NSG 3850 PATHOPHYSIOLOGY
Comprehensive Exam Study Guide & Clinical Reasoning Resource
Fluids & Electrolytes • Acid-Base • Hematology • Pulmonary • Renal • Cardiovascular • GI | 2026–
2027 Edition
SEO TITLE:
NSG 3850 Pathophysiology Exam Study Guide 2026–2027 | Fluids, Electrolytes,
Acid-Base, Anemia, Pulmonary, Renal & Cardiovascular Disorders with Clinical
Reasoning Answers
This comprehensive resource integrates all major NSG 3850 Pathophysiology exam content. Each question
includes the correct answer and detailed clinical reasoning to build conceptual understanding — not just rote
memorization. Organized by body system for efficient studying.
, SECTION 1: Core Pathophysiology Concepts & Glossary
Fluid Compartments & Movement
CONCEPT DEFINITION / KEY FACTS
Intracellular Fluid (ICF) 2/3 of TBW; rich in K+, Mg2+, phosphate; low in Na+, Cl-
Extracellular Fluid (ECF) 1/3 of TBW; includes vascular (protein-rich) and interstitial (protein-
poor) compartments
Transcellular Fluid CSF, pleural, synovial fluid; rich in Na+, Cl-, HCO3-; low in K+,
Mg2+, phosphate
Osmosis Water moves from low to high solute concentration (low to high)
Diffusion Solutes move from high to low concentration (high to low)
Capillary Hydrostatic Outward-pushing force of vascular fluid against capillary walls —
Pressure promotes filtration
Capillary Osmotic (Oncotic) Inward-pulling force of plasma proteins — opposes filtration, pulls
Pressure fluid back into vessels
ADH (Vasopressin) Free water hormone; causes renal collecting duct reabsorption of
water; released in response to increased osmolarity or decreased BP
Aldosterone Salt-water hormone; causes renal tubule reabsorption of Na+ and
water; expands ECF volume
Osmotic Diuresis Increased urine output caused by excretion of solutes (glucose,
mannitol) pulling water with them
Electrolyte Imbalance Summary Table
ELECTROLYTE DEFICIENCY (HYPO-) EXCESS (HYPER-) KEY MNEMONICS/NOTES
Sodium (Na+) Confusion, lethargy, Thirst, weakness, seizures, Sodium governs WATER
seizures, cramping; coma; causes: DI, tube feeding movement; Na imbalances =
causes: excessive ADH, w/o flushes, hypertonic saline CNS symptoms (seizures
hypotonic irrigation, risk!)
diuretics, GI loss
Potassium (K+) Cardiac dysrhythmias, U Cardiac arrest, peaked T waves, Thiazide/loop diuretics →
wave on ECG, muscle weakness, increased GI motility; hypokalemia. Oliguric renal
weakness, decreased GI causes: ESRD, oliguric AKI failure → hyperkalemia
motility; causes:
diuretics, insulin OD
Calcium (Ca2+) Chvostek & Trousseau Lethargy, bone pain, renal Ca & Phosphate are
signs, tetany, seizures, calculi, constipation, INVERSE. Positive
circumoral numbness; dysrhythmias; causes: Chvostek/Trousseau =
causes: hyperparathyroidism, hypocalcemia
hypoparathyroid, malignancy
pancreatitis
Magnesium Tremors, hyperactive Flushing, hypotension, Low Mg → think chronic
(Mg2+) DTRs, tachycardia, drowsiness, decreased DTRs, alcoholism. High Mg →
,ELECTROLYTE DEFICIENCY (HYPO-) EXCESS (HYPER-) KEY MNEMONICS/NOTES
seizures, torsades de bradycardia, cardiac arrest; decreased neuromuscular
pointes; causes: causes: renal failure, excess excitability
alcoholism, diuretics antacids
Phosphate (PO4) ATP deficiency → Inverse hypocalcemia Antacids (Mg-Al) bind
cellular dysfunction; symptoms; causes: ESRD, phosphate →
causes: antacid overuse, rhabdomyolysis, tumor lysis; hypophosphatemia. ESRD
malnutrition, DKA pruritis is major sign → hyperphosphatemia
treatment
Acid-Base Balance Overview
DISORDER pH PRIMARY CHANGE COMMON CAUSES
Respiratory ↓ (<7.35) ↑ PaCO2 (CO2 Hypoventilation, narcotic OD,
Acidosis retention) COPD, sleep apnea, chest wall
weakness
Respiratory ↑ (>7.45) ↓ PaCO2 (CO2 blown Hyperventilation, anxiety, pain,
