Disorders of Water Balance Flashcards
a hypertonic environment has what effect on ADH levels
- increases ADH levels
what does ADH release cause
- increased tubular reabsorption of water
after the body fluid has been diluted and is now isotonic, what happens to ADH release and thirst reflex
- inhibition of ADH release
- inhibition of thirst
maximally dilute urine has what osmolality
- 50-100
maximally dilute urine occurs under what conditions
- large water intake
- no ADH
maximally concentrated urine has what osmolality
- 1200
maximally concentrated urine under what condition
- low water intake
- high ADH levels
osmoreceptors respond to what signal
- high plasma osmolality
sensitivity of osmoreceptors
- highly sensitive
- respond to 1-2% change
low pressure baroreceptors respond to what signal
- decreased extracellular fluid volume
sensitivity of low pressure baroreceptors
- lowly sensitive
- respond to 5% change
high pressure baroreceptors respond to what signal
- decreased blood pressure
sensitivity of high pressure baroreceptors
- low sensitive
- respond to 5% change
direct neural receptors respond to what signals
- drugs
- vomiting
- stress
- ADH
between osmoreceptors, low pressure and high pressure baroreceptors, and direct neural receptors, which are physiologic responses
- osmoreceptors
- low pressure and high pressure baroreceptors
between pressure/volume and osmolality, which will cause greater release of ADH
- pressure/volume trumps osmolality
ICF is estimated by calculating
- effective osmolality
ICF is proportional to
- 1/effective osmolality
sodium concentration is equal to
- H2O balance
ECF is estimated by
- physical examination
what parts of the physical exam would lead you to think increased ECF
- edema
- crackles
- elevated JVP
what parts of the physical exam would lead you to think decreased ECF
- low BP
- increased pulse
- decreased capillary refill
- no edema
ECF volume =
Na+ balance