Anatomy & Physiology Genitourinary #9

Question

Which step in the process of urine production comes immediately before the excretion of urine from the body?

Answers

  1. The filtration of blood.
    • Rationale:

      The filtration of blood is the second step in the formation of urine. It does not occur immediately before the excretion of urine from the body.

  2. The secretion into the blood.
    • Rationale:

      Secretion into the blood is the step that occurs immediately before the excretion of urine from the body. This allows substances that are not waste products to re-enter circulation before the excretion of urine (a waste product) occurs.

  3. The production of ultrafiltrate.
    • Rationale:

      The production of ultrafiltrate is the third step in the formation of urine. It does not occur immediately before the excretion of urine from the body.

  4. The reabsorption from the blood.
    • Rationale:

      Reabsorption from the blood is the fourth step in the formation of urine. It does not occur immediately before the excretion of urine from the body.

Overview

There are three main processes that occur within the body in order for urine formation to occur. These processes include glomerular filtration, reabsorption, and secretion.

Explanation

Learning Outcomes

The process of urine production occurs in a sequential order. The order of urine production is as follows: (1) Blood enters into the kidneys by circulation; (2) Blood filtration; (3) Production of ultrafiltrate; (4) Blood reabsorption; (5) Secretion into the blood; (6) Excretion of urine from the body. These processes ensure that waste products, and excess water, are removed from the body. At the same time, this process also guarantees the reabsorption of needed chemicals to maintain homeostasis.

Test Taking Tip

Consider the specific order of events that must occur in urine production to correctly answer this question.

Video Rationale