Alkalosis off) fever, high altitude, brain stem
injury
Metabolic Acidosis ↓ (<7.35) ↓ HCO3- DKA, lactic acidosis, diarrhea,
ESRD, aspirin OD, tissue hypoxia,
burns
Metabolic Alkalosis ↑ (>7.45) ↑ HCO3- Vomiting, NG suction, antacid
excess, hypokalemia
Anemia Classification Table
TYPE MCV / MCHC KEY LABS CAUSE / NOTES
Iron Deficiency Low (microcytic), ↑ TIBC, ↓ serum Most common anemia; poor diet, blood
low MCHC iron, ↓ ferritin loss; hypochromic, microcytic
Pernicious / B12 High (macrocytic) ↓ B12, ↑ MCV; Lack of intrinsic factor → B12 deficiency;
peripheral nerve megaloblastic changes in marrow
degeneration
Folate Deficiency High (macrocytic) ↓ folate, ↑ MCV; no Alcoholism, pregnancy, cirrhosis, infancy;
neuro symptoms DNA synthesis disruption
Aplastic Anemia Variable Pancytopenia (↓ Bone marrow failure; toxic/immune injury;
RBC, WBC, treat with soft toothbrush for bleeding risk
platelets)
Hemolytic Anemia Variable ↑ bilirubin RBC destruction; causes: sickle cell,
(jaundice), ↑ thalassemia, Rh incompatibility
reticulocytes, ↑
LDH
Thalassemia Low (microcytic) Reticulocytosis, Genetic; like iron deficiency but does
hepato/splenomega NOT respond to iron; excessive intestinal
ly iron absorption
Sickle Cell Variable Positive Hgb HbS polymerization → vascular
electrophoresis occlusion, pain crisis; affects spleen,
bones, brain, lungs
, TYPE MCV / MCHC KEY LABS CAUSE / NOTES
Anemia of Renal Normal ↓ EPO; Hgb/Hct Kidney cannot produce adequate
Failure low; normal iron erythropoietin; treat with EPO therapy
Comprehensive Exam Study Guide & Clinical Reasoning Resource
Fluids & Electrolytes • Acid-Base • Hematology • Pulmonary • Renal • Cardiovascular • GI | 2026–
2027 Edition
SEO TITLE:
NSG 3850 Pathophysiology Exam Study Guide 2026–2027 | Fluids, Electrolytes,
Acid-Base, Anemia, Pulmonary, Renal & Cardiovascular Disorders with Clinical
Reasoning Answers
This comprehensive resource integrates all major NSG 3850 Pathophysiology exam content. Each question
includes the correct answer and detailed clinical reasoning to build conceptual understanding — not just rote
memorization. Organized by body system for efficient studying.
, SECTION 1: Core Pathophysiology Concepts & Glossary
Fluid Compartments & Movement
CONCEPT DEFINITION / KEY FACTS
Intracellular Fluid (ICF) 2/3 of TBW; rich in K+, Mg2+, phosphate; low in Na+, Cl-
Extracellular Fluid (ECF) 1/3 of TBW; includes vascular (protein-rich) and interstitial (protein-
poor) compartments
Transcellular Fluid CSF, pleural, synovial fluid; rich in Na+, Cl-, HCO3-; low in K+,
Mg2+, phosphate
Osmosis Water moves from low to high solute concentration (low to high)
Diffusion Solutes move from high to low concentration (high to low)
Capillary Hydrostatic Outward-pushing force of vascular fluid against capillary walls —
Pressure promotes filtration
Capillary Osmotic (Oncotic) Inward-pulling force of plasma proteins — opposes filtration, pulls
Pressure fluid back into vessels
ADH (Vasopressin) Free water hormone; causes renal collecting duct reabsorption of
water; released in response to increased osmolarity or decreased BP
Aldosterone Salt-water hormone; causes renal tubule reabsorption of Na+ and
water; expands ECF volume
Osmotic Diuresis Increased urine output caused by excretion of solutes (glucose,
mannitol) pulling water with them
Electrolyte Imbalance Summary Table
ELECTROLYTE DEFICIENCY (HYPO-) EXCESS (HYPER-) KEY MNEMONICS/NOTES
Sodium (Na+) Confusion, lethargy, Thirst, weakness, seizures, Sodium governs WATER
seizures, cramping; coma; causes: DI, tube feeding movement; Na imbalances =
causes: excessive ADH, w/o flushes, hypertonic saline CNS symptoms (seizures
hypotonic irrigation, risk!)
