Pathophysiology Exam 2 Comprehensive Study Guide: Fluid and Electrolyte Balance, Acid-Base Disorders, Hematologic Pathophysiology, Cardiovascular Disorders, Shock States, and Respiratory System Pathophysiology with Laboratory Findings and Clinical Manifes

This comprehensive Pathophysiology Exam 2 study guide provides an extensive collection of high-yield practice questions with detailed answer rationales covering essential pathophysiological concepts across multiple body systems. The document is meticulously structured to facilitate critical thinking and clinical judgment development for nursing students preparing for pathophysiology examinations, the HESI exit exam, NCLEX, and other comprehensive nursing assessments. This set emphasizes the integration of pathophysiologic mechanisms with clinical manifestations, laboratory findings, and evidence-based nursing interventions. Key Content Areas Covered: 1. Fluid Compartments and Distribution Blood plasma located in the intravascular fluid compartment (extracellular fluid) Total body water calculation: approximately 60% of body weight (42 L for a 70 kg person) Intracellular fluid (ICF) comprising approximately 40% of body weight (28 L for a 70 kg person) Extracellular fluid (ECF) comprising approximately 20% of body weight (14 L) Interstitial fluid, intravascular fluid, and transcellular fluid compartments Water movement between ICF and ECF determined by osmotic forces Starling forces affecting fluid movement including capillary hydrostatic pressure and capillary oncotic pressure 2. Fluid Imbalances and Edema Dehydration risk in elderly individuals due to decreased thirst sensation, decreased renal concentrating ability, and total body water decrease Decreased oncotic pressure in capillaries due to liver failure (decreased albumin production) or nephrotic syndrome (protein loss) Increased capillary hydrostatic pressure in chronic renal failure causing edema Localized edema versus generalized edema (anasarca) Cerebral edema as a localized type of edema Third spacing in liver cirrhosis with ascites due to increased capillary filtration pressure and decreased plasma oncotic pressure Increased capillary filtration pressure from excessive intravenous normal saline administration Hypertonic intravenous solution administration for severe dehydration causing intracellular dehydration 3. Hormonal Regulation of Fluid and Electrolyte Balance Antidiuretic hormone (ADH) secretion stimulated by increased plasma osmolality ADH promoting water reabsorption in the collecting ducts Aldosterone secretion resulting in increased blood volume through sodium and water reabsorption Aldosterone promoting potassium excretion (decreased blood K+ levels) Natriuretic hormones affecting sodium balance and promoting sodium excretion Syndrome of inappropriate antidiuretic hormone (SIADH) with excessive ADH secretion causing water retention, hyponatremia, and weight gain Diabetes insipidus with decreased ADH causing excessive water loss and hypernatremia 4. Sodium and Potassium Disorders Hypernatremia risk in patients with dehydration, inadequate water intake, or excessive water loss Pure water deficit most commonly caused by renal water loss Hypertonic hyponatremia associated with hyperlipidemia and hyperglycemia Decreased sodium levels in diabetic patients with hyperglycemia due to dilutional hyponatremia Hyperkalemia caused by acute acidosis, renal failure, and increased potassium intake Hyperkalemia causing increased resting membrane potential with decreased excitability of cardiac muscle Hypokalemia caused by primary hyperaldosteronism, diuretic use, and gastrointestinal losses Hypochloremia in patients with increased bicarbonate intake Long-term potassium deficits requiring monitoring of kidney function Magnesium's critical role in cellular energy metabolism, sodium-potassium pump function, and nerve conduction 5. Acid-Base Balance and Disorders Normal arterial blood gas values: pH 7.35–7.45, PaCO₂ 35–45 mmHg, HCO₃ 21–27 mEq/L Respiratory acidosis with decreased pH, increased CO₂, and normal bicarbonate (acute) or increased bicarbonate (chronic compensation) Chronic compensation for respiratory acidosis by the body including increased bicarbonate reabsorption by the kidneys Respiratory alkalosis with elevated pH, decreased