When water intake is low, spinal cells in the brain signal the pituitary to release

a. epinephrine.

b. antidiuretic hormone.

c. thyroxin.

d. insulin.?

When water intake is low, spinal cells in the brain signal the pituitary to release B. antidiuretic hormone.

Antidiuretic hormone, also known as ADH, exists in all mammals and is responsible for the retention of water in the body, as well as the constriction of blood vessels. Since there is not a lot of water in the body, ADH is activated to retain what little water there is.