N305 Exam 2 Study Notes | Spring 2026
Chapter 20: Respiratory Inflammation & Infection
Key Term
- Expectoration: The process of coughing up sputum from the airways.Tuberculosis (TB)
- Definition: Caused by Mycobacterium tuberculosis, a resilient bacterium that can remain dormant in the body as latent TB for years. TB affects 2 billion people worldwide and is a lifelong infection.
- Symptoms:
- Chronic cough
- Hemoptysis: Coughing up blood — hallmark symptom
- Fever and night sweats
- Weight loss, fatigue
- Treatment:
- Antimicrobial medications in combination therapy for long-term use (prevents drug resistance)
- Adequate hydration and nutrition
- Antipyretics for fever
- Extra to Know:
- Diagnosed via Mantoux tuberculin skin test (PPD) or IGRA blood test
- Immunosuppressed individuals (e.g., HIV+) are highly susceptible to active TB
- Transmitted by droplet infection — sneezing, coughing, or hand contact
- Multi-drug resistant TB (MDR-TB) is a major global concernAcute Sinusitis
- Symptoms:
- Headache, malaise, fever
- Stuffy/runny nose, sore throat, earache
- Treatment:
- Decongestants, antihistamines, saline sprays, heated mists
- Antibiotics (if bacterial cause confirmed)Lung Abscess
- Definition: A localized area of purulent (pus-filled) exudate in the lung, resulting in tissue necrosis and a central area of liquefaction/cavity formation.
- Symptoms:
- Foul-smelling sputum (hallmark — caused by anaerobic bacteria)
- Cough, chills, fever, weight loss
- Treatment:
- Antibiotics (prolonged course)
- Surgical drainage if necessary
- Extra to Know:
- Often caused by aspiration of oral bacteria
- Right middle/lower lobes most commonly affected (vertical right bronchus = easier path for aspiration)Respiratory Assessment Basics:
- Mucociliary apparatus: Cilia + mucus-secreting goblet cells trap pathogens — smoking paralyzes it.
- Hemoptysis: Blood in sputum; always a red-flag symptom.
- Normal SpO2: >= 95%; pulse oximeter measures peripheral oxygen saturation.
- Tachypnea: Fast breathing; Bradypnea: Slow breathing (CO2 accumulates).
- Spinal injury at/above C4: Diaphragm paralysis -> respiratory failure (requires mechanical ventilation).
- Right bronchus is more vertical -> aspiration most often goes to right middle/lower lobe.
Chapter 21: Restrictive & Obstructive Pulmonary Disorders
Key Distinction:
- Obstructive: Increased resistance to airflow (COPD, asthma)
- Restrictive: Reduced lung expansion (pleural effusion, pulmonary fibrosis).Pleural Effusion
- Definition: Abnormal fluid collection within the pleural space/cavity. The pleural space is normally a vacuum with only a thin film of surfactant. Excess fluid compresses lung tissue and prevents full expansion.
- Symptoms:
- Dyspnea (difficulty breathing)
- Increased respiratory rate (tachypnea)
- Pleuritic chest pain (sharp, worsens with breathing)
- Treatment:
- Thoracentesis: Needle insertion into pleural space to drain fluid.
- Treatment of underlying cause (heart failure, malignancy, infection).ARDS — Acute Respiratory Distress Syndrome
- Definition: Occurs in critically ill patients — commonly those in intensive care for another diagnosis (sepsis, trauma, pneumonia). Characterized by widespread alveolar damage, severe hypoxemia, and bilateral lung infiltrates.
- Symptoms:
- Severe respiratory distress
- Coarse, loud crackles across both lungs (bilateral)
- Tachycardia, elevated blood pressure
- Severe hypoxemia unresponsive to supplemental oxygen alone
- Treatment:
- Mechanical ventilation (low tidal volumes to protect lungs)
- Prone positioning (improves oxygenation)
- Supportive care (fluids, nutrition, treatment of underlying cause)
- Warning: ARDS is a complication, not a primary diagnosis. Always identify the underlying trigger. Carries very high mortality.Asthma
- Definition: A chronic inflammatory disorder that causes reversible bronchospasm due to bronchial hyperreactivity. Unlike COPD, airflow obstruction is reversible with treatment.
