Water and major minerals Flashcards
what are the five functions of sodium?
cation of extracellular fluid, regulator of volume, acid base volume, nerve transmission, muscle contraction
what do fluids maintain and what does it influence?
Fluids maintain blood volume, which influences blood pressure (BP)
what are there three steps of the nephron?
- blood flows into the glomerulus and some of its fluid with dissolved substances is absorbed into the tubule
- the fluid and substances needed by the body are returned through the vessels alongside the tubule
- the tubule passes waster down into the bladder
what does vasopressin/adh respond to?
if blood volume or BP too low or extracellular fluid too concentrated
what does the hypothalamus signal the pituitary to release in BV or BP too low?
ADH which triggers thirst
what does renin respond to?
if blood pressure is too low
what does renin do?
Raises blood volume and BP
what is angiotensin?
Hormone involved in BP regulation that acts as a vasoconstrictor
what does renin hydrolyze?
Renin hydrolyzes angiotensinogen (blood protein) to angiotensin I
how does angiotensin increase BP?
Another enzyme, angiotensin-converting enzyme, converts angiotensin I to angiotensin II resulting in increased BP
what does angiotensin stimulate?
Angiotensin stimulates the release of aldosterone from the adrenal glands
what does aldosterone signal?
Aldosterone signals kidneys to excrete more K & retain more Na & therefore H20
what is mEq?
mEq – concentration of electrolytes in a volume of solution
what do electrolytes attract?
Electrolytes attract H20
what is osmosis?
Movement of H20 across membrane toward the side where the solutes are more concentrated.
what do ions regulate?
Ions regulate pH of bodily fluids—pH: measure of H+ ion concentration
what are buffers?
substances that keep a solution’s pH constant when acids or bases are added
what happens in the lungs if carbonic acid is too great?
If carbonic acid is too great increased respiration more C02 exhaled
what happens in the lungs if bicarbonate too great?
If bicarbonate too great slowed respiration more C02 retained forming more carbonic acid
what is the AI for NA?
1500
what is the DASH diet?
Low in saturated fat, trans fat and total fat.
low in sodium
high in calcium, potassium and magnesium
what does the dash diet do over time?
Reduces BP in short time
what happens with high NA intake?
increased calcium excretion
what are the two symptoms of Na toxicity?
edema and HTN
what does Cl do?
maintains fluid and electrolyte balance
what is the AI for Cl?
2300 mg
what is the symptoms of chloride toxicity?
vomiting
what are the four functions of potassium?
Maintenance of fluid & electrolyte balance
Cell integrity
Nerve transmission
Muscle contraction
Heartbeat
what is the AI for potassium?
AI = 4700 mg for adults
what does a decrease in potassium in a diet result in?
HTN & increase risk of heart disease
what do potassium rich foods reduce the risk of?
K+ rich foods reduce risk of stroke
what is potassium deficiency the most common ?
Most common electrolyte imbalance
symptoms of potassium deficiency?
Results in HTN, salt sensitivity, kidney stones and bone turnover.
calcium is the most what in the body and where is it found?
Most abundant mineral in body
99% in bones & teeth
the one percent of calcium in body fluids does what?
Blood pressure maintenance (DASH eating plan)
Muscle contraction
what is calcitonin?
Hormone from the thyroid gland that regulates blood Ca by lowering it when levels are too high
what is the parathyroid hormone (PTH)?
Hormone from parathyroid glands that regulate blood Ca by raising it when it falls too low
Stimulates action of Vit D
what is calcium rigor?
Blood levels > normal
Muscles contract & cannot relax
Hardness or stiffness of muscles
what is calcium tetany?
Blood levels < normal
Uncontrolled muscle contraction or spasms
what is the AI for calcium for teens?
1300 mg/day for adolescents
what is the calcium AI for adults?
1000 mg/day for adults up to age 50
1200 mg/day for women over 50 and everyone over 70
how does Ca absorption increase in pregnant women?
Pregnant woman: doubled absorptio
what are the four function of phosphorous?
buffer, DNA, energy, phospholipid
where is phosphorus found?
2nd most abundant mineral in body
85% bound with Ca in bones & teeth
what is phosphorous RDA?
700 mg/day
what does magnesium inhibit?
Muscle contractions
Blood clotting
what are the functions of magnesium?
Bone health
Energy metabolism
Aids in making proteins
Enzyme systems
ATP metabolism
where is Mg found?
> ½ in bones
Reservoir for blood Mg
Remainder in muscles and soft tissue
1% extracellular fluid
what are the symptoms of Mg deficiency?
tetany, impaired CNS, dysphagia, growth failure
what are the three symptoms of Mg toxicity?
Diarrhea
Alkalosis
Dehydration
Mg RDA for men?
400mg
Mg RDA for women?
310 mg/day
what are the functions of sulfate?
Determines contour of protein molecules
Disulfide bridges
Skin, hair, nails
