Which mechanism reduces oxygen transfer across the placenta in preeclampsia?

💡 Explanation

Increased placental vascular constriction restricts maternal intervillous blood flow, reducing oxygen delivery because placental vascular resistance reduces the area available for diffusion. Therefore increased resistance impairs transport, rather than altered Hb or unrelated proximal kidney filtration rate, limiting nutrients.

• A marathon runner collapses mid-race on a hot day, exhibiting disorientation and cessation of sweating. Why does cessation of sweat contribute to this athlete's hyperthermia?
• If a patient consistently excretes highly concentrated urine with elevated calcium oxalate levels despite normal fluid intake, which consequence relating to renal function is most likely?
• Why does hyperthermia accelerate exponentially once the body's core temperature surpasses 41°C, even if the external temperature remains constant?
• Why does the liver sometimes fail to properly digest fats following gallbladder removal?
• If a patient with iodine deficiency receives a fixed dose of exogenous T4, which consequence follows regarding T3 production?
• If a genetically predisposed individual is repeatedly exposed to an allergen such as bee venom, which consequence is most likely due to mast cell degranulation?