Tissue Fluid Flow Research Articles

Comparative characteristics of the creep properties of human compact bone tissue under various specimen storage and testing conditions

Compact bone tissue is a structurally inhomogeneous material with a multiplicity of pores and channels through which, under physiological conditions, blood, lymph, and tissue fluid flow. According to [I], the fresh bone tissue of people of medium age contains 20% water by weight. However, experimenters mainly employ autopsy material which under room conditions has a tendency to dry out, with consequent changes in the mechanical properties. Investigations have shown that drying in air increases the strength of the bone tissue in tension and bending, increases the modulus of elasticity and ha=dness, and reduces the specific deformation energy and shear strength.

Experimental Studies of the Translocation of Plutonium from Simulated Wound Sites in the Rat

Wound contamination with plutonium was simulated in rats by injection into either muscle or subcutaneous tissue. The distribution after the injection of plutonium nitrate indicated that: (i) clearance from the contaminated tissue was due mainly to the movement of soluble complexes of plutonium, principally to the skeleton and liver, but also involved slower movement of polymerized, particulate plutonium to lymph nodes; (ii) clearance of soluble plutonium, and hence the overall state of clearance, was dependent on the tissue fluid flow through the contiminated tissue and the mass of plutonium deposited; (iii) lymphatic clearance of particulate plutonium resulted in the release of some particles into the circulation and subsequent uptake by the liver. Intramuscular deposition of small plutonium dioxide particles (approximately 1 nm in diameter) resulted in a greater rate of clearance of plutonium than deposition of the nitrate. Although the solubility of these particles was evident from the level of skeletal uptake of plutonium, a high level of excretion indicated that some plutonium was filtered into the urine in an undissolved form.

Distribution and Transport of Varied Substances in the Dog Kidney in Vivo: Implications with Regard to Metabolic Activities

Some matters bearing on renal metabolic activities have been reviewed. The distribution of solutes to various regions of the kidneys depends not only on convection by blood and tissue fluid flow but also on diffusion of the solutes in the tissues. Lipid solubility may play a significant role in tissue diffusion in that substances with significant lipid solubility may have access to more direct pathways than strictly hydrophilic substances. Glucose utilization by the kidney is significant. Glucose may contribute as much as 25 per cent and lactate, through decarboxylation, as much as 30 per cent of the renal carbon dioxide production. Together, glucose and lactate may account for about 50 per cent of the total renal carbon dioxide production. There is evidence that there is substantial lactate production by the kidney as well as gluconeogenesis. The conditions for luminal and anti-luminal cell surface interactions with D-glucose differ with regard to configuration, conformation and phlorizin affinity. Possible pathways of entry of glucose into metabolic activities are briefly considered.

Alveolo Bronchiolar Transport; Observations and Hypothesis of a Pathway

Defense of the bronchopulmonary tree against inhaled particles depends primarily on in situ phagocytosis and mechanical transport. Whereas the process of phagocytosis and mucociliary activity are fairly well understood, there remains a great deal of uncertainty regarding the mechanism of fluid, cellular and particulate transport from the alveolus to the mucociliary stream of the bronchioles. Several mechanisms have been invoked to account for alveolar transport: 1) amoeboid motion of macrophages toward the bronchiolar exit; 2) traction force placed on cohesive respiratory tract secretions by the propelling force of the bronchial cilia; 3) surface tension gradients from alveoli to bronchi, and 4) mechanisms of tissue fluid flow by lymphatic drainage.

Tissue fluid movement in compact bone.

AbstractThorotrast (colloidal thorium dioxide) was released into tibial marrow cavities of 12 adult cats and into the tibial nutrient arteries of ten adult cats. Following regular intervals the tibiae were removed, fixed, decalcified in formic acid, and prepared histologically.The label indicated the general tissue fluid drainage of the tibia is in the perivascular connective tissue of Volkmann's canals from the marrow cavity to the periosteal lymphatic vessels.The tissue fluid flow appears to pass from the Haversian vessel through the canalicular‐lacunar complex to the peripheral lacunae of the osteone. Its path from this point has not been observed.