Anatomy Chapter 14 Quiz #3

Ingestion

food placed into the mouth; voluntary

Propulsion

overall process of moving food through the digestive tract from mouth to rectum, including voluntary swallowing and involuntary muscle movements

Peristalsis

specific, involuntary, wave-like contraction and relaxation of smooth muscles that cause movement; mechanism that drives propulsion

Absorption

transport of digested end products from the lumen of SI to the blood lymph; typically occurs in small intestine

Defecation

elimination of indigestible residues in the form of feces

Deglutition

the act of swallowing

Buccal phase

first, voluntary stage of deglutition (swallowing), where tongue manipulates a food bolus against the hard palate and pushes it backward into the oropharnyx

pharyngeal=esophageal phase

involuntary ~1 second reflex (stimulated by the oral/buccal phase) that moves the bolus from the oropharynx to the esophagus, elevating the palate and closing the airway.

Esophageal phase is the final involuntary, peristaltic transport of the bolus through the esophagus into the stomach.

Gastric juice

mixture of pepsinogen and HCI

Gastrin

hormone that stimulates gastric secretions, especially hydrochloric acid release

Heartburn

burning pain in the chest caused by acid reflux-the backward flow of stomach acid into the esophagus

Esophagitis

inflammation, irritation, or swelling of the esophagus lining

Hiatal hernia

occurs when the upper part of the stomach pushes up into the chest cavity through a small opening (hiatus) in the diaphragm

Pepsinogen

breaks down proteins in the stomach; made by chief cells

Pepsin

an enzyme capable of digesting proteins in an acid pH; breaks down proteins into smaller peptides

Emesis

vomiting; rapid, forceful expulsion of gastric contents through the mouth

Brush border enzymes

break down sugars into simple sugars; complete protein digestion

Pancreatic juice

a secretion of the pancreas containing enzymes for digestion of all food categories

Pancreatitis

inflammation of the pancreas

Defecation reflex

involuntary, autonomic response that empties the rectum when feces cause distention (stretch) in the rectal wall

Diarrhea

passing of loose or watery stools daily, resulting from a disruption in the small/large intestine’s ability to absorb water, electrolytes, and nutrients

Constipation

infrequent or difficult passage of hard, dry stool, resulting from excessive water absorption in the colon due to slow transit, or dysfunction in the rectum/pelvic floor

Mass movements

powerful, infrequent peristaltic contractions in the large intestine (transverse to sigmoid colon) occurring 3-4 times daily, usually triggered by the gastrocolic reflex after meals

Haustral contractions

slow, segmenting, and involuntary muscular movements of large intestine, occurring every 25-30 minutes to mix chyme and facilitate water/electrolyte absorption

Segmentation

vital mechanical digestion process where circular smooth muscles in the intestines contract rhythmically, creating a back and forth churning motion (localized contraction)

Secretin

a polypeptide hormone produced by S cells in the duodenal mucosa (small intestine) that regulates digestion by stimulating the pancreatic and biliary bacarbonate-rich fluid secretion