Unit 8 Flashcards
Isotonic Solutions Percent Salt:
0.9% NaCl
Isotonic Solutions Other names
- D5W (5% dextrose)
- Saline, NS, PS, PSS
- Ringer’s
- Lactated Ringer’s
- Milliosmoles: 300 milliosmoles/Liter (mOsm/L)
- Milliequivalents: 325 milliequivalents/Liter (mEq/L)
Hypertonic Solutions Percent Salt:
> 0.9% NaCl
- Milliosmoles: >300 milliosmoles/Liter (mOsm/L)
- Milliequivalents: >325 milliequivalents/Liter (mEq/L)
Hypertonic Solutions other name
D10W (>5% dextrose)
Hypotonic Solutions Percent Salt
<300 milliosmoles/Liter (mOsm/L)
Hypotonic Solutions other name
D2W (<5% dextrose)
Definition of osmosis
H2O moves toward the region of higher solute concentration
Isotonic Solution movement:
- causes no net water movement (cell is in equilibrium)
- cells in an isotonic solution show no change in size & function
Hypertonic Solution movement:
- draws H2O out of the cell
- cells crenate in a hypertonic solution; size + function both decrease
Hypotonic Solution movement:
- draws H2O into the cell
- cells in a hypotonic solution swell & may lyse; size increases, function decreases
Blood sodium levels drop from 325 mEq/L to 124 mEq/L
What is the danger?
-↓Sodium in the blood allows H2O to move into cells (osmosis)
-Less fluid in blood
-↓Blood volume
-↓Blood pressure
To correct this:
↑Heart rate will ↑blood pressure
What does electrolytes ionize into?
particles
Ex: NaCl –> Na+ + Cl-
Does glucose ionize?
Nonelectrolytes (Glucose), do not ionize
Organs That Regulate Fluid & Electrolyte Balance:
Brain, Adrenal Glands, Kidneys
List the steps of the thirst mechanism
DECREASED ECF VOLUME OR INCREASED ECF OSMOLALITY —>HYPOTHALAMUS—-> ↓SALIVA —->THIRST—>DRINK—>↑ ECF VOLUME
About Aldosterone
-Hormone (mineralocorticoid)
-Secreted by: adrenal cortex
-Stimulates kidneys to:
Reabsorb Na+, Cl–, H2O
Secrete K+
Estrogen
- Female hormone from the ovaries mimics aldosterone
- Stimulates kidneys to reabsorb sodium, chloride, water
- ↑Fluid retention (edema)
How does estrogen affect calcium?
Calcium Moves Into Bone
Cortisol
- Hormone (glucocorticoid) from the adrenal cortex that mimics aldosterone
- Converts lipids & protein to glucose (gluconeogenesis)
- Anti-inflammatory (vasoconstrictor)
What does ↑Cortisol causes:
Edema, ↑visceral fat deposition, ↓memory storage, ↓memory retrieval
What does Antidiuretic Hormone (ADH) do?
Saves water at the collecting duct
Calcitonin Increases! In which direction will calcium move?
blood —> bone
Parathyroid Hormone Increases! In which direction will calcium move?
bone —> blood
A person is in the hot sun for many hours resulting in water lost through perspiration
How does the body maintain homeostasis?
- Hypothalamus makes ↑Aldosterone & ↑ADH
- Kidneys produce ↓urine
- Hypothalamus will cause ↑thirst (thirst center)
A person urinates many times during the day but is able to sleep all night w/o the need to urinate
How is this explained?
Hypothalamus secretes ↑ADH during sleep (↑ADH prevents urination)
A person has had diarrhea for two days
Body potassium level is only 25% of normal value
Why is potassium level so low?
- Body has lost fluid & w/ this fluid, has lost potassium
- Patient must be given potassium immediately or the heart may develop arrhythmias (stop efficient pumping)
A patient has been unable to eat anything following surgery
The physician has ordered an IV of D5W
Why was this done?
