Sodium Flashcards
approx 70% of the sodium in the body is located in the,____, 30% is located_____
extracellular fluid
bone crystals
primary source of dietary sodium is
added salt in the form of NaCl
~75% of dietary sodium is from
processed foods
____ % of sodium consumed is absorbed
95-100%
absorption of sodium occurs in what three pathways
Na/glucose cotransport system
Na/Cl co transport system
electrogenic Na absorption mechanism
Sodium is transported via the
Na/K ATPase pump
the Na/K ATPase pump pumps sodium out of the ____ accoss the basolateral membrane into the blood stream
enterocyte
functions of sodium
maintenance of membrane potential
maintenance of blood volume and blood pressure
sodium is the principle _______ cation
extracellular
potssium is the principle ______ cation
intracellular
the membrane potential is maintaine by
Na/K ATPase pump
tight control of cell membrane potential is critical for
nerve impulse transmission
muscle contraction
heart function
sodium is the primary determinant of _______ volume
extracellular
in the circulatory system, baroreceptors sense changes in blood pressure and send _____ or ______ signals to nervous system and endocrine glands to affect sodium regulation by the kidneys
excitatory or inhibitory
serum sodium levels in the blood are maintained by what hormones
renin-angiotensin-aldosterone system
anti-diuretic hormone (ADH)
atrial natriuretic hormone (ANP)
in response to a significant decrease in blood vlume or pressure, the kidneys release _____ into the circulation which produces angiotension I
renin
angiotensin I is from _____ in the liver
angiotensinogen
angiotensin I is converted to angiotensin II by
Angiotensin converting enzyme (ACE)
ACE is located
on the inner surface of blood vessels
lungs
liver
kidney
Angiotensin II stimulates the ______ of arteriols
constriction
Angiotensin II is a potent stimulator of
aldosterone synthesis
aldosterone is produced by the
adrenal glands
aldosterone is a steroid hormone that acts on the _____ to increase the reabsorption of sodium and excretion of potassium
kidneys
a significant decrease in blood volume or pressure will stimulate the secretion of
ADH
ADH acts on the kidneys to do what
increase reabsorption of water
ANP is secreted by the ____
heart muscle cells
why is ANP secreted
in response to high blood volume
what does ANP do
increases the glomerular filtration rate
what happens when the glomerular filtration rate is increased
increasing the excretion of sodium and water
ANP inhibits the release of _____
renin
excess sodium is excreted by the kidneys under the control of ___
aldosterone
aldosterone is released from the
adrenal cortex
why is aldosterone released from the adrenal cortex
in response to low sodium or high potassium and promotes retention of sodium and excretion of potassium
hyponatremia may result from
inappropriate ADH secretion
severe/prolonged d/v
excessive/prolonged sweating
use of some diuretics and certain kidney dzs
Sx of hyponatremia
H/A
n/v
mm cramps
fatigue, weakness, fainting
complications of severe and rapidly developing hyponatremia include
cerebral edema seizures coma brain damage death
clinical indications for sodium supplementation
electrolyte replenishment
excessive intake os sodium chloride lead to an increase in _____fluid volume
extracellular
excessive sodium intake can cause
n/v/d
abd cramping
hypernatremia symptoms
dizzy
faining
low BP
oliguria
severe hypernatremia may result in
edema hypertension tachycardia dyspnea convulsions coma death
high ____ intake increases urinary sodium excretion and protects against the hypertensive effects of sodium
potassium
high sodium intake can increase urinary _____ excretion
calcium
