Chapter 23: Digestive System

Question 1

Function of the digestive system

Answer 1

1. Ingestion
2. Propulsion
3. Mechanical and Chemical digestion
4. absorption
5. Excretion/defecation

Question 2

Peristalsis

Answer 2

Alternative waves of contraction and relaxation that move food through the gastrointestinal tract

Question 3

4 historical layers of the intestinal tract

Answer 3

1. Mucosa
2. Submucosa
3. Muscularis externa
4. Serosa

Question 4

2 layers of the muscularis externa

Answer 4

1. Circular inner layer

2. longitudinal layer

Question 5

2 enteric nerve plexus - provide intrinsic innervations to the digestive tract

Answer 5

1. Submucosal plexus

2. Myenteric plexus

Question 6

Smooth muscles from skeletal muscles

Answer 6

1. no striations (no sarcomeres)
2. Intermediate fibers and dense bodies to anchor sliding filaments
3. caveolae of the sarcolemma
4. Slower rate of contraction
5. Gap junctions generally present to spread depolarization between fibers
6. smooth muscle fibers contract as a single functional unit - a syncytium

Question 7

T or F: the esophagus joins the stomach beneath the diaphragm

Answer 7

True

- has cardiac sphincter mechanism to prevent reflex of stomach acid in the the esophagus

Question 8

3 muscle layers of the stomach

Answer 8

1. Oblique
2. Circular
3. Longitudinal

Question 9

3 main cell types in the stomach

Answer 9

1. Mucous cell
2. Parietal cell
3. Chief cell

Question 10

Mucous cell secretion

Answer 10

Mucus

Question 11

Parietal cell secretion

Answer 11

HCL acid

Question 12

Chief cell secretion

Answer 12

Pepsinogen

Question 13

3 divisions of the small intesine

Answer 13

1. Duodenum
2. Jejunum
3. Ileum

Question 14

T or F: Duodenum is the entry point of the hepatopancreatic ampulla

Answer 14

True

- Joins the bile duct from the liver and the brain pancreatic duct that carries digestive enzymes and bicarbonate

Question 15

Role of lacteal in the Villi

Answer 15

Functions in far absorption from intestinal tract

• Absorbed fact is transported via lymphatic to the thoracic duct bypassing the liver on way into the vascular space
• Micro villi form the bush border of each lacteal and greatly increase surface area for absorption and provide surface enzymes

Question 16

Features of the large bowel

Answer 16

1. Tenae coli
2. Haustra
3. Epoplocic appendages

Question 17

Division of the large intestine

Answer 17

1. Cecum
2. Vermiform appendix
3. Colon (ascending, transverse, descending and sigmoid)
4. Rectum
5. Anal canal

Question 18

Portal triad (3)

Answer 18

1. Bile Duct
2. Portal arteriole
3. portal vein

Question 19

T or F: Gall bladder stores bile produced by hepatocytes and contracts to release it in response to the hormone cholecystokinin

Answer 19

True

- CCK is secreted in response ti a fatty meal and bile salts emulsify lipids for chemical digestion

Question 20

Pancreatic acinar cells

Answer 20

source of multiple digestive enzymes that provide pancreatic exocrine function