Control of Blood Water Potential Flashcards
Why is the control of blood water potential important?
It is crucial for maintaining the balance of water in and out of cells, preventing them from becoming too swollen (lysis) or too shriveled (crenation), which can damage tissues and organs.
What is blood water potential?
Blood water potential refers to the potential energy of water in the blood, determined by the concentration of solutes (such as ions and glucose) and pressure.
What happens if blood water potential is too low?
If blood water potential is too low (more negative), it means there are too many solutes in the blood, leading to water moving out of cells, causing them to shrink (crenation).
What happens if blood water potential is too high?
If blood water potential is too high (less negative), it means there are fewer solutes in the blood, causing water to move into cells, potentially leading to swelling or lysis.
How is blood water potential controlled?
Blood water potential is controlled by the kidneys, which regulate the amount of water and solutes in the blood through processes like filtration, reabsorption, and secretion.
What is the role of the kidneys in controlling blood water potential?
The kidneys filter blood to remove waste products and excess water, adjusting the water potential by reabsorbing water into the bloodstream or excreting it as urine.
What is antidiuretic hormone (ADH) and how does it regulate blood water potential?
ADH is a hormone released from the pituitary gland in response to high blood solute concentration. It increases water reabsorption in the kidneys by making the walls of the collecting ducts more permeable to water.
How does ADH affect the kidney’s collecting ducts?
ADH binds to receptors on the collecting ducts in the kidneys, triggering the insertion of aquaporin channels into the membrane, allowing more water to be reabsorbed into the bloodstream.
What happens when blood water potential is too high?
When blood water potential is too high, ADH release is suppressed, leading to less water reabsorption and the production of more dilute urine to restore water balance.
How does the negative feedback mechanism work in controlling blood water potential?
Negative feedback maintains homeostasis by detecting changes in blood water potential and adjusting hormone levels (such as ADH) to counteract the change and restore balance.
What is osmoregulation?
Osmoregulation is the process of regulating the balance of water and solutes in the blood to maintain a constant blood water potential.
How does the hypothalamus contribute to osmoregulation?
The hypothalamus monitors blood water potential. When it detects high solute concentrations, it stimulates the release of ADH from the pituitary gland to conserve water.
What is the role of the medulla in the kidneys?
The medulla in the kidneys contains the loops of Henle, which create a concentration gradient in the kidney tissue, aiding in the reabsorption of water from the filtrate.
How does the loop of Henle contribute to water reabsorption?
The loop of Henle creates a concentration gradient in the medulla of the kidney, which allows for the reabsorption of water from the filtrate in the collecting ducts.
What is the role of the proximal convoluted tubule in regulating water potential?
The proximal convoluted tubule reabsorbs most of the water and solutes from the filtrate, including glucose, amino acids, and sodium ions, contributing to water balance.
What is the role of the distal convoluted tubule in regulating water potential?
The distal convoluted tubule fine-tunes the reabsorption of water, and ADH regulates this process to ensure blood water potential is maintained.
What is the effect of dehydration on blood water potential?
Dehydration causes an increase in blood solute concentration, lowering blood water potential. This triggers ADH release to increase water reabsorption by the kidneys.
What is the effect of overhydration on blood water potential?
Overhydration causes a decrease in blood solute concentration, raising blood water potential. This inhibits ADH release, leading to decreased water reabsorption by the kidneys.
How does blood water potential affect the release of ADH?
When blood water potential is low (high solute concentration), ADH release increases, promoting water reabsorption. When water potential is high, ADH release decreases.
