Which of the following is not a process involved with the excretory (urinary) system?
A. carbonic anhydrase converting carbon dioxide to carbonic acid in red blood cells
B. blood pressure forcing substances like urea out of capillaries into the nephron
C. secretion of toxins ions out of blood at the distal tubule
D. the hormone ADH causing increased reabsorption of water from the filtrate
To determine which of the processes is not involved with the excretory (urinary) system, let's go through each option and explain its connection to the system.
A. Carbonic anhydrase converting carbon dioxide to carbonic acid in red blood cells:
This process is involved in the respiratory system, where carbon dioxide produced by cells diffuses into the capillaries and is carried by red blood cells. Carbonic anhydrase is an enzyme that catalyzes the conversion of carbon dioxide to carbonic acid, which then dissociates into hydrogen ions and bicarbonate ions. This process helps maintain pH balance in the body but is not directly related to the urinary/excretory system.
B. Blood pressure forcing substances like urea out of capillaries into the nephron:
This process is an essential step in the urinary/excretory system. Blood pressure in the glomerular capillaries helps to filter waste products, such as urea, out of the blood and into the nephron, which is the functional unit of the kidney. The filtered substances then continue through the nephron to be processed and eventually excreted as urine.
C. Secretion of toxin ions out of blood at the distal tubule:
This process is also crucial in the urinary/excretory system. The distal tubule of the nephron plays a role in the selective reabsorption and secretion of ions and other substances to maintain electrolyte balance and eliminate toxins from the body. Secretion refers to the active transport of specific ions, drugs, and other substances from the blood into the tubule for eventual excretion.
D. The hormone ADH causing increased reabsorption of water from the filtrate:
This process is regulated by the endocrine system and is connected to the urinary/excretory system. ADH (antidiuretic hormone), also known as vasopressin, is produced by the hypothalamus and released from the posterior pituitary gland. It acts on the collecting ducts of the nephron, promoting increased reabsorption of water from the filtrate back into the blood. This controls the body's water balance and helps concentrate urine.
Therefore, after understanding each process, the option that is not involved with the excretory (urinary) system is:
A. Carbonic anhydrase converting carbon dioxide to carbonic acid in red blood cells.