Digestive, Urinary, and Fluid/Electrolyte - Vocabulary Flashcards (Ch. 23-25)

Vocabulary flashcards covering key terms related to the digestive system (Ch. 23), urinary system (Ch. 24), and fluid/electrolyte/acid-base (Ch. 25).

Mechanical digestion

Physical breakdown of food (e.g., chewing) that increases surface area for enzymes.

Chemical digestion

Enzymatic breakdown of food by secretions into absorbable units.

Mastication

Chewing; the mechanical digestion that begins in the mouth.

Deglutition

Swallowing; movement of a bolus from mouth to esophagus.

Uvula

Structure that helps prevent food/drink from entering the nasal passages.

Epiglottis

Flap that covers the trachea during swallowing to prevent food entry.

Lower esophageal sphincter (cardiac sphincter)

Muscular valve between esophagus and stomach that prevents reflux.

GERD

Gastroesophageal reflux disease; chronic reflux of stomach contents into the esophagus.

Stomach

Organ where mechanical digestion (churning) and chemical digestion occur; forms acidic chyme.

Intrinsic factor

Stomach-produced protein essential for vitamin B12 absorption in the small intestine.

Rugae

Accordion-like folds in the stomach lining that allow expansion.

Fundus

Dome-shaped upper portion of the stomach.

Body (stomach)

Main central region of the stomach.

Pylorus

Distal region of the stomach leading to the duodenum.

Pyloric sphincter

Muscular valve regulating gastric emptying into the duodenum.

Chyme

Acidic, semi-fluid mass of partly digested food formed in the stomach.

Duodenum

First part of the small intestine; site of chyme mixing with bile and pancreatic juice.

Jejunum

Second portion of the small intestine; primary site of nutrient absorption.

Ileum

Final portion of the small intestine; absorbs bile acids and B12.

Villi

Finger-like projections in the small intestine that increase absorption surface.

Lacteal

Lymphatic vessel in a villus that transports fats.

Small intestine absorption

Primary site of nutrient absorption via villi/microvilli with capillaries and lacteals.

Microvilli

Tiny projections on enterocytes that further increase absorptive surface.

Large intestine (colon)

Absorbs water/electrolytes; forms stool; includes cecum and colon.

Cecum

First part of the large intestine; appendix attached.

Appendix

blind-ended tube attached to the cecum; immune function; can become inflamed.

Hepatic (liver)

Metabolic processing; produces bile; also called hepatic.

Gallbladder

Stores and concentrates bile; releases bile into the small intestine.

Bile

Digestive fluid that emulsifies fats; produced by the liver and stored in the gallbladder.

Pancreas

Gland that secretes digestive enzymes and bicarbonate into the small intestine.

Bicarbonate

Alkaline HCO3- electrolyte that neutralizes stomach acid in the small intestine.

Villi and absorption (overview)

Structures that maximize nutrient absorption in the small intestine.

Peritoneal membranes / Mesentery

Peritoneum; membranes that anchor and suspend digestive organs.

Four digestive tract layers

Mucosa, submucosa, muscularis externa, serosa—their roles in protection, secretion, and movement.

Peristalsis

Wave-like muscle contractions that move contents through the digestive tract.

Digestive tract order

Esophagus → stomach → small intestine (duodenum, jejunum, ileum) → large intestine (cecum, colon, rectum).

Renal artery

Main artery supplying blood to the kidney.

Renal vein

Main vein draining filtered blood from the kidney back to circulation.

Nephron

Functional unit of the kidney; ~1 million per kidney; forms urine.

Bowman’s capsule

Cup-like structure surrounding the glomerulus that collects filtrate.

Glomerulus

Capillary network where filtration occurs; not part of Bowman's capsule.

Renal tubules

Proximal convoluted tubule, loop of Henle (descending/ascending), distal convoluted tubule, collecting duct.

Glomerular filtration

First step of urine formation; filtrate includes water/solutes; RBCs/proteins are too large.

Tubular reabsorption

Second step; substances are reabsorbed from filtrate back into the blood.

Creatinine

Waste product; elevated levels indicate reduced kidney function.

Tubular secretion

Third step; substances are secreted from blood into tubules for elimination.

Aldosterone

Hormone that increases sodium reabsorption and helps regulate blood volume/electrolytes.

ADH (vasopressin)

Hormone that increases water reabsorption in collecting ducts, affecting water balance.

Oliguria

Very low urine output.

Polyuria

Excessive urine production.

Dehydration

Fluid deficit; output exceeds intake; volume depletion.

Edema

Excess fluid accumulation in tissues from imbalances in intake/output or circulation.

Hypernatremia / Hyponatremia

Abnormal sodium levels (high/low).

Hyperkalemia / Hypokalemia

Abnormal potassium levels (high/low).

pH (normal range 7.35-7.45)

Measure of hydrogen ion concentration; normal blood pH is 7.35-7.45.

Acidosis

Condition where blood pH is below 7.35.

Alkalosis

Condition where blood pH is above 7.45.

Buffer system (bicarbonate buffer)

System that maintains pH by buffering H+; main components are HCO3-, CO2, and H+.

Respiratory vs metabolic acid-base disorders

Disorders classified by cause: breathing-related (respiratory) or non-respiratory (metabolic).

Respiratory acidosis

Low pH due to hypoventilation and CO2 retention.

Respiratory alkalosis

High pH due to hyperventilation and CO2 loss.

Metabolic acidosis

Low pH due to metabolic causes (e.g., diabetes, diarrhea).

Metabolic alkalosis

High pH due to metabolic causes (e.g., vomiting).

Gastric reflux

Backflow of stomach contents into the esophagus; GERD involves this chronic process.