A 48-year-old man presents with severe hemorrhage following a motor vehicle collision. Vital signs show BP 85/52, HR 118, RR 22, SpO2 98% on room air. Serum creatinine is 2.1 mg/dL with BUN 48 mg/dL. Urinalysis shows muddy brown casts. He denies previous kidney disease. Which renal cells directly synthesize and release renin in response to the decreased renal perfusion pressure from his acute blood loss?
- A)Podocytes lining the visceral Bowman capsule
- B)Mesangial cells of the glomerulus
- C)Alpha intercalated cells of the collecting duct
- D)Juxtaglomerular granular cells of the afferent arterioleGABARITO
- E)Macula densa cells of the distal tubule
Explicação
Renin is released by juxtaglomerular granular cells, which are modified smooth muscle cells in the wall of the afferent arteriole. Hemorrhage lowers renal perfusion and stimulates these cells through baroreceptor and sympathetic mechanisms. Ver explicação completa e trilha adaptativa →