diuretics, GI loss
Potassium (K+) Cardiac dysrhythmias, U Cardiac arrest, peaked T waves, Thiazide/loop diuretics →
wave on ECG, muscle weakness, increased GI motility; hypokalemia. Oliguric renal
weakness, decreased GI causes: ESRD, oliguric AKI failure → hyperkalemia
motility; causes:
diuretics, insulin OD
Calcium (Ca2+) Chvostek & Trousseau Lethargy, bone pain, renal Ca & Phosphate are
signs, tetany, seizures, calculi, constipation, INVERSE. Positive
circumoral numbness; dysrhythmias; causes: Chvostek/Trousseau =
causes: hyperparathyroidism, hypocalcemia
hypoparathyroid, malignancy
pancreatitis
Magnesium Tremors, hyperactive Flushing, hypotension, Low Mg → think chronic
(Mg2+) DTRs, tachycardia, drowsiness, decreased DTRs, alcoholism. High Mg →
,ELECTROLYTE DEFICIENCY (HYPO-) EXCESS (HYPER-) KEY MNEMONICS/NOTES
seizures, torsades de bradycardia, cardiac arrest; decreased neuromuscular
pointes; causes: causes: renal failure, excess excitability
alcoholism, diuretics antacids
Phosphate (PO4) ATP deficiency → Inverse hypocalcemia Antacids (Mg-Al) bind
cellular dysfunction; symptoms; causes: ESRD, phosphate →
causes: antacid overuse, rhabdomyolysis, tumor lysis; hypophosphatemia. ESRD
malnutrition, DKA pruritis is major sign → hyperphosphatemia
treatment
Acid-Base Balance Overview
DISORDER pH PRIMARY CHANGE COMMON CAUSES
Respiratory ↓ (<7.35) ↑ PaCO2 (CO2 Hypoventilation, narcotic OD,
Acidosis retention) COPD, sleep apnea, chest wall
weakness
Respiratory ↑ (>7.45) ↓ PaCO2 (CO2 blown Hyperventilation, anxiety, pain,
Alkalosis off) fever, high altitude, brain stem
injury
Metabolic Acidosis ↓ (<7.35) ↓ HCO3- DKA, lactic acidosis, diarrhea,
ESRD, aspirin OD, tissue hypoxia,
burns
Metabolic Alkalosis ↑ (>7.45) ↑ HCO3- Vomiting, NG suction, antacid
excess, hypokalemia
Anemia Classification Table
TYPE MCV / MCHC KEY LABS CAUSE / NOTES
Iron Deficiency Low (microcytic), ↑ TIBC, ↓ serum Most common anemia; poor diet, blood
low MCHC iron, ↓ ferritin loss; hypochromic, microcytic
Pernicious / B12 High (macrocytic) ↓ B12, ↑ MCV; Lack of intrinsic factor → B12 deficiency;
peripheral nerve megaloblastic changes in marrow
degeneration
Folate Deficiency High (macrocytic) ↓ folate, ↑ MCV; no Alcoholism, pregnancy, cirrhosis, infancy;
neuro symptoms DNA synthesis disruption
Aplastic Anemia Variable Pancytopenia (↓ Bone marrow failure; toxic/immune injury;
RBC, WBC, treat with soft toothbrush for bleeding risk
platelets)
Hemolytic Anemia Variable ↑ bilirubin RBC destruction; causes: sickle cell,
(jaundice), ↑ thalassemia, Rh incompatibility
reticulocytes, ↑
LDH
Thalassemia Low (microcytic) Reticulocytosis, Genetic; like iron deficiency but does
hepato/splenomega NOT respond to iron; excessive intestinal
ly iron absorption
Sickle Cell Variable Positive Hgb HbS polymerization → vascular
electrophoresis occlusion, pain crisis; affects spleen,
bones, brain, lungs
, TYPE MCV / MCHC KEY LABS CAUSE / NOTES
Anemia of Renal Normal ↓ EPO; Hgb/Hct Kidney cannot produce adequate
Failure low; normal iron erythropoietin; treat with EPO therapy
