Digestive System-1

Question 1

What are the 6 main functions of the digestive system

Answer 1

1. Take in food, 2. break food into molecules, 3. absorb molecules into the bloodstream, 4. rid body of indigestible remains, 5. produce nutrients, 6. produce neurotransmitters

Question 2

What is the purpose of the alimentary canal? what are the associated organs?

Answer 2

the purpose is to digest and absorb food through the mucosal lining into the blood.

the associated organs are the mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus

Question 3

what is the purpose of the accessory digestive organs? what are the associated organs?

Answer 3

the purpose is mechanical and chemical digestion of food

the associated organs are the teeth, the tongue, the gallbladder, and the digestive glands(saliva, liver, pancreas)

Question 4

what are the 6 major digestive processes?

Answer 4

ingestion, mechanical breakdown, propulsion, digestion, absorption, compaction/digestion

Question 5

What is the difference between peristalsis & segmentation?

Answer 5

Peristalsis involves adjacent segments of alimentary tract organs whereas segmentation involves nonadjacent segments of alimentary tract organs.

Peristalsis only has forward movement whereas segmentation has forward and backward movement.

Question 6

What is the difference between visceral and parietal peritoneum?

Answer 6

Visceral peritoneum is the membrane that lines the outside of digestive organs

Parietal peritoneum is the membrane that lines the entire body wall

Question 7

What is the peritoneal cavity? what does it do?

Answer 7

A fluid filled space between two peritoneum’s.

It lubricates mobile organs.

Question 8

What is a mesentery? what is it’s purpose?

Answer 8

A double layer of peritoneum fused together

It provides support for the organs(holds them in place), provides support for the vessels and nerves that supply the organs, and it stores fat

Question 9

What is the difference between intraperitoneal and retroperitoneal rogans?

Answer 9

Intraperitoneal organs are located within the peritoneum

Retroperitoneal organs are located outside the peritoneum

Question 10

What are 4 defining characteristics of the alimentary canal?

Answer 10

it extends from the mouth to the anus

most of the length is from the small intestine

the wall consists of 4 tissue layers

food travelling down the canal is broken down chemically from juices that are secreted by the digestive organs

Question 11

what are the 4 basic tissue layers of all digestive organs?

Answer 11

Mucosa, Submucosa, Muscularis externa, Serosa

Question 12

what are the 3 functions of the mucosa?

Answer 12

Secretion of mucus, digestive enzymes, hormones
Absorption of the end products of digestion
Protection from infectious disease

Question 13

What are the 3 sublayers of mucosa? what is the main function of each?

Answer 13

Epithelium-secrete enzymes and hormones
Lamina Propria-absorption/protection
Muscularis mucosae-movement

Question 14

What are 2 distinguishing features of the submucosa?

Answer 14

Allows stomach to regain shape after a big meal

Has a submucosal nerve plexus

Question 15

What are 2 distinguishing features of the muscularis externa?

Answer 15

Where segmentation/peristalsis occurs

Has a myenteric nerve plexus

Question 16

What are the 4 major arteries that give blood supply to the digestive system?
Where do they send blood to?

Answer 16

Hepatic artery-sends blood to the liver
Celiac artery-sends blood to the stomach and spleen
Superior & Inferior mesenteric artery-sends blood to the small & large intestine

Question 17

What is the unique name for the nervous system of the digestive tract? What is it’s main function?

Answer 17

Enteric nervous system or “gut brain”

It controls motility

Question 18

What is the main function of the submucosal and myenteric nerve plexus?

Answer 18

Submucosal nerve plexus regulates the glands and smooth muscle in the mucosa

Myenteric nerve plexus controls GI tract motility

Question 19

What is the difference between short and long reflexes in the gut brain?

Answer 19

Short reflexes respond to stimuli inside the GI tract and control peristalsis/segmentation

Long reflexes respond to stimuli both inside and outside the GI tract and interact the CNS(ex. smelling food makes you hungry)

Question 20

What are the 3 key concepts that regulate digestive activity?

Answer 20

• Digestive activity is provoked by mechanical and chemical stimuli(ex. stretch, blood pH)
• The 2 effectors of digestive activity are the smooth muscles and the digestive glands(muscles move lumen contents, glands release digestive juices)

The 2 controllers of digestive activity are the nervous system and hormones(short and long reflexes of nervous system, ghrelin and leptin hormones of digestive system)