PCO₂, and slightly decreased HCO₃ Metabolic acidosis with decreased pH, decreased HCO₃, and decreased PCO₂ (respiratory compensation) Metabolic alkalosis from excessive baking soda ingestion with compensatory respiratory depression of CO₂ elimination Immediate buffering systems including protein buffering and carbonic acid formation Kussmaul respirations in metabolic acidosis (rapid, deep breathing) Acid-base imbalance in acute renal failure with metabolic acidosis 6. Cellular Pathophysiology and Membrane Transport Skeletal muscle cells being multinucleated and lacking true cell boundaries Squamous epithelial cells of the skin exhibiting the highest rate of turnover and renewal Desmosome dysfunction resulting in separation at the junctions between epithelial cells Glycolysis occurring in cells without mitochondria Membrane transport mechanisms requiring the greatest amount of energy (active transport) Glucose transport across cell membranes in type 1 diabetes mellitus requiring insulin-dependent glucose transporters Cellular energy metabolism and ATP production Sodium-potassium pump function requiring magnesium Nerve conduction requiring magnesium Cellular adaptations to stress including atrophy, hypertrophy, hyperplasia, metaplasia, and dysplasia 7. Genetic and Molecular Pathophysiology Dominant genetic traits expressed in either homozygous or heterozygous pairing Gene dosage studies as a method of genetic mapping focusing on measurement of enzyme activity RNA interference in disease treatment by stopping faulty gene activity that produces unwanted proteins Mitochondrial DNA located outside the nucleus Recombinant DNA technology applications including production of human insulin Epigenetic contributions to oncogenesis including heritable changes in gene expression without DNA sequence changes Genetic screening indications for family history of breast cancer and ovarian cancer Huntington's disease (autosomal dominant) and genetic counseling before testing Maple syrup urine disease (autosomal recessive) requiring both genes of a pair to be abnormal Hemophilia A (X-linked recessive) with carrier mothers and 50% risk in male offspring 8. Stress Response and Adaptation Allostasis as the process of achieving stability through physiologic change Walter B. Cannon's homeostasis concept as a stable coordinated physiologic internal environment achieved through processes that oppose change Hans Selye's General Adaptation Syndrome (GAS) with the first stage being the alarm stage Sympathetic nervous system stimulation manifesting as increased heart rate, pupil dilation, bronchial dilation, and increased blood pressure (fight-or-flight response) Parasympathetic nervous system responses including pupil constriction, bronchial constriction, and decreased blood pressure Stress and illness increasing glycogenolysis and insulin resistance Posttraumatic stress disorder (PTSD) with hypervigilance and obsessive behaviors Stress response affecting multiple body systems including endocrine, cardiovascular, and immune systems 9. Hematologic System Pathophysiology Erythrocytes as the most abundant cells in the blood Neutrophils accounting for the highest percentage of white blood cells (60-70%) Eosinophils with membrane-bound granules and phagocytic activity Neutrophils as the predominant phagocyte of early inflammation Basophils containing preformed granules of vasoactive amines Monocytes maturing into macrophages Platelets releasing biochemical mediators of inflammation Spleen as the main site of hematopoiesis in the fetus Leukocytosis following splenectomy Lymph nodes enlarging during infection due to rapid lymphocyte division Bone marrow as the site of red blood cell production after birth Pluripotent stem cells capable of differentiating into any tissue type Colony-stimulating factors (CSF) participating in hematopoiesis Methemoglobin as an unstable type of hemoglobin that cannot bind with oxygen Erythrocytes containing the greatest proportion of total body iron Transferrin delivering recycled iron from macrophages to bone marrow Erythropoietin produced in the kidneys Hypoxia stimulating erythropoietin secretion Spleen as the site of erythrocyte removal by macrophages after 120 days Calcium as the electrolyte needed for normal platelet functioning Iron, vitamin