PH, Electrolyte, and Fluid Balance

Question 1

distribution of fluids in the body

Answer 1

• total body water - all fluids are 60% of body weight (your weight x .6 = lbs of water)
• intracellular fluid ICF - 2/3 total body weight (inside cells)
• extracellular fluid ECF - 1/3 total body weight
• interstitial fluid: between cells
• intravascular fluid: blood plasma in vessels
• lymph, synovial, intestinal, CSF, sweat, urine, pleural, perioteoneal, pericardial and intraocular fluids

Question 2

body’s PH

Answer 2

• 7.35-7.45
• basic
• PH = power of hydrogen. PH measures hydrogen in body

Question 3

Sodium/Chloride Balance

Answer 3

SODIUM (Na+)

• primary extracellular fluid (ECF) cation
• regulates osmotic foces
• role = fluid movement - neuromuscular irritability, acid-base balance, cellular reactions, membrane transport
• WATER always move with Na+*

CHLORIDE (Cl-)

• primary ECF anion
• provides electroneutrality

Question 4

anion

Answer 4

negatively charged ion

Question 5

cation

Answer 5

positively charged ion

Question 6

tonicity

Answer 6

change in concentration of solutes (salt) with relation to solvent (water)

• isotonic: ECF = 0.9% NaCl
• hypertonic - ECF >0.9% NaCl. cells SHRINK. more solutes outside of cell than in. H2O moves out of cell with Na+
• Hypotonic - ECF <0.9% NaCL. cells SWELL. more solute into cell. can cause cells to lyse.

Question 7

Sodium Na+

Answer 7

• regulation of fluid balance - VERY important electrolyte
• most abundant positive ion (cation)
• 90% ECF cations
• Hypernatremia: more na+ outside of cell ECF
• Hyponatremia: less na+ outside the cell ECF

Question 8

Hypernatremia

Answer 8

• dehydration - pulls water out of cell
• more Na+ than water
• intracellular dehydration, hypertension (hypervolemic = higher volume of blood)
• H20 movement from ICF to ECF (interstitial)
• Causes: diabetes, diarrhea
• manifestations: increased cellular functioning - convulsions, thirst, fever, muscle twitching, hyperreflexia

Question 9

hyponatremia

Answer 9

• less Na+ and more H20
• decreased BP, decreased cell fun
• Casues: vomiting, diarrhea, GI scution, burns, diuretics
• manifestations: decreased functioning - lethargy, confusion, depressed reflexes, seizures, coma, hypotension, tachycardia, decreased urine output

Question 10

chloride Cl-

Answer 10

• primary ECF anion
• electroneutrality with Na+
• Hypochloremia: result of hyponatremia or increased HC03
• vomiting = loss of hydrochloric acid = loss of Cl- in blood
• cystic fibrosis: imbalance of Na+ and Cl- transport across epithelium

Question 11

potassium K+

Answer 11

• major intracellular electrolyte 98% intracellular, Na/k ATPase Pump
• affects resting membrane potential
• transmission and conduction of nerve impulses, normal cardiac rhythm, skeletal and smooth muscle contractions, “action potentials”

Question 12

K+ and PH

Answer 12

• change in PH greatly affects k+ balance
• acidosis causes: increase in H+ inside cell -> k+ moves out of the cell
• more H+ outside cell –> H+moves into cell –> k+ is pulled out
• acidosis = hyperkalemia
• Alkolosis causes: decrease in H+ inside cell –> k+ into cell
• increased PH in tissue and blood pushes K+ into cell
• alkalosis = hypokalemia

Question 13

hypokalemia

Answer 13

• harder to start and action potential with low K+
• lower resting membrane potential = less excitable cell
• low K+ outside of cell
• Causes: low intake of k+, increased loss of K+, increased K+ flow into cell
• manifestations: heart cells are less excitable, weakness, atrophy, cardiac dysrhythmias,
• decresed K+ causes decreased rest membrane potential causes decreased heart function

Question 14

hyperkalemia

Answer 14

• increased k+ outside cell = increased excitability
• increased resting membrane potential
• causes: increased shift from ICF (acidosis), decreased renal excretion
  manifestations:
• mild heart attacks = increased neuromuscular irritability/activity. tingling of lips & fingers, restlessness, intestinal cramps/diarrhea
• severe attacks = no repolarization = muscle weakness, decreased tone, flaccid paralysis, cardiac dysrhythmias, PVCs

