Distribution of Maternal and Fetal Blood Flow within Cotyledons of the Sheep Placenta

<p>These studies explore the distribution of blood flow among small samples of placental tissue. Labeled microspheres (14 ± 1 pm) were Injected Into the left ventricle of six un-anesthetized ewes and Into the jugular vein of the fetus In utero. A total of 3,576 samples weighing 31. +11. (S.D.) mg were taken from seventeen cotyledons and counted for flow labels. Maternal and fetal flow within the cotyledons were both normally distributed with standard deviations of 44%. The maternal/ fetal flow ratio was less than 0.5 In 9% of the cotyledon, between 0.5 and 1.5 In 70%, and greater than 1.5 In 21%. Errors due to the method were estimated to contribute less than 10% of the flow variances. Maternal and fetal flows were significantly correlated (r = 0.57, p < .001). Spatial flow patterns were visualized using computerized Image processing. The distribution of maternal and fetal flow may be a sensitive determinant of water transfer, and the distribution of their ratio explains about 50% of the uterine—umbilical venous oxygen tension gradient. Analysis of the correlation between samples vs. the distance separating them suggested a weight of roughly 125 mg for hypothetical placental regulatory units.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Bioinformatics & Computational Biology

Year

1980

Authors dc:creator

• Power, Gordon G.
• Dale, P. Steven
• Nelson, Paul S.

Contributors dc:contributor

• Ivan R. Neilsen
• Gordon G. Power
• C. Duane Zimmerman
• S. Andrew Yakush
• Paul Y. Yahiku

• Medical Biomathematics and Biometrics
• Maternal-Fetal Exchange; Fetal Blood; Placenta

Statement dc:rights

• This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Language dc:language

English

Repository record dc:identifier

https://scholarsrepository.llu.edu/etd/1194

OAI identifier oai:identifier

oai:scholarsrepository.llu.edu:etd-2708