The structure labeled can be influenced by hormones to change the concentration of the urine.

The diagram attached is known as the nephron,it is labelled from A to E, the structure labelled E which is known as the COLLECTING DUCT can be influenced by hormones to change the concentration of urine.

Explanation: Antidiuretic hormone ADH is one of the hormones that is produced by the anterior lobe of the pituitary gland of the endocrine system,this antidiuretic hormone performs certain functions of which one is that it helps to increase the rate and amount of water that is reabasorbed in the distal convulated tubule of the nephron during the second stage of urine formation,when these water are reabsorbed,the urine being produced becomes more concentrated and there is a further reduction in the volume/quantity of urine produced.

When this volume of urine is decreased/reduced, plasma osmolarity increases in reaction to the decreased volume of urine.

Urine are also reabsorbed in the collecting duct.

igneous rocks which formed by the crystallization of magma at the surface of the earth called extrusive rocks. they are characterized by fine-grained textures because the rapid cooling at or near the surface did not provide enough time for large crystals to grow.