- Symptoms:
- Wheezing (high-pitched sound on exhalation)
- Cough (often worse at night)
- Dyspnea and chest tightness
- Triggers — Exacerbated By:
- Environmental allergens (pollen, dust, pet dander, mold)
- Exercise, cold air, smoke, strong odors
- Respiratory infections
- Symptoms may be worse at night
- Treatment:
- SABA (Short-Acting Beta-2 Agonist) — rescue inhaler e.g. albuterol for acute attacks
- ICS (Inhaled Corticosteroids) — long-term control/anti-inflammatory
- LABA/LAMA — long-acting bronchodilators for maintenance
- Leukotriene receptor antagonists (e.g., montelukast)
- Pathophysiology Extra:
- Inflammation -> mast cell activation -> histamine + leukotriene release -> bronchoconstriction + excess mucus
- Th2 immune response drives allergic component
- Chronic inflammation leads to airway remodeling — structural changes that worsen over time.
Chapter 22: Renal Disorders
Key Kidney Functions:
- Acid-base balance — regulates hydrogen ions and bicarbonate
- Waste elimination — filters urea, creatinine, uric acid, drug metabolites via urine
- Hypoxia -> stimulates erythropoietin secretion -> bone marrow produces more RBCs
- Low blood volume -> stimulates renin secretion -> activates RAAS -> raises BP
- Vitamin D synthesis and activation -> affects calcium absorption
- Renal glucose threshold: ~180 mg/dL — glucose spills into urine above this level
- Normal urine output: Minimum 400 mL/day. Less than this = oliguria, indicating renal compromise.Acute Kidney Injury (AKI)
- Definition: Reversible failure of the kidneys, classified into three types based on mechanism of injury:
- Type: Prerenal
- Mechanism: Decreased blood flow/perfusion to kidney
- Common Causes: Hemorrhage, shock, dehydration, heart failure
- Type: Intrinsic (Intrarenal)
- Mechanism: Direct damage to kidney tissue
- Common Causes: Nephrotoxic drugs (NSAIDs, aminoglycosides), infection, acute tubular necrosis (ATN)
- Type: Postrenal
- Mechanism: Obstruction of urine outflow
- Common Causes: BPH (prostate enlargement), tumors, kidney stones.
- Acute Tubular Necrosis (ATN): Most common cause of AKI. Ischemia/hypoxia damages nephron tubule cells, which slough into the lumen, blocking urine flow and worsening injury. Reversible if caught early.Chronic Kidney Disease (CKD)
- Definition: Irreversible, progressive disease process — unlike AKI, kidney damage is permanent.
- Risk Factors:
- Family history of kidney disease
- Age > 60
- Hypertension (HTN) — damages renal blood vessels over time
- Diabetes Mellitus (DM) — most common cause in the US
- Systemic Lupus Erythematosus (SLE)
- African American heritage (highest incidence)
- CKD Consequences:
- Anemia — deficient erythropoietin production
- Bone disease — deficient vitamin D activation -> decreased calcium
- Fluid and electrolyte imbalances
- Uremia — toxic waste buildup in blood
- End-stage renal disease (ESRD) requires dialysis or transplant.Renal Laboratory Values
- Lab Test: BUN (Blood Urea Nitrogen)
- Normal Range: 5-20 mg/dL
- Clinical Significance: Elevated with decreased GFR or dehydration. BUN alone is NOT a reliable indicator of renal function.
- Lab Test: Creatinine
- Normal Range: 0.5-1.5 mg/dL
- Reliable indicator of kidney function — rises when GFR falls. Preferred over BUN alone.
- Lab Test: GFR
- Normal Range: 90-120 mL/min
- Directly reflects renal function; decreases 1 mL/min per year after age 30.
- Urinalysis: Note: Crystals in urine are NOT normal — they indicate nephrolithiasis (kidney stones). Know basic reasons for urinalysis: suspected infection, monitoring renal disease, evaluating hematuria or proteinuria.
