Alterations in Digestive Function, Fluid, Electrolyte, and Acid-Base Balance

Flashcards covering alterations in digestive function, nutrition, gastrointestinal disorders, fluid and electrolyte balances, acid-base imbalances, and congenital genetic conditions.

Nutrition

The process of ingesting and utilizing nutrients for energy, growth, repair, and tissue maintenance.

Metabolism

The sum of all chemical processes occurring within the human body.

Catabolism

The metabolic pathway that breaks down complex molecules and gives off energy.

Anabolism

The metabolic pathway that builds complex molecules and requires energy input.

Essential Nutrients

Nutrients that must be consumed in the diet because the body is unable to produce them.

Water Survival Limit

The estimated maximum timeframe a person can survive without water, specified as $3\,\text{days}$.

Caloric Value of Proteins

The energy yield provided by proteins, equal to $4\,\text{kcal/g}$.

Essential Amino Acids Mnemonic (A=Arginine)

PVT TIM HALL (or DUT TIM HALL), which lists the amino acids that must be obtained from diet.

Non-essential Amino Acids

Amino acids produced in the body that provide nitrogen necessary for cellular growth and repair.

Complete Proteins

Dietary proteins containing all essential amino acids, primarily sourced from animal foods.

Incomplete Proteins

Dietary proteins lacking one or more essential amino acids, primarily sourced from plant foods.

Caloric Value of Carbohydrates

The energy yield provided by carbohydrates, equal to $4\,\text{kcal/g}$.

Simple Carbohydrates

Carbohydrates composed of one or two sugar molecules (e.g., white rice, pasta, bread) that digest easily and rapidly.

Complex Carbohydrates

Carbohydrates composed of long branching chains of sugar molecules (e.g., fiber, potatoes, fruits, wheat) that take longer to digest.

Fiber Intake Recommendation

The daily intake recommendation for dietary fiber, specified as $25\text{--}30\,\text{g/day}$.

Insoluble Fiber

Plant fiber and cellulose broken down by gut bacteria that adds bulk to stool to speed up movement.

Soluble Fiber

Fiber that dissolves in water to keep the digestive tract and stool hydrated while slowing digestion.

Caloric Value of Lipids

The energy yield provided by fats and lipids, equal to $9\,\text{kcal/g}$.

Essential Fatty Acids

Fatty acids required by the body that must be ingested, specifically linoleic acid and linolenic acid.

Saturated Fats

Fats containing no double bonds that remain solid at room temperature, such as butter and lard.

Unsaturated Fats

Plant-based oils containing one or more double bonds that remain liquid at room temperature.

Triglycerides

Lipids composed of a glycerol molecule (a 3-carbon chain) attached to 3 fatty acid chains.

Compound Lipids

Lipid structures bound to non-lipid components, including phospholipids and glycolipids.

Sterols

Ring-based lipid structures, such as cholesterol and bile salts.

Fat-Soluble Vitamins

Vitamins A, D, E, and K, which are stored in the liver.

Water-Soluble Vitamins

Vitamins B and C, which are excreted by the body in urine when present in excess.

Major Minerals

Minerals required by the body in amounts greater than $5\,\text{g}$, including sodium, calcium, potassium, phosphorus, magnesium, and sulfur.

Optimum Daily Allowances (ODA)

The precise intake amount of a nutrient required for optimal body functioning.

Adult Caloric Requirement

The recommended baseline caloric intake for adults, given as $30\text{--}40\,\text{kcal/kg}$.

Macronutrient Distribution Ratios

The recommended daily intake ratios: $50\text{--}60\%$ carbohydrates, $10\text{--}20\%$ proteins, and $30\%$ fats.

Anorexia Nervosa

An eating disorder marked by severe caloric restriction, purging, weight $>25\%$ below normal, bradycardia, hypotension, and loss of muscle mass.

Bulimia Nervosa

An eating disorder marked by binge-purge cycles at normal body weight, causing electrolyte imbalances and erosion of dental enamel.

Marasmus

A severe deficiency of all nutrients in infants under age 1 with body weight $<60\%$ of normal, leading to liver failure and $50\%$ mortality without treatment.

Kwashiorkor

Severe protein deficiency occurring in children $>18\,\text{months}$ after weaning, causing hypoalbuminemia, reduced blood colloid osmotic pressure, ascites, and edema.

Altered Nutrition

Malnutrition resulting from inadequate nutrient intake, absorptive surface damage, genetic defects, malabsorption syndromes, or hypermetabolism.

Thyroid Trace Mineral

Iodine, an essential trace mineral required for proper thyroid gland function.

Mallory-Weiss Syndrome

Longitudinal tears in the distal esophagus caused by forceful, repeated vomiting that lead to bleeding into the stomach.

Hiatal Hernia Type 1

An enlarged esophageal opening in the diaphragm through which portions of the stomach slide upward.

