -adrenoceptors in the sinoatrial node, whereas the secondary bradycardia...

Ngày tải lên: 11/08/2014, 11:22

... 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 ... 6- 9 ; Table 6- 3 ). The transient in- crease in heart rate is due to norepinephrine binding to ␤ 1 -adrenoceptors in the sinoatrial node, whereas the secondary bradycardia...

Ngày tải lên: 11/08/2014, 00:20

... 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...

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... 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, ... 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 the blood reaches...

Ngày tải lên: 11/08/2014, 11:22

... Supplemental 6/ 3/04 6: 32 PM Page 12 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 en...

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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...

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 ... heading di- rectly toward the positive electrode, gives the greatest positive deflection. As the vector moves around the axis to the left, and therefore moves away from th...

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... 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 ... occurs because the total energy of the blood within the ventricle exceeds the to- tal energy of blood within the aorta. The total energy of the blood is the su...

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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 ... falls. The curve representing the frequency of barore- ceptor firing in Figure 6- 6 is the integrated re- cepto...

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... through the capillary loops and the venous plexus. In addi- tion to sympathetic neural control, the resis- tance vessels and AV anastomoses are very sensitive to ␣-adrenoceptor-mediated vaso- constriction ... 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 the blood reac...

Ngày tải lên: 11/08/2014, 00:20