Structure and Function of the Digestive System

Vocabulary

accessory organ

any one of the organs of the digestive system that assists the process of digestion by secreting enzymes

alimentary canal

continuous tube that runs through the body from the mouth to the anus

bolus

rounded mass of food formed in the mouth when food is mixed with saliva

brush border

series of cells with microvilli

chief cell

cell that secretes pepsinogen, the precursor for pepsin, an enzyme that breaks down proteins in the stomach

chyme

mixture of partially broken down food, stomach acids, and enzymes

deglutition

transport of food from the mouth to the stomach

dentition

set of teeth

enteroendocrine cell

cell that secretes hormones such as gastrin

esophageal glands

secrete mucus to lubricate the esophagus and facilitate food transport

esophagus

muscular tube that transports food from the pharynx to the stomach

goblet cell

simple columnar epithelial cell that secretes mucus to protect the mucous membrane

lacteal

lymphatic vessel in the small intestine that absorbs digested fat

lumen

inside region of a tubular organ

mastication

process of using the teeth to mechanically digest food

microvillus (plural, microvilli)

small projections on the apical surface of epithelial cells

mucosa

innermost layer that lines the interior of the alimentary canal of the digestive system

mucous neck cell

cell in the neck, or upper part of the gastric pits, that secretes mucus

muscularis externa

layer of smooth muscle fibers in the alimentary canal of the digestive system

palate

arch at the roof of the mouth

parietal cell

cell that secretes hydrochloric acid (HCl) and intrinsic factor

peristalsis

waves of smooth muscle contraction in the walls of the alimentary canal that moves food through

pharynx

passageway at the back of the oral and nasal cavities for both food and air

rugae

series of ridges produced by folding of the wall of an organ to allow for stretch

segmentation

coordinated contraction of circular muscle that moves chyme in a back and forth movement

serosa

outermost layer of the alimentary canal of the digestive system made mostly of connective tissue that provides structural support

sphincter

band of muscle tissue used to regulate food moving from one organ to another

submucosa

layer of connective tissue that underlies the mucus layer in the alimentary canal of the digestive system

uvula

small piece of tissue that hangs in the back of the throat