- Fluid in the D5W will replace fluid that will naturally be lost due to not eating
- Dextrose (glucose) will provide an energy source for the body
Dr. Feelgood has told a patient that they need to flush the toxins & poisons out of their body
The patient has been given an IV of distilled water twice a week
What are the risks to the patient w/ this treatment?
- Distilled water is hypotonic to cells
- Red blood cells will lyse & release hemoglobin, creating a burden on the liver to cleanse the blood
- ↓Red blood cell count could make the patient anemic
A patient has had severe head trauma & there is swelling around the brain
The physician has ordered an IV of 20% glucose (D20W)
Why was this done?
20% Glucose is hypertonic
It will attract fluid from the brain into the blood, reducing the swelling around the brain
A patient has a history of hypertension
The physician has placed the patient on a ↓sodium diet
What is the reason for the ↓sodium diet?
- Salt makes the blood hypertonic
- Fluid will move by osmosis into the blood
- ↑Blood volume → ↑blood pressure
- Sodium ↑BP in ⅓ of patients (sodium sensitivity)
What is blood pH and its range
Blood pH = 7.40 (7.35 - 7.45)
What is blood pH regulated by?
Kidneys, Lungs, Blood Buffers
Response to acidosis:
Kidneys Secrete H+ and Reabsorb HCO3–
Response to alkalosis:
Kidneys Reabsorb H+ and Secrete HCO3–
What does the kidney secrete if the pH is too low?
Secrete hydrogen ions & reabsorb bicarbonate ions
What does the kidney reabsorb if the pH is too high?
Reabsorb hydrogen ions & secrete bicarbonate ions
Brethe FASTER or SLOWER to get rid of excess carbon dioxide if ↓pH ?
FASTER
-Carbon dioxide forms carbonic acid in the blood
Breath FASTER or SLOWER to retain carbon dioxide if ↑pH?
SLOWER
-Carbon dioxide combines w/ water to form carbonic acid in the blood
Equation of Carbon Dioxide + Water → Carbonic Acid
CO2 + H2O H2CO3 H+ + HCO3–
Breathing _______ will retain CO2 & pH will _______ (↑acidity & ↑H+)
slower, decrease
↑Carbon Dioxide → ↑Acidity → ↓pH
Breathing ______ will eliminate more CO2 & pH will ______ (↓acidity & ↓H+)
faster,increase
↓Carbon Dioxide → ↓Acidity → ↑pH
If blood pH decreases to 7.3 how does the body compensate?
- Breath faster to get rid of carbon dioxide, ↓acidity
- Hyperventilation
If blood pH increases to 7.5how does the body compensate?
- Breath slower to retain more carbon dioxide, ↑acidity
- Hypoventilation
A patient takes narcotics for painwhich have decreased breathing rate…what happens to blood pH?
pH will decrease because carbon dioxide is retained, which will ↑blood acidity & ↑H+
A person takes caffeine for energywhich has increased breathing rate…what happens to blood pH?
