The body's initial response to hypovolemic shock involves compensatory mechanisms aimed at maintaining perfusion:
1. Sympathetic Nervous System Activation: This leads to the release of catecholamines, causing vasoconstriction and increased heart rate. Histologically, this can be seen as changes in the smooth muscle cells of blood vessels.
2. Renin-Angiotensin-Aldosterone System (RAAS): Activation of the RAAS leads to sodium and water retention to increase blood volume. Histologically, the kidneys may show signs of hyperplasia in the juxtaglomerular cells.