Question 15

big picture of electrolytes

Answer 15

• low K+ = decreased excitability. Bradycardia, asystole
• high K+ = increased excitability. cardiac dysrhythmias, PVC
• low Ca+ = increased muscle excitability, decreased threshold, cramps, twitches
• High Ca+ = decreased muscle excitability, increased threshold, less excitable

Question 16

calcium Ca+

Answer 16

• needed for bone, teeth, blood clotting, muscle contractions, neurotransmitter release, hormone secretion, cell receptor function 99% in bone
• affects THRESHOLD potential
• Hypocalcemia = decreased block of Na into cell
• increased neuromuscular excitability
• decreased threshold means more excitable
• increased muscle function
• Hypercalcemia = increased block of Na into cell = decreased neurotransmitter excitability
• increased threshold potential = less excitable
• muscle weakness, cardiac arrest, kidney stones, constipation
• decreased muscle function

Question 17

fluid balance

Answer 17

sodium, calcium, and water regulation

• primarily regulated by kidneys and hormones
• water
• hypothalamus –> posterior pituitary –> ADH (antidiuretic hormone - tells kidneys to reabsorb more water out of urine)
• Na/Cl
• adrenal gland –> aldosterone
• atrial muscle –> naturetic hormones (ANH)
• aldosterone = reabsorbs na+ in kidney (H20 goes with it), causes decreased urine, increased BP
• naturetic hormone = increases urine, decreases BP. antagonistic to Aldosterone. puts more na+ and H20 into urine

Question 18

ADH Functions

Answer 18

Antidiuretic Hormone
decreased circulating fluid volume –> increased thirst & ADH secretion –> increased fluid intake and decreased water excretion –> increased renal water retention –> increased circulating fluid –> decreased plasma osmolality –> decreased ADH and decreased thirst

Question 19

RAAS Pathway

Answer 19

• release of renin causes release of aldosterone
• renin-angiotensin-aldosterone system
• a hormone system that regulates blood pressure and water (fluid) balance
• sodium balance in kidneys

Question 20

naturetic hormone

Answer 20

ANH
increase in total body na+ –> increased drinking, osmotic shift of water out of cells –> increased plasma volume –> increased atrial stretching detected by atrial endocrine cells –> ANH releases –> GFR (filtration rate) increases, decrease renin angiotensin-aldosterone, decreased na+ absorption

Question 21

balance of fluids

Answer 21

metabolism: glucose (eat) + O2 (breath) = CO2 + H2) + ATP

INTAKE: metabolism (400, produces fluid for us), food (500), drinking (1500)

OUTPUT: faeces (100), skin (400, sweat), breathing (400, water releases), urine (1500)

Question 22

fluid “tug of war”

Answer 22

HYDROSTATIC PRESSURE: pushing force

• move from high to low
• fluid pressure = BP

ONCOTIC/OSMOTIC: pulling force

• driven by proteins or electrolytes
• electrolytes pull water into cell
• plasma proteins are negatively charged

Question 23

fluid movement between ICF and ECF

Answer 23

• water, nutrients, and waste products
  between capillaries and interstitial space
• CHP + IFOP - work together
• COP + IFHP - work together
• CHD + IFOP > COP + IFHP = blood from caps into IF
• CHD + IFOP < COP + IFHP = blood from IF into caps

1. Capillary Hydrostatic Pressure
   - strongest
   - PUSH from capillaries into interstitial fluid
   - blood pressure = fluid out
2. Capillary Oncotic Pressure
   - PULL from intersistial fluid into capillaries
   - water attract to plasma proteins (albumin) = fluid in
3. Interstitial hydrostatic pressure
   - PUSH from IF fluid into caps = fluid in
4. interstitial oncotic pressure
   - weakest
   - PULL into IF fluid
   - water attraction to interstitial proteins = fluid out

• obligatory load: 10% of fluid in tissues cannot be reabsorbed into blood. COP isn’t as strong as CHP. IF Fluid drained by lymphoma

Question 24

Edema

Answer 24

excessive accumulation of fluids in interstitial space

4 major causes:

