Chapter 27: Fluids

Question 1

Fluid Compartments: Solutes and Solution

Answer 1

Solution= Solvent+Solutes
Solvent=H20
Solutes=Dissolved

Question 1

Fluid Compartments

Answer 1

Body fluid compartments:
⅔ Intracellular fluid (Majority)
⅓ Extracellular fluid (80% Interstitial, 20% Plasma)

Question 2

Fluid Balance

Answer 2

Depends on electrolyte balance
Sodium and Chloride are the most important for regulation of fluid balance

Question 3

Sources of Water (Solvent) Gain

Answer 3

Ingestion (GI Tract)
Formation of metabolic water (formed in aerobic cellular respiration)
Thirst Center=Hypothalamus

Question 4

Regulation of Water Gain and Loss

Answer 4

Excess solutes lost in concentrated urine
Excess water lost as dilute urine
Regulated by Kidney

Question 5

Water Gains and Loss by #’s

Answer 5

Water gain: Ingestion
Water loss: Kidneys

Question 6

Sodium Loss and Conservation

Answer 6

Factors causing natriuresis (loss of Na+(sodium ions) in urine) results in decreased body fluid (blood) volume and decreased blood pressure.

Aldosterone and angiotensin II inhibit sodium loss in the urine, which increases blood volume and blood pressure.

Lower NA+ in Blood= Lower Blood Volume= Lower BP

Aldosterone Secreted= Increased Na+ in the blood= Higher Blood Volume= Higher BP
(Not losing Na+ in urine)

Question 7

Blood Osmolarity and Control of Water Loss: PT.1

Answer 7

Factors causing loss of water in urine (dilute urine) results in increased osmolarity of blood

Increased Osmolarity of blood= Increased Solutes in the blood

If blood osmolarity is decreased= ADH (antidiuretic hormone) secretion is deceased which results in increased water loss in urine (Production of dilute urine)

Osmolarity of blood is then increased (return to homeostasis)

Losing H2O from blood= Increased solutes in blood

Question 8

Blood Osmolarity and Control of Water Loss: Dilute and Concentrated Urine

Answer 8

Formation of Dilute Urine:
Decreased Solutes in the blood= Decreased ADH (Holding onto it) (Anti AntiDiuresis)= Loss of water in urine= Increased Solutes in the blood

Formation of Concentrated Urine:
Retain H2O in the blood= Decreased solutes in the blood (decreased osmolarity)

Increased solutes in the blood= Increased ADH= Collecting Ducts Open= Decreased H2O in the filtrate= Decreased H2O lost in Urine= Decreased Solutes in the blood

Question 9

Movement of Water between Fluid Compartments

Answer 9

Changes in osmolarity of ECF can cause movement of water (by osmosis) into or out of cells.

Water intoxication: Significant decreased ECF osmolarity leading to swelling of cells; can cause death

Question 10

Increased and Decreased ADH

Answer 10

Increased ADH→ Collecting ducts porous→ H2O moves from filtrate back into blood
Decreased ADH→ Collecting ducts close→ H2O stays in the filtrate→ Urine

Question 11

Most of the water in the body is intracellular

Answer 11

Most of the water in the body is intracellular

Question 12

Functions of Electrolytes

Answer 12

Control Osmosis
Maintains acid base balance
Electrical current
Cofactors for enzyme function

Question 13

Sodium and Chloride

Answer 13

Sodium (Na+): 90% of extracellular cation
Excess sodium leads to water retention (Edema; accumulation of interstitial fluid)
Too much sodium loss in urine results in hypovolemia (low blood volume)
Chloride (CI-): Follows sodium. Most prevalent anion in extracellular fluid

Question 14

Ions: Potassium and Bicarbonate

Answer 14

Potassium (K+): Major intracellular cation
Regulated by aldosterone
Bicarbonate (HCO3-): Transport form of CO2 in blood
Regulated by Kidneys
Buffers acid in blood for PH maintenance

Question 15

Ions: Calcium, Phosphate, and Magnesium

Answer 15

Calcium (Ca2+): Blood levels regulated by PTH
Phosphate: Acid buffer

Question 16

Acid Base Balance

Answer 16

Maintenance of H+ (hydrogen) concentration (pH) at appropriate level (7.35-7.45)
Buffer System: Bind H+ but do not remove it
Exhalation of CO2: Reduces carbonic acid
excretion of H+ by kidneys

Question 17

Mechanisms of pH Balance

Answer 17

Kidney Excretion: Can reabsorb filtered bicarbonate or create new bicarbonate, can excrete all types of acids in the urine

Question 18

Blood pH

Answer 18

Normal: 7.35-7.45
Acidosis: Blood pH < 7.35 (Higher concentration)
Alkalosis: Blood pH >7.45 (Lower concentration)

Question 19

Acid Base Imbalances

Answer 19

Respiratory acidosis: Due to buildup of CO2
Respiratory alkalosis:
Due to hyperventilation
Metabolic Acidosis: Not enough bicarbonate ion (due to diarrhea)
Metabolic Alkalosis:
Not enough hydro ions in your system (due to vomiting)