osmoregulation: Flashcards
What is the word to describe if the blood has too low of a water potential?
= hypertonic
What is blood with a too high water potential called?
= hypotonic
How does blood with a too low water potential occur?
= too much sweating
= not drinking enough water
= lots of ions in diet- lots of salto
How is blood with a too high water potential take place?
= drinking too much water
= not enough salt in diet
=
What is the corrective mechanism for too little water potential in the blood?
=more water is reabsorbed by osmosis, into the blood from the tubes of the nephrons
= urine is more concentrated, as less water is lost
What is the corrective method if the blood has a too high water potential?
= less water is reabsorbed by osmosis, into the blood from the tubles of the nephrons
= means urine is more dilute and more water is lost in the urine
What detects changes in water potential in the blood?
= detected by osmoreceptors, found in the hypothalamus,
= if water potential of the blood is too low, water leaves the osmoreceptors into blood , by osmosis and shrivels
= stimulates hypothalamus to to produce more hormone ADH, posterior pituitary
= if water potential of blood is too high, water enters osmoreceptors by osmosis from the blood, stimulates hypothalamus to produce less ADH
Where does ADH move from?
- moes to posterior pituarty, released into capilairies and into the blood
= ADH travels through the blood, to target organ the kidney
=
How does ADH work?
= when ADH reaches the kidney, causes an increase in permeability, of the walls of the collecting duct, and distal convuluted tube
= this means more water leaves the nephron, and is reabsorbed into the blood, so urine is more concentrated
What are aqua porins?
= receptors on the cell surface membrane on DCT, and collecting duct where ADH binds to
= when bound it activates a phosphporylase, enzyme in the cells
= causes the vesicles containing the aqua porins, ro fuse with the membrane and aquporins embedded
= aqua porins are protein channels that allow water to pass through, wit more awua porins in the cell membrane, more water leaves the DCT collecting tube and reabsorbed into the blood
If the urine is more concentrated what is the volume?
= smaller volume
= less water is lost in urine
If the urine is less concentrated whatis the volume
= larger volume
= mpre water is lost as urine