Final answer:
The correct sequence of transport for reabsorbing Na+ in the ascending limb is sodium ions being reabsorbed in exchange for H*, followed by Na+ and Cl- exiting through ion channels, and then sodium being actively transported out of the filtrate.
Step-by-step explanation:
The correct sequence of transport for Na+ that is being reabsorbed in the ascending limb is:
- Sodium ions are reabsorbed from the filtrate in exchange for H* by an antiport mechanism in the apical membranes of cells lining the renal tubule.
- As the filtrate enters the ascending limb, Na+ and Cl- ions exit through ion channels present in the cell membrane.
- Further up, sodium is actively transported out of the filtrate, and chlorine ions follow.
The ascending loop of the kidney plays a crucial role in reabsorbing sodium ions and other solutes from the filtrate.