pH will increase because carbon dioxide is not retained, which will ↓blood acidity & ↓H+
Definition of Buffers
- Buffers resist changes in pH
- Prevent excessive pH changes in the body if an acid or base is added to the body
Definition of Strong Acid
- Acid that releases many hydrogen ions
- Hydrochloric acid
- HCl → H+ + Cl–
Defintion of Weak acid
- Acid that releases few hydrogen ions
- Carbonic acid
- H2CO3 → H+ + HCO3–
Buffers change ______ acids to ______ acids: strong acid + buffer → weak acid + salt
strong, weak
HCl (strong acid) + NaHCO3 (buffer) —> H2CO3 (weak acid) + NaCl (salt)
Bicarbonate Ion:Carbonic Acid Ratio
20:1 = pH 7.4
21:1 = pH more than 7.4
19:1 = pH less than 7.4
NOTE: THESE ARE RATIOS
Define & give the cause of Acidosis
- pH falls below 7.35
- ↓Nervous system function
- Coma
- Acidotic shock
Define & give the cause of Alkalosis
- pH climbs above 7.45
- ↑Nervous system function
- Convulsions
- Alkalotic shock
Define & give the cause of Respiratory Acidosis
- Decrease in respiratory rate (hypoventilation)
- ↑Carbon dioxide in the blood
- ↑Carbon dioxide level → ↓pH
Define & give the cause of Respiratory Alkalosis
- Increase in respiratory rate (hyperventilation)
- ↓Carbon dioxide in the blood
- ↓Carbon dioxide level → ↑pH
Define & give the cause of Metabolic Acidosis
- NOT caused by breathing or carbon dioxide imbalance
- ↑Acid (↑H+) in blood:
- Renal disease (unable to secrete H+)
- Diabetes mellitus, ↑fat diet, starvation, ↑ketones (ketosis → ketoacidosis)
- ↓Bicarbonates in blood
- ↑Hydrogen ions in blood
- ↑Acids in food
- ↓Bases in food
- Diarrhea
Define & give the cause of Metabolic Alkalosis
- NOT caused by breathing or a carbon dioxide imbalance
- ↓Acid (↓H+) in blood:
- Vomiting
- Diuretics
- ↑Bicarbonate in blood
- ↑Sodium bicarbonate ingestion
- ↑Bases in food
- ↓Acids in food
Name the 4 ECF ions
↑Na+ (Sodium),↑Cl– ( Chloride),↑Ca+2 (Calcium), ↑HCO3– (Bicarbonate)
Name the 4 ICF Ions
↑K+ (Potassium), ↑Mg+2 (Magnesium), ↑SO4–2 (sulfate), ↑HPO4–2 (phosphate)
Sodium Functions
- Attracts water to the ECF
- Nerve impulses
- Muscle contractions
Hypernatremia:
- ↑Sodium in the blood
- Hypertension
- Muscle twitching
- Mental confusion
- Coma
Hyponatremia:
- ↓Sodium in the blood
- Hypotension
- Tachycardia
- Muscle weakness
Potassium Functions
- Attracts water into the ICF
- Nerve impulses
- Muscle contractions
Hyperkalemia:
- ↑Potassium in the blood
- Cardiac arrhythmias
- Cardiac arrest
- Elevated T-wave (ECG)
- Muscle weakness
Hypokalemia:
- ↓Potassium in the blood
- Cardiac arrhythmias
- Cardiac arrest
- Depressed T-wave (ECG)
- Muscle weakness
Calcium Functions
- Bones & teeth
- Blood clotting
- Nerve impulses
- Muscle contraction
Hypercalcemia:
- ↑Calcium in the blood
- Renal calculi (kidney stones)
- Cardiac arrhythmias
Hypocalcemia:
- ↓Calcium in the blood
- Muscle tetany
- Weak cardiac muscle contractions
- ↑Clotting time
Aldosteronism:
- ↑Aldosterone production
- ↑Blood sodium levels
- ↓Blood potassium levels
- Hypertension
Addison’s Disease
- Hyposecretion of the Adrenal Cortex
- ↓Aldosterone (mineralocorticoid)
- ↓Cortisol (glucocorticoid)
- Cortisol converts protein → glucose)
- Hypotension (↓sodium)
- Hypoglycemia (↓glucocorticoids)
Cushing’s Disease
- ↑Glucocorticoids
- Adrenal gland tumor
- Side effect of cortisol
- Hyperglycemia
- Abdominal fat accumulation
- Posterior neck hump
True or false: Addison is similar to Cushing’s Disease.
FALSE! They are basically opposites! (check powerpoint on slide 93)
↑Antidiuretic Hormone (ADH) in a hypertonic interstitial fluid
↑ADH goes in collecting duct, ↑H2O comes out, and ↓Urine output
↓Antidiuretic Hormone (ADH) in a Hypertonic Interstitial Fluid
:
↓ADH goes into the collecting duct, ↓H2O comes out, and ↑Urine output
Cause of Diabetes Insipidus
- ↓ADH secretion
- ↓ADH receptors (at kidneys)
Effect of Diabetes Insipidus
- ↑Urination
- Dehydration
