Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / Quantitative relationships between blood flow velocity, vessel diameter, width of the peripheral plasma layer and induction of thrombus formation were studied in small blood vessels of the retrolingual membrane and intestinal mesentery of the frog, Rana Pipiens, and of the cheek pouch of the golden hamster, Mesocricetus auratus.
Blood flow velocity was measured by a modification of the technique described by Hugues (Arch. Int. de Physiol. 61: 565, 1953). Internal vessel diameters and widths of the total peripheral plasma layer were measured with an ocular micrometer. Thrombus thresholds were determined by graded electrical stimulation.
Determinations were made on 202 vessels in retrolingual membranes of frogs prepared by single pithing. In 95 arterioles (diameters from 10 to 40 microns), the mean flow velocity was 2.84 mm/sec. and the mean volume flow rate, 1.68xl0-3 cu mm/sec. The mean width of the total peripheral plasma layer was 3.6 microns and its ratio to mean vessel diameter was 1:6. In 107 venules (diameters from 10 to 50 microns), the mean flow rate was 1.20 mm/sec. The mean volume flow rate was 1.02x10-3 cu mm/sec. The mean width of the total peripheral plasma layer was 4.1 microns and its ratio to mean vessel diameter was 1:7.4. The ratios of mean arterial to mean venous velocity and volume flow were 1:2.3 and 1:1.6 respectively.
Measurements were made on 100 mesenteric vessels of frogs prepared by single pithing. In 50 arterioles (diameters from 15 to 45 microns), the mean velocity was 3.77 mm/sec. The mean volume flow was 3.05xlo-3 cu mm/sec. The mean width of the total peripheral plasma layer was 2. 7 microns and its ratio to mean vessel diameter was 1:11.5. In 50 venules (diameters from 20 to 50 microns), the mean velocity was 1.55 mm/sec. and the mean volume flow rate, 1.76x10-3 cu mm/sec. The mean width of the total peripheral plasma layer was 6.7 microns and its ratio to mean vessel diameter was 1:5.3. The ratios of mean arterial to mean venous velocity and volume flow were 1:2.3 and 1:1.7 respectively.
A total of 109 mesenteric vessels were studied in frogs anesthetized with urethane. In 55 arterioles (diameters from 15 to 45 microns), the mean velocity was 3.28 mm/sec. The mean volume flow was 2.87x10-3 cu mm/sec. The mean width of the total peripheral plasma layer was 3.2 microns and its ratio to mean vessel diameter was 1:9.3. In 54 venules (diameters from 20 to 50 microns), the mean flow rate was 1.61 mm/sec. and the mean volume flow, 1.83x10-3 cu mm/sec. The mean width of the total peripheral plasma layer was 5.6 microns and its ratio to mean vessel diameter was 1:5.9. The ratios of mean arterial to mean venous velocity and volume flow were 1:2.0 and 1:1.5 respectively.
In these three series of studies in the frog, no relationship was clearly apparent between velocity and either vessel diameter or width of the peripheral plasma layer in arterioles. Suggestions of a direct relationship between velocity and peripheral plasma layer in veins, however, were evident. In all cases, and in both arterioles and venules, vessel diameter and peripheral plasma layer were clearly and directly related.
The effects of flow velocity changes on width of the total peripheral plasma layer in individual vessels were studied in 26 arterioles of the hamster cheek pouch. Blood flow was varied by means of a cuff described by Copley (Biorheology 1: 3, 1962). A direct relationship between velocity and width of the peripheral plasma layer was clearly demonstrated.
Thrombus thresholds were determined in mesenteric vessels of the frog. In 103 arterioles (diameters from 20 to 140 microns), the mean strength of stimulus necessary to produce a platelet thrombus was 24.8 volts with an amperage of 0.18 milliamperes. In 100 venules (diameters from 20 to 140 microns), the mean strength of stimulus necessary was 20.7 volts with an amperage of 0.12 milliamperes. Possible relationships of thrombus thresholds to flow velocity in mesenteric arterioles and venules are discussed. / 2031-01-01
| Identifer | oai:union.ndltd.org:bu.edu/oai:open.bu.edu:2144/34550 |
| Date | January 1964 |
| Creators | Grillo, Gene Patrick |
| Publisher | Boston University |
| Source Sets | Boston University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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