Hiatal Hernia Type 2

A severe hernia where a second opening forms in the central tendon of the diaphragm.

GERD Pain Timing

Substernal pain occurring $30\text{--}50\,\text{minutes}$ postprandially (after eating).

Barrett's Esophagus Pharmacotherapy

Treatment utilizing Proton Pump Inhibitors (PPIs) and $\text{H}_2$ antagonists.

Chronic Gastritis Types

Categorized as Type A (autoimmune) and Type B (non-autoimmune).

Zollinger-Ellison Syndrome

A gastrinoma causing excessive oversecretion of gastrin and stomach acid.

Gastric Carcinoma Common Site

Stomach cancer that develops most frequently along the lesser curvature.

Helicobacter pylori

A bacterium that burrows into the gastric mucosa and buffers local acids, affecting $50\%$ of the global population and requiring 2 antibiotics plus a PPI to treat.

Stomach Lining Direct Absorption

Substances absorbed directly across the stomach mucosal lining, specifically aspirin and alcohol.

Ulcerative Disease Pain Pattern

Burning, gnawing, or cramping pain near the xiphoid process that improves after consuming carbohydrates.

Irritable Bowel Syndrome (IBS) Diagnostic Criterion

A collection of signs and symptoms exacerbated by stress and diet that must last $>12\,\text{weeks}$.

Crohn's Disease

An autoimmune inflammatory bowel disease in the small intestine causing scar tissue, obstructions, and decreased nutrient absorption.

Ulcerative Colitis

An autoimmune inflammatory bowel disease in the large intestine where deep layer penetration into blood vessels causes blood in stool (NSAIDs are contraindicated).

Halitosis

Bad breath caused by decomposing or rotten food trapped in GI outpouches.

Phenylketonuria (PKU)

An inability to break down phenylalanine to tyrosine, impairing CNS development and myelin formation.

Niemann-Pick Disease

A lysosomal storage disease resulting in sphingolipid accumulation in somatic cells (Type A is fatal by $18\,\text{months}$).

Tay-Sachs Disease

A lysosomal storage disease caused by a defect in the HEXA gene, leading to ganglioside accumulation in neurons, developmental delays, and death by age $4$.

Cholelithiasis

A gallbladder disorder characterized by the presence or formation of gallstones.

Hepatitis A Transmission

Infection transmitted via food-borne or fecal-oral routes that causes a short-duration illness and resolves spontaneously.

Hepatitis B and C Management

Infections transmitted through close contact, treated with Antiretroviral Therapy (ART) and interferon.

Chronic Viral Hepatitis Etiology

Chronic viral liver infection caused specifically by HBV, HCV, and HDV.

Fatty Liver (Steatosis)

Accumulation of fat deposits inside liver cells causing liver enlargement, which can progress to cirrhosis.

Alcoholic Hepatitis

Liver inflammation and tissue necrosis associated with alcohol consumption, presenting with rapid onset of jaundice.

Cirrhosis Pathophysiology

A nodular liver appearance caused by increased hepatocyte counts and scar tissue blockages that promote ongoing inflammation.

Male Body Fluid Compartments

Total body water equals $60\%$ of weight ($40\%$ intracellular fluid, $20\%$ extracellular fluid).

Female Body Fluid Compartments

Total body water equals $50\%$ of weight ($30\%$ intracellular fluid, $20\%$ extracellular fluid).

Interstitial Fluid Share

The fraction of extracellular fluid contained within the interstitial space, equal to $80\%$.

Hydrostatic Pressure

The outward force (e.g., blood pressure) pushing water out of capillaries into interstitial fluid.

Osmotic Pressure

The inward pulling force exerted by plasma proteins (like albumin) drawing water into blood vessels.

Isotonic Solution

A solution with equal extracellular solute concentration, causing no net water movement or cell volume change.

Hypotonic Solution

A solution with decreased extracellular solute concentration, causing water to enter cells so they swell and lyse.

Hypertonic Solution

A solution with increased extracellular solute concentration, drawing water out of cells so they shrivel and crenate.

Dependent Edema

Interstitial fluid accumulation occurring in lower body regions directly influenced by gravity.

Edema: Capillary Filtration Pressure Mechanism

Increased capillary hydrostatic pressure forcing fluid out, caused by venous obstruction (e.g., pregnancy).

Edema: Capillary Osmotic Pressure Mechanism

Decreased plasma proteins (hypoalbuminemia) reducing the pulling force into capillaries, seen in liver failure and malnutrition.

Edema: Capillary Permeability Mechanism

Increased vessel leakiness triggered by histamine, inflammatory mediators, tissue injury, or mast cell activation.

Edema: Lymphatic Drainage Mechanism

Obstruction of lymph nodes preventing fluid drainage, caused by cancer in the U.S. and parasitic infections globally.