B12, and folic acid needed for erythropoiesis Decreased thrombopoietin causing low platelet count in newborns Fibrin as the end product of the clotting cascade Plasmin mediating fibrinolysis Thrombin necessary for platelet aggregation phase of platelet degranulation Normal leukocyte count: 5,000-10,000/mm³ Erythrocytes carrying oxygen due to biconcave shape, reversible deformability, and hemoglobin content Hematological aging changes including decreased total serum iron, decreased total iron-binding capacity, and decreased intestinal iron absorption Hemoglobin molecules carrying four oxygen molecules Anisocytosis as variation in erythrocyte size Congenital intrinsic factor deficiency causing pernicious anemia Hypochromic erythrocytes with abnormally low hemoglobin concentration Hyperdynamic circulatory state as compensation for reduced circulating erythrocytes Peripheral vasoconstriction as adaptation to heavy menses blood loss Increased rate and depth of breathing as respiratory compensation for increased oxygen demand Macrocytic, normochromic anemia with normal hemoglobin in vitamin B12 and folate deficiencies Defective DNA synthesis causing macrocytic, normochromic anemia Vitamin B12 and folate deficiencies causing defective erythrocytes that die prematurely Sideroblastic anemia with high iron, bilirubin, and transferrin and low hemoglobin and hematocrit Pernicious anemia caused by absence of intrinsic factor Gastrectomy procedure increasing risk for vitamin B12 deficiency anemia Heart failure as cause of death in pernicious anemia Alcoholism as greatest risk factor for folate deficiency anemia Schilling test for pernicious anemia involving radioactive cobalt and urine excretion measurement Iron deficiency anemia from chronic gastrointestinal bleeding Hemolytic anemia with yellow appearance to skin and sclera Aplastic anemia caused by stem cell deficiency Posthemorrhagic anemia resulting in death when blood loss exceeds 40% to 49% Polycythemia vera with increased erythrocytes, red face, hands, feet, ears, headache, and drowsiness Chest pain in polycythemia vera due to coronary blood flow affected Increased blood viscosity as cause of polycythemia vera symptoms Therapeutic phlebotomy for polycythemia vera treatment Cerebral thrombosis causing death in 50% of individuals with polycythemia vera within 18 months Polycythemia vera at risk for converting to acute myeloid leukemia Leukocytosis defined as high leukocyte count Eosinophilia caused by parasitic invasion and allergic reactions Infectious mononucleosis with splenomegaly, hepatomegaly, and lymph node enlargement Epstein-Barr virus (EBV) causing infectious mononucleosis Down syndrome associated with increased incidence of leukemia Chemotherapy for acute leukemia Multiple myeloma as neoplasm of B cells Bone destruction causing pain in multiple myeloma Lymphadenopathy with enlarged lymph nodes Hodgkin lymphoma with Reed-Sternberg cells Japan having the lowest risk for Hodgkin lymphoma Night sweats and weight loss as symptoms of Hodgkin lymphoma Epstein-Barr virus (EBV) associated with Burkitt lymphoma Hypersplenism causing sequestered erythrocytes Thrombocytopenia being congenital or acquired Immune thrombocytic purpura (ITP) caused by antibody destruction of platelets Primary thrombocythemia with overproduced platelets Vitamin K deficiency causing impaired blood clotting Liver disease causing clotting problems due to decreased clotting factor production Disseminated intravascular coagulation (DIC) initiated by tissue factor release DIC causing active bleeding after intravascular clotting due to clotting factor depletion Fibrin degradation products (FDPs) elevated in DIC Hereditary hemochromatosis as iron overload disorder 10. Oncologic Pathophysiology Benign lung tumor characteristics including growth by expansion and encapsulation Obesity and cancer risk relationship involving inflammation and hormonal changes Stage IV breast cancer with lung metastases requiring systemic treatment Biotherapy mechanisms of action including stimulating immune response to tumor cells and inhibiting tumor protein synthesis Bone cancer treatment considerations in pediatric patients Colorectal cancer treatment mainstay (surgical resection) Dietary guidelines for colon cancer risk reduction including