Chapter 23: Urological Disorders
Obstructive Uropathy & BPH
- Definition: Obstruction is one of the most common pathophysiological problems in the urinary tract. Any blockage prevents urine flow and can lead to hydronephrosis (swollen, fluid-filled kidney) and eventual kidney failure.
- BPH — Benign Prostatic Hyperplasia
- Common obstructive disorder in men over 60
- Overgrowth of cells in the prostate gland surrounding and compressing the urethra
- Symptoms:
- Hesitancy (difficulty starting urine stream)
- Weak or interrupted urine stream
- Urinary frequency, urgency, nocturia
- Incomplete bladder emptying
- Extra — Hydronephrosis:
- Distension of renal pelvis and calyces due to obstruction
- If prolonged -> irreversible kidney damage
- Caused most often by kidney stones (in young adults) or BPH (older men).Urinary Tract Infection (UTI)
- Epidemiology:
- More common in women (shorter urethra, closer to rectum)
- Women aged 20-40 are 30x more likely than men to get a UTI
- Urinary catheters significantly increase risk for both fungal and bacterial UTI
- Causes:
- Obstruction -> stagnant urine (bacteria proliferate)
- Sexual activity, improper hygiene, urinary catheters
- Symptoms:
- Dysuria: Pain/burning on urination
- Urgency: Sudden strong urge to urinate
- Hematuria: Blood in urine
- Frequency, cloudy urine, foul odor
- Critical: Lower UTI does NOT cause fever. If fever is present with UTI symptoms, suspect pyelonephritis (upper UTI — infection has spread to the kidney). This changes treatment urgency significantly.
- Treatment:
- Antibiotics (e.g. nitrofurantoin, trimethoprim-sulfamethoxazole)
- Increased fluid intake
- Remove/replace urinary catheter if possible.
Chapter 24: Endocrine Disorders
Feedback System:
- High hormone -> pituitary stops releasing tropic hormone (negative feedback).
- Low hormone -> pituitary releases more tropic hormone to stimulate the gland.Hypothyroidism
- Definition: Insufficient levels of thyroid hormones T3 and T4. Results in slowed metabolism throughout the body.
- Symptoms:
- Puffy face (myxedema)
- Feeling cold (decreased metabolism/heat generation)
- Weight gain
- Low energy, fatigue, depression
- Elevated LDL cholesterol
- Constipation, dry skin, hair loss, bradycardia
- Monitoring — TSH (Thyroid Stimulating Hormone)
- TSH Level:
- High TSH: Pituitary working overtime to stimulate sluggish thyroid (Hypothyroidism)
- Low TSH: Pituitary backs off — thyroid producing too much (Hyperthyroidism)
- Treatment:
- Thyroid hormone replacement — levothyroxine (Synthroid)
- Extra:
- T4 is mostly inactive; converted to active T3 in peripheral tissues
- Iodine is required for thyroid hormone synthesis — worldwide iodine deficiency is a leading cause.Adrenal Insufficiency — Addison's Disease
- Definition: Primary adrenal insufficiency = Addison's Disease. Decreased ACTH from the pituitary OR dysfunction of the adrenal gland itself, resulting in insufficient cortisol and aldosterone.
- Symptoms:
- Weakness, lethargy, easy fatigue
- Hypotension (especially orthostatic)
- Anorexia, nausea, vomiting
- Skin hyperpigmentation (primary Addison's)
- Hyponatremia, hyperkalemia (from aldosterone deficiency)
- Treatment:
- Daily replacement of glucocorticoid (e.g., hydrocortisone)
- Daily replacement of mineralocorticoid (e.g., fludrocortisone)
- Increased doses needed during illness or stress (stress dosing).Cushing's Syndrome — Hyperadrenalism
- Definition: Excess cortisol secreted by the adrenal gland. Often caused by a pituitary ACTH-secreting tumor (Cushing's disease) or prolonged corticosteroid medication use.
- Symptoms — Very Distinct, Know These!:
- Weight gain of the face, trunk, and abdomen (central/truncal obesity)
- Easy bruising and poor wound healing