Introduction to the Cardiovascular System - part 7 pps

... Plexus Vein AV anastomosis FIGURE 7- 1 4 Anatomy of the cutaneous circulation. Arteries within the subcutaneous tissue give rise to either arte- rioles that travel into the dermis and give rise to capillary ... 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...

Ngày tải lên: 11/08/2014, 11:22

... 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 ... Plexus Vein AV anastomosis FIGURE 7- 1 4 Anatomy of the cutaneous circulation. Arteries within the subcutaneous tissue give rise to either arte- rioles that travel into...

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...

Ngày tải lên: 11/08/2014, 00:20

... 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 ... cardiac systole and increase during diastole (Fig. 7- 7 ). Therefore, most of the blood flow to the myocardium occurs dur- ing diastole. The reason that coronary flow is influenc...

Ngày tải lên: 11/08/2014, 11:22

... 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 volume. Therefore, the net effect ... vein into the right atrium, passed into the right ventricle, then positioned within a branch of the pulmonary artery. There is one opening (port) at the tip of the cath...

Ngày tải lên: 11/08/2014, 11:22

... 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...

Ngày tải lên: 11/08/2014, 00:20

... 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 s...

Ngày tải lên: 11/08/2014, 00:20

... 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...

Ngày tải lên: 11/08/2014, 00:20

... 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