SF: Chapter 27pt2

What are the 6 essential electrolytes

1. potassium

2. phosphate

3. calcium

4. chloride

5. magnesium

6. sodium

What are 5 important functions of electrolytes in our bodies

1. balance blood pH levels

2. facilitate waste excretion from cells

3. maintain fluid balance

4. promote proper functioning of heart, nerve, muscle, and brain cells

5. transport nutrients into cells

electrolytes def.

chemical compounds that dissociate into ions in water due to the ions being charged particles but losing their conduct electrical currents

what are the 3 general categories of electrolytes

1. inorganic salts

2. inorganic/organic acids and bases

3. some proteins

do electrolytes have an increased or decreased osmotic power

increased due to dissociation into 2+ ions

what ions do electrolytes dissociate into

NaCl (2)

MgCl2 (3)

osmosis def.

fluid shift of water from lesser osmolality to higher osmolality

where do we get most of our major extracellular ions from

food and water we ingest

how do we primarily remove the major extracellular ions from our bodies? (organs)

kidneys!!!, liver, skin, lungs

ex of literal ways to remove ions from body

urine, feces, sweat, vomit

when does the concentration of electrolytes change

growth, weight gain or loss

our electrolyte balance is equivalent to

salt balance

roles of electrolytes in the body (4)

1. control fluid movements

2. provide minerals for excitability

3. secretory activity

4. membrane permeability

What is the most abundant cation in the body

sodium

What is the primary role of sodium?

control ECF volume and water distribution

What will always follow NaCl

water

What is the content of Na+

total amount of Na+ in the body determines ECF volume and BP

Does low blood pressure increase or decrease Na+ / ECF

increase both

Does high blood pressure increase or decrease Na+ / ECF

decrease both

does an activated RAAS system increase or decrease Na+ and ECF

increase both

Does an increase in water retention and intake increase or decrease Na+ /ECF

increase ECF; decrease Na+

hyponatremia def.

overdilution of blood due to excess water consumed after exercising

what can hyponatremia lead to

mental confusion, seizures, coma

What can solute loss and water retention related to hyponatremia be caused by

vomit, diarrhea, burned skin, excessive diarrhea

What can water AND solute loss cause

decreased BV/BP = circulatory shock

hypernatremia is due to?

excessive aldosterone secretion that leads to pulmonary edema and muscle convulsions

What else can hypernatremia be caused by

dehydration

what does hypernatremia cause?

thirst, confusion, lethargy, coma

What is the predominant anion of the ECF

chloride

How do we regulate chloride

with Na+

with acidosis, how do we restore blood pH to normal

less Cl- w/ Na+ due to bicarbonate ion reabsorption

hypochloremia is caused by

excessive sweating/diuresis/vomit/diarrhea

What can cause excessive retention of chloride

low salt intake or SIADH

What could hypochloremia be indicative of

heart failure or addison's disease

hyperchloremia is indicative of

dehydration, cushing's syndrome (high blood Na+), kidney disease

What is the chief intracellular cation

Potassium

why is potassium tightly regulated

it is critical in determining RMP for electrically excitable cells

potassium plays a role in???

depolarization and hyperpolarization

elevated potassium: secrete or store aldosterone?

secrete

What does the secretion of aldosterone by K+ cause?

increase in Na+ reabsorption and K+ secretion

Where does aldosterone act on sodium

Na+/K+ pump in DCT

What is hypokalemia due to

excess K+ secretion due to elevation of aldosterone and insulin

in hypokalemia, what causes the initial excessive elevation of aldosterone

water pills/diuretics

symptoms of hypokalemia

fatigue, muscle cramps or temporary paralysis

hyperkalemia is due to?

renal disease causing less renal excretions

symptoms of hyperkalemia

intestinal cramping, diarrhea, temporary paralysis

calcium plays a role in?

exocytosis, muscle contraction, regulates ap in cardiac muscle, blood clotting

What are the 3 sites for ECF calcium regulation

1. kidneys

2. GI tract

3. bones

where are we going to find 99% of our body's calcium

bone

How do we regulate calcium?

deposit stores of calcium into the bone then reabsorb it when needed

how do we regulate calcium more-long term?

maintaining balance between absorption across intestinal wall and excreted by the kidneys

Calcium is regulated by what 3 hormones

PTH, vitD, calcitonin

PTH function

increases blood calcium via osteoclasts, renal tubule resorption, VitD3 absorbed in small intestine

Calcitonin (c cells) function

decrease blood calcium, inhibits osteoclasts to prevent bone breakdown

hypocalcemia effects what?

pm permeability to sodium causing nerve and muscle tissue to spontaneously create action potentials

what does hypocalcemia ultimately cause

muscle tetany

What does hypercalcemia prevent

depolarization of nerve and muscle cells

hypercalcemia deposits??? which causes??

CaCO3 salts in soft tissue which causes irritation and inflammation

what can hypercalcemia ultimately lead to

cardiac arrhythmias

where do we find 85% of our body's phosphate

bone, teeth, cells

roles of phosphate (4)

1. bind to lipids, proteins, and carbs

2. component in DNA, RNA, and ATP

3. regulate enzyme activity

4. acts as a buffer

what causes hypophosphatemia

vitD deficiency and alcohol abuse

what causes hyperphosphatemia

1. acute and chronic renal failure due to decreased filtrate by kidneys

2. chronic laxative use

where do we store magnesium

bones or ICF

which is more rare: hypomagnesemia vs hypermagnesemia

hypermagnesemia

hypomagnesemia is due to

alcohol abuse

What can hypomagnesemia cause

muscle weakness, muscle convulsions, insulin resistance, chronic diarrhea, severe malnutrition, diuretic therapy, cramps

hypermagnesemia is due to

renal failure, chronic laxative use, excessive ingestion of antacids/Mg intake

what can hypermagnesemia cause

nausea, hypotension, low RR, calcium phosphate deposit in joints, lungs, kidneys

consequences of hypermagnesemia

lethargy, impaired CNS functioning, coma, respiratory depression, cardiac arrest