Digestive System Flashcards

Vocabulary flashcards for the digestive system lecture.

Main organs of the digestive system

Mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anus.

Accessory organs of the digestive system

Teeth, tongue, gallbladder, salivary glands, liver, and pancreas.

Ingestion

Occurs in the mouth.

Propulsion

Movement of food (Peristalsis).

Digestion

Breakdown of food to be ready for absorption.

Mechanical digestion

Prepares food for chemical digestion (chewing, churning food in stomach).

Chemical digestion

Complex molecules broken down to simple chemical components by enzymes.

Absorption

Transport of digested nutrients to blood and lymph.

Defecation

Elimination of indigestible substances as feces.

Peritoneum

A serous membrane.

Visceral peritoneum

Surrounds digestive organs.

Parietal peritoneum

Lines the body wall.

Peritoneal cavity

A slit-like potential space.

Mesentery

A double layer of peritoneum that holds organs in place, stores fat, and provides a route for vessels and nerves.

Mesocolon

Related to the large intestine.

Peristalsis

Waves of contraction and relaxation of musculature in organ walls.

Segmentation

Rhythmic local constrictions of the intestine that mix food with digestive juices.

Mucosa

Innermost layer of the alimentary canal wall.

Submucosa

External to the mucosa; contains blood vessels, lymphatic vessels, and nerve fibers.

Muscularis externa

External to the submucosa; responsible for peristalsis.

Serosa

Outermost layer of the alimentary canal wall; same as the visceral peritoneum.

Borders of oral cavity

Lips, cheeks, palate, tongue.

Lingual frenulum

Secures tongue to floor of mouth.

Deciduous (baby) teeth

20 teeth that first appear at 6 months.

Permanent teeth

32 teeth that erupt by the end of adolescence.

Dental formula

2 incisors, 1 canine, 2 premolars, 3 molars (per quadrant).

Parts of a tooth

Crown, neck, and root.

Layers of a tooth

Enamel, dentin, and pulp cavity.

Enamel

Outer layer of a tooth; hardest tissue in the body.

Dentin

Underlies enamel in a tooth.

Saliva

Complex mixture of water, ions, mucus, and enzymes that moistens mouth, dissolves food chemicals, and wets food.

Major salivary glands

Parotid, submandibular, and sublingual glands.

Parotid duct

Parallel to zygomatic arch (angle of jaw).

Submandibular glands

Lie along medial surface of mandible (under mandible).

Sublingual glands

Under tongue and lie in floor of oral cavity; contain primarily mucus cells.

Cardiac sphincter

Acts to close off the lumen and prevent regurgitation of acidic stomach juices into the esophagus.

Main parts of the stomach

Cardiac region, fundus, body, and pyloric part.

Pyloric sphincter

Valve for stomach and duodenum.

Rugae of mucosa

Mucosal folds in the stomach.

Muscularis externa layers in stomach

Longitudinal, circular, and oblique layer.

Main parts of the small intestine

Duodenum, jejunum, and ileum.

Duodenum

Small C-shaped loop where most chemical digestion occurs.

Jejunum

Most nutrient absorption takes place here.

Ileum

Absorbs most vitamins and minerals.

Main function of the small intestine

Site of the most enzymatic digestion and absorption.

Circular folds

Transverse ridges of mucosa and submucosa.

Villi

Fingerlike projections of the mucosa.

Microvilli

Further increase surface area for absorption.

Main parts of the large intestine

Cecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, and anus.

Cecum

Opening of appendix.

Teniae coli

Thickening of longitudinal muscularis externa in the large intestine.

Haustra

Bumps or puckering created by teniae coli in the large intestine.

Epiploic appendages

Fat-filled pouches of visceral peritoneum in the large intestine.

Right colic (hepatic) flexure

Between ascending and transverse colon.

Left colic (splenic) flexure

Under spleen.

Ileocecal valve

Prevents backflow in the large intestine.

Main function of the large intestine

Absorb water and electrolytes.

Liver capsule

Left and right lobe.

Elements that pass through porta hepatis

Hepatic portal vein, hepatic artery proper and common hepatic duct (bile duct).

Bile production

Emulsification of fats (lipids).

Gallbladder

Contracts and secretes to duodenum by the ducts.

Exocrine function of pancreas

Acinar cells make, store, and secrete enzymes that digest food in the small intestine.

Main pancreatic duct

Joins bile duct to form the hepatopancreatic ampulla which empties into duodenum.

Main cause of peptic ulcer

Caused by helicobacter pylori.