1. increased capillary hydrostatic pressure
   - increased BP = increased edema
   - venous obstruction (DVT, hepatic obstruction), salt and water retention (heart, renal failure, hypertension)
2. decreased plasma oncotic pressure
   - decreased albumin (water soluble protein) - liver disease, malnutrition, kidney disease, burns, hemorrhage
   - decreased albumin = increased edema
3. increased capillary permeability
   - trauma, burns, neoplastic (tumorous), and allergic reactions
   - increased inflammation = increased edema
4. lymph obstruction
   - removal of nodes (surgery), inflammation or tumors
   - 10% of fluid builds up in IF = edema

Question 25

PH

Answer 25

``` power of hydrogen 0-14 0 = acidi 14 = basic 7 = neutral 7.4 = bio neutral 7.35-7.45 (basic) each numberic goes up by 10X the PH range of life 6.8-7.8 acidic = hyperkalemia basic = hypokalemia ```

Question 26

acids

Answer 26

formed as end products of protein, carb and fat metabolism - major regulatory organs; bone, LUNG, KIDNEYS< blood - hydrochloric acid, carbonic acid - BIcarbonate (HCO3) carries CO2 and blood buffer

Question 27

body acids

Answer 27

two forms: VOLATILE: H2CO3 - gaseous and airborn, CO2, lungs NONVOLATILE: eliminated by kidneys, sulfuric, phosphoric

Question 28

2 most important regulatory systems for fluid, electrolyte and PH balance?

Answer 28

LUNGS: C02 blows off acid, regulates acidity KIDNEYS: biarbonate HC03 and H+ ions. * low blood PH = academy * general acidity = acidosis * high Blood PH = alkalemia * general high PH = alkalosis

Question 29

metabolic acidosis

Answer 29

kidneys retain H+ and rids too much bicarb | - low body PH

Question 30

metabolic alkalosis

Answer 30

retain more bicarb and rid H+ | - high body PH

Question 31

respiratory acidosis

Answer 31

hypoventilation | - not expelling enough CO2 (acid)

Question 32

respiratory alkalosis

Answer 32

- blowing off too much CO2 (acid) | - hypervntilation

Question 33

buffer

Answer 33

* any substance that doesn't allow a drastic change in PH. a chemical that binds excess H+ or OH- without any significant change in PH 1. 1st line = chemical buffer = BLOOD - immediate - bicarbonate buffer system - phosphate buffer system - protein buffer system 2. 2nd line = LUNGS - physiological buffer - minutes - respiratory response system 3. 3rd line = KIDNEYS = physiologic - hours - H+ and Bicarb - renal response system * compensation - PROTEINS also work as a buffer and PHOSPHATE - best blood buffer is a mix of C02 and Bicarb

Question 34

acidosis

Answer 34

- too much CO2 or too little HCO3 - lower PH 1. CO2 increases with hypoventilation (pneumonia, emphysema) 2. Metabolic conditions = ketoacidosis due to access fat metabolism (diabetes mellitus) which will lower bicarb * too much CO2 = issue with lungs * too little HCO3 - issue with kidneys

Question 35

alkalosis

Answer 35

- too much HCO3 or too little CO2 - higher PH 1. Co2 decrease via hyperventilation (respiration blows off co2) 2. Emesis (vomiting) removes stomach acid and raises bicarb * too little CO2 * too much HCO3

Question 36

compensation

Answer 36

1. if kidneys aren't working - respiratory compenstates by increasing or decreasing CO2 2. if lungs aren't working - kidneys compensate by increasing or decreasing acidity/alkalinity of urine

Question 37

metabolic acidosis

Answer 37

* kidneys retain too much H+ or secrete too much bicarb - hyperkalemia - increased respirations - hyperventilations - acidic fruity breath - causes: severe diarrhea, renal failure, shock

Question 38

metabolic alkalosis

Answer 38

* decreased acid or increased base - decreased respirations, hypoventilation - hypokalemia - causes: vomiting, diruretics

Question 39

respiratory acidosis

Answer 39

* retention of CO2 by lungs - hypoventilation, hypoxia rapid, shallow respirations - hyperkalemia - causes: pneumonia, COPD, atelectasis

Question 40

respiratory alkalosis

Answer 40

* increased loss of CO2 from lungs - increased respirations, hyperventilation - hypokalemia - causes: hypoventilation (anxiety, fear), mechanical ventilation

Question 41

normal values

Answer 41

``` PH = 7.35-7.45 pCO2 = 35-45 HCO3 = 22-26 ```