N717 Patho Final study guide

oncogenes

Require 1 activating mutation (1 allele hit) to drive cell proliferation and survival (KRAS, BRAF, MYC)

tumor suppressors/ 2 hit-hypothesis

• Germline mutation = first hit already present

• One additional mutation → cancer risk ↑ (not guaranteed cancer)

ex) BRCA

Ectopic ACTH (Cushing's Syndrome) & labs

non-pituitary tumors inappropriately secrete ACTH

• hypokalemia, hypertension (HTN), metabolic alkalosis

tumor lysis syndrome (TLS)

A metabolic emergency triggered by massive cell lysis 

↑ K+ (Hyperkalemia), ↑ Phos (Hyperphosphatemia), ↓ Ca2+ (Hypocalcemia).

superior vena cava (SVC) syndrome & symptoms

structural emergency causing venous obstruction

• Venous obstruction: Facial, neck, and upper extremity swelling

hypovolemic shock (CO, SVR, preload, symptoms)

• cold shock - volume loss

• ↓ CO, ↑ SVR, ↓ Preload

• Cool extremities, low JVP, narrow pulse pressure, hx bleeding/ fluid loss

cardiogenic shock (CO, SVR, preload, symptoms)

• cold shock - pump failure (decr contractility)

•  ↓ CO, ↑ SVR, ↑ Preload

wet + cold HF symptoms

cardiogenic shock d/t pump failure (decr contractility)

• WET: Elevated JVP and edema (fluid isn’t being pumped out)

• COLD: cool extremities (decr CO)

tx: inotropes & hemodynamic support

obstructive shock (CO, SVR, symptoms)

• cold shock- physical obstruction (RV infarct, PE, cardiac tamponade)

• ↓ CO, ↑ SVR

• JVD, clear lungs, hypotension

RV infarct symptoms

• Decr LV preload → hypotension + JVD; lungs remain clear

PE symptoms

↑ RV afterload → ↓ LV preload → hypotension

septic shock (CO, SVR, preload)

incr CO, decr SVR, decr preload
warm extremities, hypotension

Decr in nitric oxide causes…

incr SVR —> hypertension

QTc prolongation >500 causes…

delayed ventricular repolarization → Torsades de Pointes (TdP) risk 

1. metabolic acidosis —> __ compensate

2. resp acidosis —> __ compensate

1. lungs

2. kidneys (retain bicarb)

DKA —>

(metabolic acidosis) Kussmaul respirations

insulin & potassium

Insulin → activates Na/K ATPase → K shifts INTO cells (lowering blood potassium levels)

potassium in acidosis vs. alkalosis

• In acidosis → hyperkalemia. 

• In alkalosis → hypokalemia.

wave patterns hyperkalemia vs. hypokalemia

• Hyperkalemia: tall, peaked T waves, QRS widening and sine-wave patterns 

• Hypokalemia: U waves, flat T waves

pre-renal AKI mechanism & finding

• low perfusion

  • FeNA <1%

intrinsic (ATN) AKI mechanism & finding

• tubular damange

• muddy brown casts

post-renal AKI mechanism & finding

• obstruction

  • hydronephrosis

geriatric & Cr + CKD
normal Cr ~0.6-1.3

Elderly → low muscle mass → normal creatinine can hide CKD

obstructive lung disease

• Obstructive Pattern: Characterized by airway narrowing and expiratory flow limitation.

  • ↓ FEV1/FVC ratio (< 0.70)

    • Examples: Asthma, COPD

restrictive lung disease

• Restrictive Pattern: Characterized by decreased lung compliance and inability to fully expand.

  • ↓ TLC (Total Lung Capacity)

    • Examples: Pulmonary fibrosis, sarcoidosis

asthma diagnosis

FEV1 improves >12% after bronchodilator

how does portal HTN —> ascities

Portal HTN → Splanchnic vasodilation → ↓ effective circulating volume → RAAS activation → Na/H₂O retention → ascites

hepatic encephalopathy chain

Ammonia → astrocytes → glutamine → swelling → confusion

Jaundice + pale stool + dark urine

billary obstruction (cholestatic)

ACA stroke

leg weakness, apathy

MCA

face/ arm weakness ± aphasia

PCA

visual deficits

ischemic stroke core vs. penumbra

• Core = dead

• Penumbra = salvageable

MS + heat —>

Uhthoff phenomenon (temporary symptom flare)

axonopathy vs. myelinopathy

• Axonopathy → ↓ amplitude

  • inner wires broken = less electricity reaching end (amplitude) 

• Myelinopathy → ↓ conduction speed

  • No insulation = travels slowly

IL-8

Neutrophil Recruitment  (directs neutrophils to the exact site of injury or infection)

IL-6

Acute Phase Response (CRP, fibrinogen)

TNF-a & IL-1

Systemic Inflammation & Shock (drives fever)

bandemia (incr bands) —>

acute bacterial infection

aspelenia (host risk factor) —>

risk for encapsulated organisms

TB survives by living inside macrophages —>

granulomas

pregnancy & resp

Pregnancy: Progesterone → ↑ respiratory drive → mild respiratory alkalosis

edema = ___ pressure

capillary hydrostatic pressure (HF)

impetigo vs. cellulitis vs. contact dermatitis

• Impetigo = superficial (epidermis) 

• Cellulitis = deeper (dermis, subcutis) 

• Contact dermatitis = Type IV hypersensitivity (48-72 hr T-cell delayed reaction)

bone: Estrogen ↓ —>

↑ osteoclast activity (demolition crew)

bone: steroids —>

↓ osteoblasts (building crew) → poor healing

geri homeostenosis

Reduced physiologic reserve → Small stressor → large decompensation

geri & dyphendydramine —>

delirium