[BIO 142] Lecture Quiz 2 Chapter 24

Borborygmus

A rumbling or gurgling sound made by the movement of fluids and gases in the intestines

Cathartics

Drugs that promote defecation.

Cholelithiasis

The presence of gallstones in the gallbladder.

Cholera

A bacterial infection of the digestive tract that causes massive fluid losses through diarrhea.

Colitis

A general term for a condition characterized by inflammation of the colon

Crohn’s disease

An incurable chronic inflammatory bowel disease that can affect any part of the digestive tract, from the mouth to the anus. The presence of strictures, fistulas, and fissures is common.

Diverticulitis

An infection and inflammation of mucosal pockets of the large intestine (diverticula).

Diverticulosis

The formation of diverticula, generally along the sigmoid colon.

Dysphagia

Difficulty or discomfort in swallowing due to disease.

Esophageal varices

Swollen and fragile esophageal veins that result from portal hypertension.

Fecal occult blood test

Test to check for hidden blood in feces.

Gastrectomy

The surgical removal of the stomach, generally to treat advanced stomach cancer.

Gastroesophageal reflux disease (GERD)

Chronic condition in which the lower esophageal sphincter allows gastric acids to backflow into the esophagus, causing heartburn, acid indigestion, and possible injury to the esophageal lining.

Gastroscope

A fiberoptic instrument inserted into the mouth and directed along the esophagus and into the stomach'; used to examine the interior of the stomach and to perform minor surgical procedures.

Halitosis

Bad breath that may be due to poor oral hygiene, an infection, diabetes, or other disease.

Insoluble fiber

Indigestible plant carbohydrates that do not dissolve in water and pass through the GI tract unchanged. Found in many vegetables and skins of fruits, insoluble fiber speeds up the passage of material in the GI tract. Individuals consuming diets rich in insoluble fiber decrease their risk for developing diabetes, atherosclerosis, and colorectal cancers, among other diseases.

Irritable bowel syndrome (IBS)

A common disorder affecting the large intestine, accompanied by cramping, abdominal pain, bloating, gas, diarrhea, and constipation.

Pancreatic cancer

Malignancy of the pancreas that does not cause symptoms in its early stages, leading to late detection and a survival of only four percent.

Periodontal disease

A loosening of the teeth within the alveolar sockets caused by erosion of the periodontal ligaments by acids produced through bacterial action.

Polyps

Small growths with a stalk protruding from a mucous membrane that is usually benign.

Pulpitis

An infection of the pulp of a tooth; treatment may involve a root canal procedure

Pyloric stenosis

A condition in which the muscle of the lower end of the stomach enlarges and prevents food from entering the small intestine. It occurs most often babies under 6 months.

Pylorospasm

Spasm of the pyloric sphincter, accompanied by pain and vomiting.

Root canal

Removal of the alveolar nerve in a severely damaged tooth.

Soluble Fiber

Indigestible plant carbohydrates found in beans, oats, and citrus fruits that dissolve in water when eaten, forming a gel within the digestive tract to slow the passage of material. Diets rich in soluble fiber lower blood cholesterol levels.

Facts About Gastrin Duodenum

• Secreted by G cells

• Stimulates acid production by parietal cells and gastric motility in the stomach

Facts About Gastric Inhibitory peptide (GIP)

• Stimulated by incompletely digested proteins arriving in the stomach

• GIP inhibits Gastrin release

• Stimulates the release of insulin from the pancreas islets

Facts About Secretin Hormone

• Stimulated by chyme reaching the duodenum

• Increase the secretion of alkaline buffers by the pancreas

• Stimulates the secretion of bile by the liver

• Reduces gastric motility and gastric secretory rates

Facts About Cholecystokinin (CCK)

• Stimulated by chyme reaching the duodenum

• Relaxes the hepatopancreatic sphincter (Sphincter of Oddi)

• Stimulates ejection of bile and alkaline pancreatic buffers into the duodenum

• Inhibits gastric activity & reduce feelings of hunger

Facts About Vasoactive Intestinal Peptide (VIP)

• Stimulated by chyme reaching the duodenum

• Dilates regional intestinal capillaries which is an effective mechanism to take absorbed nutrients throughout the body

• Inhibits acid production in the stomach

Facts About Enterocrinin

• Stimulated by chyme reaching the duodenum

• Stimulates alkaline mucus production in the submucosal glands

Mechanism of HCL Secretion

1. CO2 enters the parietal cell from the interstitial fluid

2. With the help of carbonic anhydrase, CO2 + H2O in the cell fuse to form H2CO3 (carbonic acid)

3. H2CO3 dissociates to form HCO3- (bicarbonate ion) and H+ (hydrogen ion)

4. The H+ is pumped out of the parietal cell via a proton pump into the stomach lumen. HCO3- ion is pumped into the interstitial fluid.

5. Cl- enters the parietal cell and is then sent into the stomach lumen.

6. In the stomach lumen, H+ + Cl- —> HCl

Note: HCO3- (bicarbonate ion) in the interstitial fluid diffuse into the bloodstream. When gastric acid (HCl) is being secreted there is a large influx of bicarbonate ions being released into the bloodstream. These ions raise the pH in the bloodstream. This is called the alkaline tide, the temporary increase in blood pH after eating a meal.

Trace a Piece of Pizza Through the Stomach

1. Oral Cavity

2. Pharynx

3. Esophagus

4. Stomach

5. Duodenum

6. Jejunum

7. Ileum

8. Ileocecal valve

9. Cecum

10. Ascending colon

11. Right colic flexure (hepatic flexure)

12. Transverse colon

13. Left colic flexure (splenic flexure)

14. Descending colon

15. Sigmoid colon

16. Rectum

17. Anus

18. Toilet