Digestive System

Polysaccharides

Carbohydrates made up of long chains of monosaccharide units.

Disaccharides

Carbohydrates composed of two monosaccharides.

Oligosaccharides

Carbohydrates that contain a small number of monosaccharides.

Monosaccharides

The simplest form of carbohydrates, absorbed directly by the intestine.

Glycogen

The stored form of glucose in the body.

Fat

A form of stored energy in the body derived from excess glucose.

Amino acids

The end products of protein digestion.

Triglycerides

The main form of stored fat in the body.

Phospholipids

Lipids that are a major component of cell membranes.

Cholesterol

A type of lipid essential for cell membrane structure and function.

Alimentary canal

The continuous tube from the mouth to the anus responsible for digestion.

Mesentery

A double-layered membrane that helps hold digestive organs in place.

Lesser omentum

The structure that connects the liver to the stomach.

Hepatic portal vein

Transports nutrients from the digestive organs to the liver.

Circular and longitudinal layers

The two layers of muscle in the alimentary canal.

Three layers (circular, longitudinal, and oblique)

The number of muscle layers found in the stomach.

Upper esophageal, lower esophageal, pyloric, ileocecal, anal

The five sphincters of the alimentary canal.

Maxilla and palatine bones

The structures that form the hard palate.

Palatine, pharyngeal, and lingual tonsils

The three pairs of tonsils found in the mouth.

Parotid, submandibular, and sublingual glands

The three pairs of major salivary glands.

1,500 ml

The approximate amount of saliva produced daily.

Enamel

The hardest substance in the body found on teeth.

Pulp cavity

The innermost part of the tooth containing blood vessels and nerves.

Up to 32 teeth

The typical number of teeth adults have.

Peristalsis

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

Transport food from the mouth to the stomach

The primary functions of the esophagus.

Esophageal hiatus

The opening through which the esophagus passes through the diaphragm.

Stratified squamous epithelium

The type of epithelium that lines the esophagus.

Simple columnar epithelium

The type of epithelium that lines the stomach.

Mucus

The substance that protects the stomach lining from its acidic environment.

Hydrochloric acid (HCl) and intrinsic factor

The substances secreted by parietal cells in the stomach.

Absorption of vitamin B12

The necessity of intrinsic factor.

Pepsinogen

The enzyme secreted by chief cells to aid in protein digestion.

Gastrin

The hormone secreted by enteroendocrine cells in the stomach.

Stimulate HCl production in the stomach

The function of gastrin.

Chyme

The semi-liquid mixture of food and digestive juices in the stomach.

Pyloric sphincter

The sphincter through which chyme enters the small intestine.

Duodenum, jejunum, ileum

The three parts of the small intestine.

In the small intestine

Where most nutrient absorption occurs.

Villi

Small, fingerlike projections that increase surface area for absorption in the small intestine.

Lacteal

A lymphatic vessel in each villus that absorbs fats.

Microvilli

Microscopic projections on the surface of epithelial cells in the small intestine.

Into the duodenum

Where the bile duct and main pancreatic duct empty.

Cholecystokinin (CCK)

The hormone that relaxes the sphincter to release bile.

Peyer's patches

Lymphoid tissue found in the small intestine.

Gallbladder

The structure that stores bile.

Hepatic and cystic ducts

The liver ducts that form the common bile duct.

Portal triad

A grouping of a bile duct, hepatic artery, and hepatic portal vein found in the liver.

Glycogen

What the liver converts excess glucose into for storage.

Vitamins A, D, E, K

The four fat-soluble vitamins stored in the liver.

Bile salts

Compounds derived from cholesterol that help emulsify fats.

Enterohepatic circulation

The process through which bile salts are recycled.

Pancreas's exocrine function

The production of digestive enzymes.

Pancreas’s endocrine function

The production of insulin and glucagon.

Salivary amylase

The enzyme that digests starch in the mouth.

Pancreatic amylase

The enzyme that continues starch digestion in the small intestine.

In the stomach with pepsin

Where protein digestion begins.

Trypsin

The enzyme that helps digest protein in the small intestine.

Emulsification

The process of breaking down fats into small droplets.

Pancreatic lipase

The enzyme that digests fats.

Absorbing water and electrolytes

The primary function of the large intestine.

Haustra

Pouches in the large intestine formed by muscle tone.

Transverse colon

The part of the colon located between the right and left colic flexures.

Before the rectum in the lower abdomen

The location of the sigmoid colon.

Cecum

The structure to which the appendix is attached.

Smooth muscle

The type of muscle that forms the internal anal sphincter.

Skeletal muscle

The type of muscle that forms the external anal sphincter.

Bacteria that produce vitamin K and other beneficial substances

What the colon contains to help prevent infection.

Zymogens

Inactive forms of digestive enzymes.

Pylorus

The part of the stomach that controls chyme release into the duodenum.

Segmentation

Rhythmic contractions in the intestine to mix food.

Emulsify fats

The primary function of bile.

Secretin and CCK

The hormones that trigger the release of pancreatic juice.

Nuclease

The enzyme that digests nucleic acids.

Neutralize stomach acid in the small intestine

The role of bicarbonate in pancreatic juice.

Submucosa

The layer of the GI tract that contains blood vessels and lymphatics.

Myenteric plexus

The structure located between the layers of the muscularis externa.