Patho: EXAM 1 (F/E) Study Guide

Patho Exam 1

What is edema?

Excess fluid in the interstitial space (between cells and tissues).

What are the 4 main mechanisms that cause edema?

↑ Capillary hydrostatic pressure; ↓ Plasma oncotic pressure; ↑ Capillary permeability; Lymphatic obstruction

Why does increased capillary hydrostatic pressure cause edema? give example

Too much pressure pushes fluid out of capillaries into tissues (e.g., heart failure, venous obstruction).Heart failure and venous obstruction both back up blood, raising venous pressure and pushing fluid out of capillaries into tissues → edema. left side heart failure →pulmonary edema, right side heart failure → peripheral edema.

Why does decreased plasma oncotic pressure cause edema? give example

Low plasma proteins (like albumin) reduce the “pull” of fluid back into capillaries (e.g., liver disease, malnutrition).

Why does increased capillary permeability cause edema? give example

Vessels become “leaky” so proteins and fluid escape into tissues (e.g., inflammation, burns, allergic reactions).

Why does lymphatic obstruction cause edema? give example

Lymph system can’t drain fluid and proteins, so fluid accumulates (e.g., tumor, post-mastectomy lymphedema).

What are the clinical signs of edema?

WISP: Weight gain, Impaired wound healing, Swelling , pitting edema

What hormone conserves only water and concentrates urine?

ADH (antidiuretic hormone).

What hormone saves sodium and water but excretes potassium?

Aldosterone. To reabsorb sodium, the kidney uses a sodium–potassium exchange pump (Na⁺/K⁺ transport). As sodium is pulled back into the blood, potassium is pushed out into urine.

What hormones promote sodium and water excretion to lower blood volume?

ANP (atrial natriuretic peptide): released by atria when stretched from high blood volume/pressure. BNP (brain natriuretic peptide): released by ventricles in heart failure. Both cause sodium & water excretion → ↓ blood volume & ↓ BP.

What is the normal sodium range?

135–145 mEq/L.

What is hyponatremia, and what causes it?

Na⁺ <135; SHDV caused by excess water (SIADH- Syndrome of Inappropriate Antidiuretic Hormone, heart failure release ADH) or sodium loss (diuretics, vomiting).

What are the S/S of hyponatremia?

Neuro focused: CEWS: Confusion, edema,, weakness, seizures. (Hyponatremia = low Na⁺ outside (dilution or Na⁺ loss) → outside fluid dilute → water moves into cells → brain swelling.

What is hypernatremia, and what causes it?

Na⁺ >145; DDS → Dehydration (water loss), Diabetes insipidus (ADH problem → kidneys can’t hold water because they don’t respond to ADH→ water loss in urine), Sodium gain (too much Na⁺ intake/retention).

What are the S/S of hypernatremia?

Neuro + dehydration signs: TADS = Thirst, Agitation, Dry mucous membranes, Seizures.(Hypernatremia = high Na⁺ outside (hypertonic) → outside fluid concentrated → water moves out of cells → brain shrinkage).

mnemonic for hyponatremia (cause and s/s)

SHVD (SIADH, Heart failure - release ADH, Vomiting - vomit sodium/potassium/chloride, Diuretic) + CEWS neuro focused (confusion, edema, weakness, seizure) low Na+ outside → water moves inside → brain swells

mnemonic for hypernatremia (cause and s/s)

DDS (Diabetes inspidus - kidney doesnt react to ADH, water loss through urine, Dehydration - sodium concentrates, Sodium intake/retention + TADS (Thirst, Agitation, Dry mucous membrane, Seizure) High Na+ outside hypertonic → water moves outside → brain shrink

What is the normal potassium range?

3.5–5.0 mEq/L.

What is hypokalemia, and what causes it?

K⁺ <3.5; DVDI: caused by diuretics, vomiting - you vomit sodium/potassium/chloride, diarrhea - intestine is rich in K+ and bicarbonate HCO3- so you lose lots of stool, you lose K+, insulin therapy - tells K+ to move from blood into cells like glucose so blood K+ drops

What are the S/S of hypokalemia?

WAU: Weakness, Arrhythmias (U wave on ECG). cramps,

What is hyperkalemia, and what causes it?

K⁺ >5.0; RAC: Renal failure - kidney cant excrete K+, acidosis - H⁺ (acid) into cells → K⁺ moves out of cell into the blood, cell lysis.

What are the S/S of hyperkalemia?

WAT: Weakness, arrhythmias (peaked T waves, wide QRS).

What is the normal calcium range?

8.5–10.5 mg/dL.

What is hypocalcemia, and what causes it?

Ca²⁺

What are the S/S of hypocalcemia?

Tetany, tingling, positive Chvostek’s/Trousseau’s signs, seizures.

What is hypercalcemia, and what causes it?

Ca²⁺ >10.5; caused by hyperparathyroidism, bone metastases.

What are the S/S of hypercalcemia?

Weakness, kidney stones, bone pain, arrhythmias.

What are signs of dehydration?

DTHP = Dry mucous membranes, tachycardia, hypotension, poor skin turgor.

What are signs of hypovolemia (low fluid volume)?

WOT = Weight loss, orthostatic hypotension, tachycardia.

What are signs of hypervolemia (excess fluid volume)?

WEP = Weight gain, edema, pulmonary congestion.

What are common clinical effects of electrolyte disturbances?

Na⁺ → Neuro changes (confusion, seizures); K⁺ → Cardiac arrhythmias; Ca²⁺ → Muscle weakness or spasms.