minimizing fat and maximizing fiber Cancer cachexia with loss of fat and muscle mass due to tumor-induced metabolic changes Chemotherapy treatment for leukemia increasing risk for other cancers Excessive ultraviolet radiation exposure increasing risk for ovarian cancer 11. Cardiovascular System Pathophysiology Atherosclerosis caused by abnormal thickening and hardening of vessel walls Foam cells in fatty streak as macrophages that engulf low-density lipoprotein (LDL) Endothelial injury and inflammation as causes of atherosclerosis Normal blood pressure: systolic less than 120 mm Hg and diastolic less than 80 mm Hg Primary (essential) hypertension with no known cause Risk factors for primary hypertension including family history, high sodium intake, and obesity Rigidity of the aorta causing systolic hypertension with widened pulse pressure Malignant hypertension with rapid onset requiring monitoring for organ damage Orthostatic hypotension with symptoms of dizziness and falls Aneurysm in the thoracic aorta causing difficulty swallowing and shortness of breath Cerebral aneurysm located in the circle of Willis Venous thrombus as detached blood clot Pulmonary embolism most likely originating from deep veins of the leg Raynaud disease requiring avoidance of cold and stress Varicose veins caused by standing up for long periods of time Chronic venous insufficiency with skin hyperpigmentation Superior vena cava syndrome (SVCS) as progressive occlusion of the superior vena cava Coronary artery disease with myocardial ischemia Modifiable risk factors for coronary artery disease including smoking cigarettes Trans fats to avoid in diet counseling for elevated LDL and low HDL Atherosclerosis as most common cause of myocardial ischemia Angina pectoris pain occurring when myocardial oxygen supply falls below demand Prinzmetal angina occurring at rest and with exertion Stable angina with substernal pain relieved by rest ST elevation myocardial infarction requiring oxygen to increase myocardial oxygen supply Unstable angina as impending myocardial infarction Platelet aggregation within atherosclerotic coronary artery causing myocardial infarction Impaired ventricular function after myocardial infarction due to ischemia leading to hypoxic injury and myocardial cell death Acute pericarditis with severe chest pain worsening with respirations or lying down Cardiac tamponade with edema, hepatomegaly, and muffled heart sounds Constrictive pericarditis with fibrosis and calcification of pericardial layers causing decreased cardiac output Rheumatic fever or heart disease causing both stenosis and regurgitation Valvular stenosis with constricted and narrowed valve opening Aortic stenosis with lipoprotein deposition and chronic inflammation Mitral stenosis causing incomplete emptying of the left atrium Aortic regurgitation with backflow of blood into the left ventricle Widened pulse pressure and throbbing peripheral pulses in aortic regurgitation Tricuspid regurgitation in right heart failure with pulmonary hypertension Mitral valve prolapse as most common cardiac valve disease in young women Group A β-hemolytic streptococcus infections causing rheumatic heart disease Antigens binding to valvular lining triggering autoimmune response in rheumatic heart disease Bacteria as cause of infective endocarditis Microorganisms sequestered in fibrin clot making endocarditis difficult to treat Atrial fibrillation with no PR interval and variable QRS rate with rhythm irregularity Left ventricular preload increasing as left heart failure progresses Sympathetic nervous system compensation for decreased cardiac output in left heart failure Untreated hypertension leading to left heart failure Decreased kidney perfusion causing increased resistance in left ventricular failure Pulmonary vascular congestion causing cough and dyspnea in left heart failure Right heart failure caused by increased pulmonary pressure Cor pulmonale in chronic pulmonary disease with elevated pulmonary vascular resistance Significant edema to both lower legs and feet in right heart failure 12. Shock States and Multiple Organ Dysfunction Syndrome Impairment in cellular metabolism caused by inadequate tissue perfusion in shock Decreased adenosine triphosphate (ATP) production from switching to anaerobic metabolism