Which of the following correctly describes the role of the descending and ascending limbs of Henle's loop in concentrating and diluting the filtrate, respectively, and what makes the descending limb distinct in its permeability?
1
Descending limb: impermeable to water, concentrates filtrate; Ascending limb: permeable to electrolytes, dilutes filtrate
2
Descending limb: permeable to water, concentrates filtrate; Ascending limb: impermeable to water, dilutes filtrate
3
Descending limb: permeable to electrolytes, dilutes filtrate; Ascending limb: impermeable to electrolytes, concentrates filtrate
4
Descending limb: impermeable to electrolytes, dilutes filtrate; Ascending limb: permeable to water, concentrates filtrate