Collagen and elastin fibers in human pulmonary alveolar walls.

The morphology and morphometric data of collagen and elastin fibers in the pulmonary alveolar walls are presented. Specimens were obtained from postmortem lungs quick-frozen at specified transpulmonary pressures. Collagen was stained by silver, and elastin was stained by orcein.

Morphometry of cat's pulmonary arterial tree.

Morphometic data of the pulmonary artery in the cat's right lung are presented. Silicone elastomer casts of cat's right lung were made, and measured, counted and analyzed. The Strahler system is used to describe the branching pattern of the arterial vascular tree.

Changes in arteriole in acute and chronic hypoxic pulmonary hypertension and recovery in rat.

After 1 h of exposure to 0.5 atm of pressure, the electron microscopy of intra-acinar arterioles of the young female adult rat showed edema and subendothelial blebs. Pulmonary hypertension developed rapidly with an increase in hemoglobin, hematocrit, and right ventricular weight.

Morphometry of cat pulmonary venous tree.

Morphometric data of the pulmonary veins in the cat right lung are presented. Silicone elastomer casts of the right lungs of five cats were made, measured, counted, and analyzed. The Strahler system is used to describe the branching pattern of the vascular tree.

Patency and compliance of pulmonary veins when airway pressure exceeds blood pressure.

Our measurements on cat's lung show that pulmonary veins and venules are not collapsible, but remain open when the alveolar gas pressure (PA) exceeds the local blood pressure (Pv). Their compliance constants show no discontinuity as Pv falls below PA. The capillaries, however, do collapse when PA greater than Pv.

Computer-derived image compositing.

A computer-derived composite image is obtained of the details contained in successive photomicrographs taken by optical sectioning of the collagen networks in the pulmonary interalveolar wall. Three-dimensional information is therefore contained in a two-dimensional portrayal, providing a basis for computer digital analysis otherwise not readily available.

Redistribution of canine left ventricular myocardial blood flow in unloaded systole.

The left coronary arteries of dogs were cannulated and perfused with blood from support dogs. The experimental hearts were unloaded by severing the aortas to maximize strains and minimize fiber stress. In each heart we compared the transmural distribution of blood flow in two states: (1) provision of perfusion pressure (40 mm Hg) only during systole and then (2) provision of perfusion pressure throughout the cardiac cycle.