Impaired glucose uptake during shock states Decreased cardiac contractility as primary cause of cardiogenic shock after myocardial infarction Hypovolemic shock with compensatory mechanisms including increased heart rate, vasoconstriction, and movement of interstitial fluid to vascular compartment Neurogenic shock caused by vasodilation from decreased sympathetic stimulation Anaphylactic shock with rapid onset Septic shock requiring infection to progress Fever and septic shock assessment findings Hypotensive state in septic shock leading to multiple organ dysfunction Multiple organ dysfunction syndrome (MODS) in critically ill patients Lungs as first organ to fail in MODS Oxygen supply and demand imbalance in MODS with exhausted reserve 13. Respiratory System Pathophysiology Dyspnea as subjective experience of breathing discomfort Orthopnea as dyspnea when lying flat Kussmaul respirations as rapid, deep breathing in metabolic acidosis Cheyne-Stokes respirations with alternating periods of deep and shallow breathing with apnea Paroxysmal nocturnal dyspnea (PND) in left ventricular failure Decreased carbon dioxide levels in acute pain Cyanosis as bluish skin and mucous membranes Hemoptysis as coughing up bloody secretions Hypoxemia as reduced oxygenation of arterial blood High altitude sickness with confusion, tachycardia, edema, and decreased renal output caused by decreased inspired oxygen Low ventilation-perfusion ratio resulting in shunting Alveolar dead space with alveoli receiving ventilation but no perfusion Respiratory failure with elevated PaCO₂ Pulmonary edema most commonly caused by left-sided heart failure Pink, frothy sputum in pulmonary edema Aspiration of gastric contents causing pneumonia Absorption atelectasis from removal of air from obstructed alveoli Bronchiolitis obliterans as fibrotic process occluding airways after lung transplantation Tension pneumothorax with tracheal deviation and air pressure in pleural cavity exceeding barometric pressure Transudative pleural effusion with watery fluid Empyema with pus in pleural cavity Staphylococcus aureus as most likely cause of empyema Restrictive lung disease with decreased functional residual capacity Pneumoconiosis caused by inhalation of silica, asbestos, and mica Acute respiratory distress syndrome (ARDS) with acute lung inflammation and diffuse alveolocapillary injury Alveolocapillary membrane injury causing massive inflammatory response in ARDS Obstructive pulmonary disease with difficulty expiring air Asthma caused by airway hyperresponsiveness Asthma classified by clinical severity Airway hyperresponsiveness related to exposure to allergen causing mast cell degranulation Airway obstruction in asthma caused by mucus secretion, bronchoconstriction, and airway edema Status asthmaticus with prolonged bronchospasm and severe hypoxemia Chronic bronchitis with closure of airway during expiration caused by thick mucus from hypertrophied glands Cigarette smoke as most likely cause of chronic bronchitis Recurrent pulmonary infections as significant concern in chronic bronchitis Emphysema with loss of elastic recoil causing airway obstruction Alpha-1-antitrypsin deficiency causing emphysema Dyspnea as most common presenting factor of emphysema Air trapping causing increased anterior-posterior chest diameter in emphysema Pneumonia caused by viral or bacterial infections Nosocomial pneumonia acquired during hospitalization Tuberculosis caused by bacterium transmitted through airborne droplets Pulmonary thromboembolism composed of blood clot Highest risk for pulmonary embolism in 72-year-old male recovering from hip replacement surgery Pulmonary hypertension from obstruction to pulmonary blood flow Shock and death as complications of massive pulmonary embolism Chest pain and shortness of breath before treatment of pulmonary embolism Prevention of deep vein thrombosis formation to prevent pulmonary embolism Cigarette smoking as greatest impact on development of lung cancer Non-small cell carcinoma requiring adjunctive radiation and chemotherapy Chest pain, tachycardia, and tachypnea in pulmonary embolism Idiopathic pulmonary arterial hypertension (IPAH) with fatigue, dyspnea, and jugular vein distension Pulmonary hypertension indicated by mean pulmonary artery pressure above 25 mm Hg