Study Guide
Key Terms and Concepts
Here are the basic definitions and concepts you should know for each term, organized by system
or related processes.
Urinary System Terms
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Afferent Arteriole: Vessel carrying blood to the glomerulus.
Efferent Arteriole: Vessel carrying blood away from the glomerulus.
Bowman’s Capsule: Structure surrounding the glomerulus where filtration begins.
Glomerulus: Capillary network where blood is filtered.
Glomerular Filtration Rate (GFR): Rate at which blood is filtered in the kidneys.
Nephron: Functional unit of the kidney responsible for filtration, reabsorption, and
excretion.
Loop of Henle: U-shaped portion of the nephron that establishes a concentration gradient
for water reabsorption.
Proximal Convoluted Tubule: First section of the nephron, involved in reabsorption of
water, ions, and nutrients.
Distal Convoluted Tubule: Last nephron segment before collecting duct; involved in
selective reabsorption and secretion.
Collecting Duct: Tubule where final adjustments to urine composition are made.
Vasa Recta: Capillaries parallel to the Loop of Henle that maintain osmotic gradient.
Renal Corpuscle: Combination of the glomerulus and Bowman’s capsule.
Renal Cortex: Outer portion of the kidney containing nephrons.
Renal Medulla: Inner kidney region where loops of Henle are located.
Renal Pelvis: Central collecting area for urine before it exits the kidney.
Renal Artery/Vein: Blood vessels delivering and removing blood from the kidney.
Urine: Waste product of the kidneys excreted via the urinary tract.
Bladder: Organ for urine storage.
Ureter: Tube carrying urine from the kidney to the bladder.
Urethra: Tube through which urine exits the body.
Urinary Tract Infection (UTI): Infection in any part of the urinary system.
Vasopressin (ADH): Hormone regulating water reabsorption in the kidney.
Gastrointestinal (GI) System Terms
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Mouth: Site of ingestion and beginning of digestion.
Salivary Glands: Exocrine glands producing saliva to begin digestion.
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Amylase: Enzyme in saliva that breaks down carbohydrates.
Esophagus: Tube carrying food from mouth to stomach.
Epiglottis: Flap preventing food from entering the trachea during swallowing.
Stomach: Organ for mechanical digestion and initial protein digestion via enzymes and
acid.
Chyme: Partially digested food leaving the stomach.
Small Intestine: Primary site of nutrient digestion and absorption, consisting of the
duodenum, jejunum, and ileum.
Duodenum: First section where most chemical digestion occurs.
Jejunum: Middle section specializing in nutrient absorption.
Ileum: Final section absorbing bile salts and vitamins.
Colon (Large Intestine): Absorbs water and forms feces.
Rectum: Final segment for fecal storage before defecation.
Defecation Reflex: Neural reflex controlling bowel movements.
Liver: Produces bile, detoxifies substances, and processes nutrients.
Gallbladder: Stores and concentrates bile for fat digestion.
Bile Salts: Components of bile aiding in fat emulsification.
Pancreas: Secretes digestive enzymes and bicarbonate ions into the duodenum.
Gastric Glands: Stomach glands secreting acid and enzymes.
Parietal Cells: Stomach cells secreting hydrochloric acid (HCl).
Chief Cells: Stomach cells secreting pepsinogen, which becomes pepsin to digest
proteins.
Protease: General term for enzymes breaking down proteins.
Lipase: Enzyme breaking down fats.
Lacteal: Lymphatic capillaries in villi that absorb dietary fats.
Enterocyte: Absorptive cells lining the small intestine.
Rugae: Folds in the stomach allowing expansion.
Mucus: Secretion protecting and lubricating the GI tract.
Sphincters: Muscle rings controlling passage of food or waste between sections of the GI
tract.
General Physiological Terms
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Autoregulation: Ability of organs (e.g., kidney) to maintain constant function despite
changes in blood pressure.
Excretion: Removal of waste products from the body.
Secretion: Active transport of substances into tubules or GI tract.
Filtration: Passive movement of substances from blood into the nephron.
Reabsorption: Return of filtered substances from the nephron to the blood.
Portal Systems: Venous systems connecting capillary beds, such as the hepatic portal
system.
Core Concepts to Understand
1. Processes in the GI Tract
o Motility: Peristalsis (wave-like contractions) and segmentation (mixing
movements).
o Digestion: Breakdown of food (mechanical vs. chemical).
o Secretion: Release of digestive enzymes and fluids.
o Absorption: Uptake of nutrients into the bloodstream or lymph.
2. Kidney and Nephron Functions
o Path of blood: Renal artery → Afferent arteriole → Glomerulus → Efferent
arteriole → Peritubular capillaries → Renal vein.
o Path of filtrate: Bowman’s capsule → Proximal tubule → Loop of Henle →
Distal tubule → Collecting duct → Renal pelvis → Ureter.
o Filtration, reabsorption, and secretion processes in urine formation.
o Countercurrent Exchange: Mechanism in the Loop of Henle and vasa recta to
concentrate urine.
3. Hormonal Regulation
o Aldosterone: Stimulates sodium reabsorption, increasing water retention.
o Vasopressin (ADH): Promotes water reabsorption in the collecting ducts.
4. Digestive Enzymes and Functions
o Amylase (carbohydrates), protease (proteins), lipase (fats), and bicarbonate ions
(neutralize stomach acid).
5. Hepatic Portal System
o Blood from GI tract organs flows to the liver for detoxification and nutrient
processing.
Tips for Studying:
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Create flow diagrams for processes (e.g., blood/filtrate flow in kidneys or digestion
pathways).
Use flashcards for terms and enzyme functions.
Compare active vs. passive transport mechanisms.
Practice labeling kidney and GI tract diagrams.