Final answer:
The distal and collecting tubules are regulated by aldosterone and ADH, which collectively help maintain the body's fluid balance and regulate blood pressure.
Step-by-step explanation:
The distal and collecting tubules in the kidneys are under the influence of two main hormones: aldosterone and antidiuretic hormone (ADH). Aldosterone, produced by the adrenal glands, increases the reabsorption of sodium ions in the distal tubules and collecting ducts, which in turn promotes water reabsorption due to osmosis, leading to an increase in blood volume and blood pressure.
ADH, released from the pituitary gland, promotes water recovery by encouraging the insertion of aquaporin water channels into the membranes of kidney cells, letting more water be reabsorbed from the filtrate back into the bloodstream. These mechanisms are part of a finely tuned system that regulates the body's fluid balance and blood pressure.