Fluid balance
Identify the major fluid compartments in the body and examples
Intracellular (ICF)
Extracellular (ECF)
Describe how body water content changes as a person ages.
High body water content as a baby and it gradually declines as you get older.
Compare body water content between genders
More in male than in the female because women have more fat or adipose and men have more muscle which has more fluid than fat.
Define an electrolyte and how electrolyte concentrations in the body are expressed.
Electrolytes are chemical compounds that do dissociate into ions in water.
Expressed in Milliequivalents/Liter (mEq/L), measure of the number of electrical charges in 1 liter of solution.
Describe the distribution of electrolytes in ICF and ECF. What are the major intracellular electrolytes? The major extracellular electrolytes
K+ is largest in intracellular inside of cell also phosphate because used for ATP
Na+ CL- extracellular outside of cell mostly
Describe fluid movement among compartments
Water moves freely to and from Plasma into Interstitial space and to and from Intracellular.
Plasma cannot "jump" to Intracellular, must go through Interstitial space first!
Describe major sources of water intake and output
We get most of our water intake through drinking than eating than metabolism. We lose the most in urine, insensible losses skin and lung, sweat than feces
Describe the thirst mechanism
These 3 stimuli activates the hypothalamic thirst center (TC) in the brain.
Describe how ADH is related to water output. Where does ADH target?
ADH is related to water out put because,
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Question 9 Describe how ADH is related to water output. Where does ADH target?
ADH determines the amount of water the Kidney withholds in the blood or excretes in the urine.
ADH targets the cells of the tubules and collecting ducts.
Note: With more fluid being reabsorbed the blood volume increases while the solutes concentration becomes more diluted.
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List 4 Mechanisms that regulate Water Homeostasis.
What does ADH do?
Reabsorbs water to make the urine more concentrated
What is Dehydration?
Cells shrink due to loss of water. You lose more water than what you are gaining, so there is a shortage and ADH is activated.
Describe disorders of water balance: Dehydration
Slide 35
Diabetes mellitus (hypertonic filtrate)
Diabetes insipidis (low insulin)
Hypovolemic shock
Hyperthermia
Causes of Dehydration: Hemorrhage, diarrhea, burns, vomiting, sweating, deprivation.
What is Hypotonic hydration?
"More" water input than water output. Occurs within the Intracellular fluid (ICF), inside the cell.
Too much water will dilute electrolytes.
Describe disorders of water balance: Hypotonic hydration
Hyponatremia (low Na+ concentration) drinking lots of h2O, but losing Na+ in sweat
Cerebral Edema
Convulsions
Coma
Death
What is Edema?
Edema is "too much" water in the extracellular fluid (ECF) that causes tissue to swell. Will block the lymphatic system.
Describe disorders of water balance: Edema
Lymphatic Filariasis Disease
Blocked Lymphatic vessels
Describe the 4 mechanisms that regulate water balance
If fluid osmolarity increases 1-2 % or if blood volume drops by 10% BP goes down which in turn activates.
Describe how aldosterone and ANP affects sodium and water balance
Aldosterone draws in sodium to be reabsorbed in the DCT, which allows water to follow. Slide 29
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Describe how aldosterone affects potassium balance
Aldosterone influences K+ secretion into the filtrate by stimulating the cells to reabsorb Na+, while enhancing K+ secretion.
As a result, K+ controls its own concentration within the ECF via feedback regulation on aldosterone release.
Pg 1003
ID the target of aldosterone.
Aldosterone regulates water homeostasis by secretion (blood loss) to increase blood volume. Aldosterone targets kidney tubules. It increases Na+ reabsorption and increases K+ secretion.
Slide 22
Describe what hormones regulate Calcium/phosphate balance in the body and their targets
The parathyroid hormone (PTH) increases Ca+ reabsorption by the renal tubules while decreasing phosphate ion reabsorption. Pg 1003
This enhances the blood Ca+ levels by targeting the bones, kidneys, and intestine.
Pg 1015 section 12/13- Regulation of Calcium/Phosphate Balance in Summary section.
Describe the normal pH of arterial blood, urine, intracellular fluid, stomach and intestine
Arterial blood- 7.35-7.45
Urine-6.0-8.0
Intracellular fluid-7.0
Stomach -2.0
Intestine-8.0
Define acidosis and alkalosis
Acidosis - a drop in arterial blood pH below 7.35
Alkalosis - a pH of arterial blood that rises above 7.45
Describe the effect of H+ and HCO3- ions on pH of a solution
The higher the hydrogen then it is more acidic
The higher the bicarbonate then it is more basic or alkaline and vice versa
Describe the 3 ways the body can regulate H+ concentration in the blood.
Describe the 3 chemical buffer systems and give their locations in the body
Bicarbonate buffer
Phosphate buffer
Protein buffer (Can act as acid or base)
Describe the influence of the respiratory system on acid-base balance.
Respiratory system alters carbonic acid (H+) to gain or lose, which changes respiration depth/rate (Hypo/Hyper ventilation) to eliminate CO2
Describe how the kidneys regulate hydrogen and bicarbonate ion concentrations in the blood
Secreted hydrogen ions come from the dissociation of carbonic acid generated within the tubule cells.
