If the radius of a blood vessel decreases by half due to vasoconstriction, which consequence follows regarding blood flow, assuming constant pressure gradient and blood viscosity?

💡 Explanation

The effect of vessel radius on blood flow is described by Poiseuille's Law, where flow is proportional to the radius to the fourth power. Because the radius decreases by half, the flow decreases by (1/2)^4 = 1/16; therefore, blood flow decreases sixteen-fold, rather than remaining constant or decreasing linearly.

• A patient reports difficulty learning new motor skills after a stroke impacted their hippocampus; which sleep-related effect explains this deficit?
• If a patient exhibits increasing insulin resistance in peripheral tissues despite normal pancreatic beta cell function, which adaptation within muscle cells causes reduced glucose uptake?
• Why does escalating nicotine intake lead to reduced reward despite increased dopamine release in smokers?
• A patient with hypertension has unusually low plasma renin activity. What distinguishes primary hyperaldosteronism (Conn's syndrome) from secondary hyperaldosteronism in this patient?
• Why does plaque buildup in arteries increase distal blood pressure variability more than proximal?
• Why does replicative senescence occur in human somatic cells with each division, leading to increased susceptibility to age-related diseases?