How does ADH affect the amount of water in the body, and how does it accomplish this? How does this affect the osmolarity of the blood?

Video transcript

Hi, everyone. Let's take a look at this practice problem together. This hormone is responsible for the osmolarity of the blood. The answer options are a thyroid hormone, B, erythropoietin C, vasopressin and D epinephrine. So, recall that osmolarity is a measure of salute concentration in blood. The solvent is water. So, osmolarity of the blood is largely due to how much water is in the blood. So which hormone affects water concentration in the blood option. A thyroid hormone recall that thyroid hormone main role is in metabolism. So option A is incorrect. Option B erythropoietin. This is a hormone that is secreted from the kidneys to stimulate red blood cell production. So, option B is also incorrect. Option D epinephrine recall that epinephrine is not only a hormone, but it can also act as a neurotransmitter and it gets the ready body ready for the fight or flight response. So some of the things it does is it increases cardiac output and increases blood glucose levels. However, it does not affect water concentration in blood. So, option D is also incorrect. The correct answer is vasopressin. This is a hormone that is secreted by the pituitary, posterior lobe and it causes water resorption in the collecting ducts of the kidneys. This prevents water excretion in the urine and increases water retention. And thus, it can influence the osmolarity of the blood. So the correct answer is option C vasopressin. All right, everyone. I hope you found this helpful and I'll see you soon for the next practice problem.