In hypovolemic shock, the body experiences a significant loss of blood volume, leading to decreased perfusion of tissues and organs. The physiological response to hypovolemic shock includes several compensatory mechanisms aimed at maintaining blood pressure and ensuring adequate blood flow to vital organs.
One crucial response is the constriction of arterioles in different parts of the body to divert blood to essential areas. Specifically, in the kidneys, afferent arteriolar constriction occurs.
Afferent Arteriolar Constriction: In hypovolemic shock, the body activates the sympathetic nervous system and releases catecholamines like norepinephrine. These mediators cause vasoconstriction, particularly affecting the afferent arterioles of the kidneys. This diminishes renal blood flow to redirect blood towards more vital organs such as the heart and brain.
Other options mentioned, such as increased blood flow to the kidney and normal cardiac output, do not occur in hypovolemic shock.
Option
Explanation
Afferent arteriolar constriction
Correct; occurs to conserve blood flow for vital organs.
Efferent arteriolar constriction
Not typical; involves different regulatory mechanisms.
Increased blood flow to kidney
Incorrect; blood flow decreases to conserve volume.
Normal cardiac output
Incorrect; cardiac output decreases during hypovolemic shock.