The organ system that processes food, extract nutrients from it and eliminates the residue.
Also can be called "disassembly line".
The uptake of nutrient molecules into the epithelial cells of the digestive tract and then into the blood or lymph.
a series of hydrolysis reactions that break dietary macromolecules into their monomers (residues): polysaccharide into monosaccharides, proteins into amino acids, fats into monoglycerides and fatty acids and nucleic acids into nucleotides.
a muscular tube extending from mouth to anus, measuring about 9m (30 ft) long in the cadaver.
Also known as "alimentary canal".
Mucosa (mucous membrane)
lining the lumen consists if an inner epithelium, loose connective tissue and a thin layer of smooth muscle.
think layer of loose CT containing blood vessels, lymphatic vessels, a nerve plexus, and in some places, glands that secrete lubricating mucus into the lumen.
two layers of smooth muscle near the outer surface of the digestive tract; the inner layer encircles the tract and the outer layer runs longitudinally.
enteric nervous system
a nervous network in the esophagus, stomach, and intestines that regulated digestive tract motility, secretion, and blood flow. Composed of 2 network: submucosal plexus and myenteric plexus.
submucosal (Meissner) plexus
in submucosa. it controls glandular secretion of mucosa and the movements of muscularis mucosae.
myenteric (Auerbach) plexus
parasympathetic ganglia and nerve fibers between the two layers of the muscularis interna. It controls peristalsis and other contractions of muscularis externa.
connective tissue sheets that loosely suspend the stomach and intestines from the abdominal wall.
sheet of tissue that continues beyond the digestive organs. it hangs freely in the abdominal cavity or it may attach to the ventral abdominal wall.
a ventral mesentery that extends from the lesser curvature of the stomach to the liver.
hangs from the left inferior margin (greater curvature) of the stomach and loosely covers the small intestine like an apron.
the mesentery (folds of peritoneum) that attach the colon to the posterior wall of the abdominal cavity.
when an organ lies against the posterior body wall and is covered by peritoneum on the anterior side only.
What control the motility and secretion of the digestive tract?
motility and secretion of the digestive tract are controlled by neural, hormonal, and paracrine mechanisms.
What hormone does the digestive tract produce?
the digestive tract produce gastrin and secretin and paracrine secretion such as histamine and prostaglandins.
Mouth (oral or buccal cavity)
Its function include ingestion, taste and other sensory responses to food, chewing, chemical digestion, swallowing, speech and respiration.
chemical messengers secreted into bloodstream, and stimulate distant parts of the digestive tract.
muscular, bulky, but remarkably agile and sensitive organ. it manipulates food between teeth while it avoids being bitten, it can extract food particles from the teeth after a meal and it sensitive enough to feel a stray hair in a bite of food.
a V-shaped row of papillae that mark the boundary between the body and root of the tongue.
contained entirely within the tounge, produce the relatively subtle tongue movements of speech.
with origins elsewhere and insertions in the tounge, produce the stronger movements of food manipulation. Includes genioglossus, hyoglossus, palatoglossus and styloglossus.
separating the oral cavity from the nasal cavity, making it possible to breath while chewing food.
a spongy texture and is composed mainly of skeletal muscle and glandular tissue, but no bone.
a bony socket in the alveolar ridge that holds a tooth. form a joint called a gomphosis between the tooth and bone.
lined by alveolus. A modified periosteum whose collagen fibers penetrate into the bone on one side and into the tooth on the other.
cells of the cementum (cementocytes)
are scattered more or less randomly and occupy tiny cavities similar to the lacunae of bone.
Cells of the dentin (odontoblasts)
line the pulp cavity and have slender processes that travel through tiny parallel tunnels in the dentin.
the passage in the root of a tooth through which its nerve and blood vessels enter the pulp cavity.
breaks food into smaller pieces to be swallowed and exposes more surface to the action of digestive enzymes.
moistens the mouth, digests a little starch and fat, cleanses the teeth, inhibits bacterial growth, dissolves molecules so they can stimulate the taste buds, and mostens food and binds particles together to aid in swallowing.
enzyme that is activated by stomach acid and digests fat after the food is swallowed.