To counteract alkalosis, bicarbonate ion is secreted into the filtrate and H+ is reabsorbed.
Pg 1015 section 13 under renal Mechanisms of acid-base baance in Summary section.
Describe metabolic and respiration acidosis
Metabolic acidosis is HCO3 reduction, acid build-up
Respiration acidosis is CO2 buildup, poor gas exchange
Describe metabolic and respiratory alkalosis
Metabolic alkalosis is loss of acid, build-up of HCO3
Respiration alkalosis is hyperventilation, CO2 reduction
Describe metabolic and respiratory compensation.
Name imbalances (too high or too low) of sodium, potassium, phosphate, chloride, calcium and magnesium
We don't need answer's below
potassium imbalance disorders:
Potassium
HYPERKALEMIA.Hyperkalemiamay becaused byketoacidosis(diabeticcoma),myocardialinfarction (heart attack),severeburns,kidneyfailure,fasting,bulimianervosa,gastrointestinalbleeding,adrenalinsufficiency, orAddison'sdisease.Diureticdrugs,cyclosporin,lithium,heparin,ACEinhibitors,beta blockers,andtrimethoprimcanincreaseserumpotassiumlevels, ascanheavyexercise.Theconditionmayalso besecondary tohypernatremia(lowserumconcentrations ofsodium).Symptomsmayinclude:
HYPOKALEMIA.Severedehydration,aldosteronism,Cushing'ssyndrome,kidneydisease,long-termdiuretictherapy,certainpenicillins,laxativeabuse,congestiveheart failure,andadrenalglandimpairmentscanallcausedepletion ofpotassiumlevels inthebloodstream. Asubstanceknown asglycyrrhetinicacid,which isfound inlicoriceandchewingtobacco,canalsodepletepotassiumserumlevels.Symptoms ofhypokalemiainclude:
Calcium imbalance
Calcium
HYPERCALCEMIA.Bloodcalciumlevelsmay beelevated incases ofthyroiddisorder,multiple myeloma,metastaticcancer,multiplebonefractures,milk-alkalisyndrome,andPaget'sdisease.Excessiveuse ofcalcium-containingsupplementsandcertainover-the-countermedications(i.e.,antacids)mayalsocausehypercalcemia. Ininfants,lesserknowncausesmayincludebluediapersyndrome,Williamssyndrome,secondaryhyperparathyroidismfrommaternalhypocalcemia,anddietaryphosphatedeficiency.Symptomsinclude:
HYPOCALCEMIA.Thyroiddisorders,kidneyfailure,severeburns,sepsis,vitamin Ddeficiency,andmedicationssuch asheparinandglucogancandepletebloodcalciumlevels.Loweredlevelscause:
magnesium imbalance:
Magnesium
HYPERMAGNESEMIA.Excessivemagnesiumlevelsmayoccurwithend-stagerenaldisease,Addison'sdisease, or anoverdose ofmagnesiumsalts.Hypermagnesemia ischaracterizedby:
HYPOMAGNESEMIA.Inadequatedietaryintake ofmagnesium,oftencaused bychronicalcoholism ormalnutrition, is acommoncause ofhypomagnesemia.Othercausesincludemalabsorptionsyndromes,pancreatitis,aldosteronism,burns,hyperparathyroidism,digestivesystemdisorders,anddiureticuse.Symptoms oflowserummagnesiumlevelsinclude:
Chloride disorder:
Chloride
HYPERCHLOREMIA.Severedehydration,kidneyfailure,hemodialysis,traumaticbraininjury,andaldosteronismcanalsocausehyperchloremia.Drugssuch asboricacidandammoniumchlorideandtheintravenous(IV)infusion ofsodiumchloridecanalsoboostchloridelevels,resulting inhyperchloremicmetabolic acidosis.Symptomsinclude:
HYPOCHLOREMIA. Hypochloremia usually occurs as a result of sodium and potassium depletion (i.e., hyponatremia, hypokalemia). Severe depletion of serum chloride levels causes metabolic alkalosis.Thisalkalization ofthebloodstream ischaracterizedby:
phosphate disorder:
Phosphate
HYPERPHOSPHATEMIA.Skeletalfractures ordisease,kidneyfailure,hypoparathyroidism,hemodialysis,diabeticketoacidosis,acromegaly,systemicinfection,andintestinalobstructioncanallcausephosphateretentionandbuild-up intheblood.Thedisorderoccursconcurrentlywithhypocalcemia.Individualswithmildhyperphosphatemiaaretypicallyasymptomatic,butsigns ofseverehyperphosphatemiainclude:
HYPOPHOSPHATEMIA.Serumphosphatelevels of 2mg/dL orbelowmay becaused byhypomagnesemiaandhypokalemia.Severeburns,alcoholism,diabetic ketoacidosis,kidneydisease,hyperparathyroidism,hypothyroidism,Cushing'ssyndrome,malnutrition,hemodialysis,vitamin D deficiency,andprolongeddiuretictherapycanalsodiminishbloodphosphatelevels.Therearetypicallyfewphysicalsigns ofmildphosphatedepletion.Symptoms ofseverehypophosphatemiainclude: