Quiz 9

Question 1

What is the digestive system?

Answer 1

aka alimentary canal; stomach as organ, villi as basic unit; about 30 feet long with two openings (mouth/stomadeum, anus/proctadeum); includes mouth, esophagus, stomach, small intestine, and large intestine

Gut Wall: made of serosa (outer; 100% epithelium). muscle (visceral, ANS, peristalsis), mucus (sticky), sub-mucus (innermost; wavy)

Question 2

What is the mouth?

Answer 2

aka stomadeum, buccal/oral cavity; 5% of total digestion, breaks down carbohydrates into saccharides

MECHANICAL: teeth for chewing; tongue, glossal, lingual for mixing food bits and saliva

CHEMICAL: salivary glands that produce enzymes

1. Parotid: squirts; profuces ptaylin (monosaccharide)
2. Tongue
3. Sub-lingual: under tongue; produces lipase (lipid)
4. Sub-mandibular: under jaw; produces amylase (dominant; polysaccharides; breaks down into glucose, level should be under 100 parts per million; stored as glycogen in liver)
5. Pharynx: back of mouth; beginning of esophagus

Question 3

What is the esophagus?

1, 2

Answer 3

connects pharynx to stomach; 0% digestion; about one foot long, but tri-innervated (CNS, control - ANS/CNS, some control - ANS, no control)

1. Esophagus
2. Cardiac Sphincter: located at the end of the esophagus, right above the stomach; regulates amount of food that enters stomach

Question 4

What is the stomach?

3, 4, 5, 6, 7

Answer 4

use mainly as food resevoir; 100% visceral muscle; about one gallon in volume; 5% of total digestion, breaks down proteins into proteins

Deamination: proper digestion of proteins in the stomach; produce creatinine and urea; dairy is dissolved by renin; meat is dissolved by pepsin; fats are dissolved by lactase

Omentum: lesser/superioir, greater/inferior; keep shape of stomach

3. Cardid
4. Rugae: muscular folds of the stomach; lined with cells; pit under; parietal epithelial (produce gastrin) cells; chief cells (produce hypochloric acid of a pH 2-3)
5. Fundus
6. Pylorus: has villi
7. Pyloric Sphincter: regulates the amount of food that enters the small intestine

Question 5

What is the small intestine?

1, 2, 3

Answer 5

90% of total digestion; cotains all enzymes and decreasing amount of villi; divided into duodenum (most active), jejunum (somewhat active), and ileum (least active)

1. Ileocecal Sphincter: regulates amount of food that enters the large intestine
2. Appendix: non-functional in humans
3. Cecum: indicates beginning of large intestine

Question 6

What is the large intestine?

4, 5, 6, 7, 8, 9

Answer 6

aka colon; 0% of total digestion; reabsorbs salt and water

Formation of Feces: probiotic bacteria mis fibers and undigested food together to make a solid mass

4. Ascending Colon
5. Transverse Colon
6. Descending Colon
7. Sigmoid: s-shaped structure near end of colon
8. Rectum: pocket before the anal sphincter
9. Anal Sphincter: regulated smount of waste that leaves the body

Question 7

What is symbiosis? What are the three types?

Answer 7

two different organisms that live together

1. Commensalism: one benefits; the other is unharmed
2. Mutual: both benefit
3. Parasitic: one benefits; the other is harmed

Question 8

Define mastication, deglutination, distension, bolus, and chyme.

Answer 8

Mastication: to chew

Deglutination: to swallow

Distension: to expand

Bolus: semi-digested food within the mouth

Chyme: semi-digested food within the stomach

Question 9

Define ulcer, sphincter, appendicitis, and lactose-intolerant.

Answer 9

Ulcer: hole that has been eaten away by acid or gird-acid reflex

Spincter: strong muscular valve of ANS innervation

Appedicitis: inflammation of the appendix that causes sharp pains and fevers; may lead to death if ruptured

Lactose-Intolerant: lack of lactase enzyme