Excretion in humans：練習題

Which sequence of structures correctly describes the flow of urine through the human urinary system starting from where it is produced?

Why is the process of excretion considered essential for the survival of a human?

In the human kidney, which process is primarily responsible for ensuring that glucose is not present in the urine of a healthy individual?

During a laboratory analysis, the concentration of various substances in the renal artery and renal vein were compared. Which result would be expected for a healthy kidney?

Which components are typically found in the urine of a healthy person?

State the two primary waste products excreted by the kidneys and explain the functional difference between the ureter and the urethra in the human body.
Note: Consider the source of the waste and the pathway of excretion.

A person is diagnosed with a condition where the glomerulus is unusually permeable. Predict and explain the effect this would have on the concentration of protein in the urine compared to a healthy individual.

Describe the role of the liver in the assimilation of amino acids and state the name of the process that removes the nitrogen-containing part of excess amino acids to form urea.

(a) State two substances, other than urea, that are excreted by the kidneys when they are in excess of the body's requirements.

(b) Describe the differences in composition between the renal artery and the renal vein regarding the concentration of urea and oxygen.

(c) Although the kidneys are primary excretory organs, the lungs also perform excretion. Identify the waste product excreted by the lungs and describe the process by which it leaves the blood to enter the alveoli.

(a) The liver plays a vital role in the processing of nutrient molecules. Describe how the liver is involved in the assimilation of amino acids.

(b) When there is an excess of amino acids in the body, the liver performs a process called deamination.
(i) Describe the process of deamination.
(ii) Identify the part of the amino acid molecule that is removed to form urea.

(c) Trace the route taken by a molecule of urea from the time it leaves the liver until it enters the kidney, naming the main blood vessels involved.