What is obligatory water reabsorption quizlet?
Obligatory water reabsorption is when aquaporins are always present regardless of the state of hydration and facultative reabsorption is when the aquaporins are present only with ADH. Explain the hormonal mechanisms that control sodium and water reabsorption in the distal convoluted tubules and collecting ducts.
Where does obligatory water reabsorption occur?
The correct answer: Obligatory water reabsorption takes place in proximal convoluted tubule.
Which of the following is involved in obligatory water reabsorption?
Water reabsorption by the kidney requires the presence in the nephron epithelium of water channels—aquaporins—which are present in the apical and basolateral membranes of the tubule cells, and are responsible for the ‘obligatory’ water reabsorption of the proximal tubule, and the ‘facultative absorption’ (under the …
What is the reabsorption of water?
Water reabsorption is by osmosis through water channels in the membrane. These water channels consist of a family of proteins called aquaporin. At least seven different aquaporin isoforms are expressed in the kidney.
What is meant by mandatory reabsorption?
The reabsorption of water in the earlier parts of the nephron (regardless of a person’s state of hydration), independent of ADH is termed as ‘obligatory reabsorption of water’, whereas the water reabsorption in the distal part of the nephron (in accordance with the body’s state of hydration), under the influence of ADH …
What is the difference between obligatory water reabsorption and facultative water reabsorption?
Explanation: Water reabsorption together with solutes in tubular fluid is called obligatory water reabsorption. Reabsorption of the final water, facultative reabsorption, is based on need and occurs in the collecting ducts and is regulated by ADH.
What is reabsorbed by the kidney?
Most of the reabsorption of solutes necessary for normal body function such as amino acids, glucose, and salts takes place in the proximal part of the tubule. This reabsorption may be active, as in the case of glucose, amino acids, and peptides, whereas water, chloride, and other ions are passively reabsorbed.
What is absorbed in the distal convoluted tubule?
Early Distal Convoluted Tubule The role of the early DCT is the absorption of ions, including sodium, chloride and calcium. It is impermeable to water.
What is obligatory water loss?
The minimal amount of fluid loss from the body that can occur is referred to as the obligatory water loss. This sets a figure for the minimal amount of fluid intake that is required to maintain total water balance.
What do you mean by reabsorption?
Definition of reabsorption : the act or process of absorbing something again or of being absorbed again sodium reabsorption during sweating reabsorption of light drugs blocking reabsorption of serotonin by nerve endings.
What is reabsorption in the kidney?
In renal physiology, reabsorption or tubular reabsorption is the process by which the nephron removes water and solutes from the tubular fluid (pre-urine) and returns them to the circulating blood.
Which part of the renal tubule is the site of obligatory water reabsorption only?
proximal convoluted tubule
The proximal convoluted tubule is where a majority of reabsorption occurs. About 67 percent of the water, Na+, and K+ entering the nephron is reabsorbed in the proximal convoluted tubule and returned to the circulation.