Hypervolemia

Expansion of extracellular fluid volume due to organ failure, excessive steroids, cirrhosis, or fluid over-replacement.

Hypervolemia Homeostatic Controls

Decreased aldosterone, reduced ADH secretion to increase urine output, and natriuretic peptide secretion to excrete sodium.

Hypovolemia Compensations

Renin-Angiotensin-Aldosterone system activation, vasoconstriction, and increased cardiac contraction force.

Hemorrhagic Loss Classifications

Body weight loss percentages for hemorrhage: Mild ($2\%$), Moderate ($5\%$), and Severe ($8\%$).

Dehydration Features

Extracellular fluid loss leaving hypertonic remaining fluid and dehydrated cells, manifesting as oliguria, thirst, headache, seizures, and coma.

Water Intoxication (Hypotonic Hypovolemia)

Extracellular fluid dilution following fluid replacement without salt, causing fluid to enter cells and produce swelling, cramps, fatigue, and muscle weakness.

Normal Extracellular Sodium Level

The normal extracellular fluid concentration of $\text{Na}^+$, equal to $142\,\text{mEq/L}$.

Normal Intracellular Sodium Level

The normal intracellular fluid concentration of $\text{Na}^+$, equal to $10\,\text{mEq/L}$.

Normal Extracellular Chloride Level

The normal extracellular fluid concentration of $\text{Cl}^-$, equal to $103\,\text{mEq/L}$.

Normal Extracellular Bicarbonate Level

The normal extracellular fluid concentration of $\text{HCO}_3^-$, equal to $28\,\text{mEq/L}$.

Hyponatremia Threshold & Symptoms

Plasma $\text{Na}^+ < 135\,\text{mEq/L}$ presenting with 'low and slow' symptoms: N/V, tachycardia, hypotension, muscle weakness, and confusion.

Hypernatremia Threshold & Symptoms

Plasma $\text{Na}^+ > 145\,\text{mEq/L}$ presenting with intense thirst, weight gain, tachycardia, hypertension, and edema.

Hypokalemia Threshold & Symptoms

Blood $\text{K}^+ < 3.0\,\text{mEq/L}$ causing dizziness, hypotension, muscle weakness, arrhythmias, and intestinal distension.

Hyperkalemia Threshold & Symptoms

Blood $\text{K}^+ > 5.0\,\text{mEq/L}$ caused by renal failure or iatrogenic factors, leading to cardiac arrest, abdominal cramping, and flaccidity.

Hypochloremia Threshold

Blood chloride concentration $< 97\,\text{mEq/L}$, linked with hyponatremia, hypokalemia, and metabolic alkalosis.

Hyperchloremia Threshold

Blood chloride concentration $> 107\,\text{mEq/L}$, presenting with deep tachypnea, weakness, and metabolic acidosis.

Hypocalcemia Threshold & Symptoms

Blood $\text{Ca}^{2+} < 9.0\,\text{mg/dL}$ producing increased muscle tone, cramping, twitching, anxiety, and seizures.

Hypercalcemia Threshold

Blood $\text{Ca}^{2+} > 10.3\,\text{mg/dL}$ causing reduced muscle cell contraction, weakness, fatigue, N/V, and arrhythmias.

Hypophosphatemia Threshold

Blood phosphate concentration $< 3.0\,\text{mg/dL}$, causing weakness, tremors, paresthesias, bone deformity, and weight loss.

Hyperphosphatemia Threshold

Blood phosphate concentration $> 4.5\,\text{mg/dL}$, which occurs alongside hypocalcemia and causes no symptoms on its own.

Hypomagnesemia Threshold & Symptoms

Blood $\text{Mg}^{2+} < 1.3\,\text{mEq/L}$ producing 'high everything': increased muscle tone, twitching, seizures, and cardiac arrhythmias.

Hypermagnesemia Threshold & Symptoms

Blood $\text{Mg}^{2+} > 2.1\,\text{mEq/L}$ producing 'low everything': hypotension, areflexia, flaccidity, bradycardia, and respiratory depression.

Bicarbonate Buffering Equation

The reaction $\text{H}_2\text{O} + \text{CO}_2 \rightleftharpoons \text{H}_2\text{CO}_3 \rightleftharpoons \text{H}^+ + \text{HCO}_3^-$, catalyzed by carbonic anhydrase.

Anion Gap Calculation

Calculated as $\text{Na}^+ - (\text{Cl}^- + \text{HCO}_3^-) = 12$, where an gap $> 20$ indicates metabolic acidosis.

Teratogens

Environmental agents, drugs, pathogens, hormones, or radiation that alter gene expression and cause embryonic or fetal harm during pregnancy.

Spina Bifida Etiology

A developmental neural tube defect caused by maternal folic acid deficiency resulting in failure of the neural tube to fuse posteriorly.