Digestive System Study Guide - Vocabulary Flashcards

Vocabulary flashcards covering key terms and definitions from the Digestive System study notes.

Alimentary canal

The continuous tube from the mouth to the anus through which digestion and absorption occur.

Mouth

Entrance to the digestive tract where mechanical chewing and chemical saliva digestion begin.

Pharynx (Throat)

A passageway for food from the mouth to the esophagus during swallowing.

Esophagus

Muscular tube that transports food to the stomach via peristaltic waves.

Stomach

Sac where mechanical churning and chemical digestion occur, with acid and enzymes.

Small intestine

Long tube where most of digestion and nutrient absorption take place.

Large intestine (colon)

Absorbs water and electrolytes; forms and stores stool.

Cecum

First section of the large intestine; connects to ileum; contains the appendix.

Ascending colon

First portion of the colon that travels upward on the right side.

Transverse colon

Section of the colon that crosses the abdomen from right to left.

Descending colon

Section of the colon that travels downward on the left side.

Sigmoid colon

S-shaped part of the colon leading to the rectum.

Rectum

Final section of the large intestine, stores feces before elimination.

Anus

External opening at the end of the GI tract controlled by sphincters.

Duodenum

First section of the small intestine where chyme mixes with bile and pancreatic juice.

Jejunum

Middle section of the small intestine where most nutrient absorption occurs.

Ileum

Last section of the small intestine where bile acids and vitamin B12 are absorbed.

Lumen

The hollow interior of a tubular structure like the GI tract.

Mucosa

Innermost lining of the GI tract that secretes mucus and absorbs nutrients.

Submucosa

Layer beneath the mucosa containing blood vessels, nerves, and glands.

Muscularis

Muscular layer of the GI tract responsible for peristalsis; usually circular and longitudinal layers (and oblique in the stomach).

Serosa

Outer protective layer (visceral peritoneum) of the GI tract.

Mechanical digestion

Physical breakdown of food (e.g., chewing, churning).

Chemical digestion

Enzymatic breakdown of food polymers into smaller molecules.

Enamel

Hard, mineralized outer layer of teeth; the hardest substance in the body.

Salivary amylase

Enzyme in saliva that begins starch digestion.

Bolus

Chewed, moistened mass of food ready to be swallowed.

Epiglottis

Flap that covers the trachea during swallowing to prevent aspiration.

Peristalsis

Coordinated muscular contractions that move contents through the GI tract.

Pepsin

Protein-digesting enzyme in the stomach (works best in acidic conditions).

Chyme

Partially digested food after it leaves the stomach and enters the small intestine.

Pancreas

Gland that secretes digestive enzymes (lipase, amylase, proteases) and bicarbonate; also secretes insulin and glucagon.

Lipase

Pancreatic enzyme that digests fats.

Trypsin

Pancreatic enzyme that digests proteins.

Insulin

Hormone that lowers blood glucose; produced by the pancreas.

Liver

Organ that produces bile, processes nutrients, stores glycogen and vitamins.

Bile

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

Gallbladder

Organ that stores and concentrates bile.

Bilirubin

Yellow pigment from red blood cell breakdown; processed by the liver and excreted in bile.

Jaundice

Yellowing of skin and eyes due to elevated bilirubin when the liver can't clear it.

Pancreatic Duct

Duct that carries pancreatic juices to the duodenum.

Common Bile Duct

Duct that carries bile from the liver and gallbladder to the duodenum.

Common Hepatic Duct

Duct that drains bile from the liver, merging to form the common bile duct.

Cystic Duct

Duct that carries bile to and from the gallbladder.

Rugae

Folds in the stomach lining that allow expansion.

Cardiac region (cardia)

Upper portion of the stomach near the esophagus.

Lesser Curvature

Smaller inner curve of the stomach.

Greater Curvature

Larger outer curve of the stomach.

Pyloric Sphincter

Valve controlling passage from the stomach to the duodenum.

Fundus

Upper, dome-shaped part of the stomach above the esophageal opening.

Body of the stomach

Main central region of the stomach between fundus and pylorus.

Oblique muscles (stomach)

An additional muscle layer in the stomach aiding digestion.

Circular muscles (stomach)

Muscle layer that mixes contents by constricting rings.

Longitudinal muscles (stomach)

Muscle layer that runs lengthwise along the stomach.

Parotid Gland

Largest salivary gland near the ear.

Submandibular Gland

Salivary gland beneath the jaw.

Sublingual Gland

Salivary gland under the tongue.

Mesentery

Peritoneal fold that attaches intestines to the posterior abdominal wall and houses vessels.

Greater Omentum

A fatty peritoneal fold that drapes over the intestines from the stomach.

Absorption

Process of taking digested nutrients into the blood or lymph.

Villi

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

Celiac disease

Autoimmune damage to intestinal villi leading to malabsorption.

Scurvy

Vitamin C deficiency causing symptoms like gum disease and poor healing.

Rickets

Vitamin D deficiency causing soft, weak bones in children.

Gastroenterologist

Physician who specializes in diseases of the gastrointestinal tract and liver.