22.1: Overview of the Digestive System

Question 1

Define the digestive system.

Answer 1

The set of organs that breaks down food items into nutrients that can be delivered by bloodstream to cells in the body.

Question 2

The organs of the digestive system are located from the ______ to the ___________.

Answer 2

head, abdominopelvic cavity

Question 3

What 2 types of organs make up the digestive system?

Answer 3

The organs of the alimentary canal (GI/digestive tract) and the accessory organs.

Question 4

The alimentary canal is a ________________ through which food moves.

Answer 4

Continuous passage

Question 5

What does the alimentary canal consist of (parts involved)?

Answer 5

The oral cavity (mouth), pharynx, esophagus, stomach, small intestine, and large intestine.

Question 6

Are the accessory organs part of the alimentary canal?

Answer 6

No, but they aide in digestion in some way.

Question 7

Name the accessory organs (located around the alimentary canal).

Answer 7

Teeth, tongue, salivary glands, liver, gallbladder, and pancreas.

Question 8

Does food usually come into contact with the accessory organs? If not, are there exceptions?

Answer 8

Food does NOT usually contact the accessory organs; teeth and tongue are the exceptions.

Question 9

Where do most digestive organs reside (what cavity)?

Answer 9

The abdominopelvic cavity.

Question 10

Digestive organs of the abdominopelvic cavity share a common set of _____ membranes, ______ vessels, and nerves.

Answer 10

Serous, blood

Question 11

How are tissue layers of the alimentary cavity arranged?

Answer 11

Inner mucosa, middle loose connective tissue and smooth muscle, and outer dense connective tissue.

Question 12

What is the largest serous membrane in the body?

Answer 12

The peritoneal membrane (also called the peritoneum).

Question 13

How many layers make up the peritoneal membrane?

Answer 13

2

Question 14

What is the outer layer of the peritoneum called? What does it line?

Answer 14

The parietal peritoneum; it lines the inner surface of the body wall.

Question 15

What is the folded over part of the parietal peritoneum called (the inner layer of the peritoneum)?

Answer 15

The visceral peritoneum (also called serosa). It forms the outer tissue layer of organs touched by the parietal peritoneum.

Question 16

What is located between the 2 layers of the peritoneum? What does it contain?

Answer 16

The peritoneal cavity; serous fluid that lubricates the organs as they slide against each other.

Question 17

What is peritonitis?

Answer 17

Inflammation of the peritoneum.

Question 18

What causes peritonitis?

Answer 18

Peritonitis results when substances such as blood or the contents of an abdominal organ leak into the peritoneal cavity. This is typically due to abdominal trauma and often involves a bacterial infection.

Question 19

What is rebound tenderness?

Answer 19

Patients feel little pain when a hand is placed on their abdomen, but significant pain when the hand is removed. Caused by inflamed peritoneal membranes snapping back into place once the hand leaves.

Question 20

How is peritonitis treated?

Answer 20

Surgery and antibiotics.

Question 21

Define intraperitoneal organs.

Answer 21

Organs located entirely within the peritoneal cavity.

Question 22

Define retroperitoneal organs.

Answer 22

Organs completely or partly outside the peritoneal cavity.

Question 23

Define mesenteries.

Answer 23

Double folds of visceral peritoneum located around certain abdominal organs (such as the small and large intestines).

Question 24

What do the mesenteries do?

Answer 24

They support and bind organs together and keep the small intestine in a particular shape that fits in the abdominopelvic cavity. They also house blood vessels, nerves, and lymphatic vessels and anchor them in place.

Question 25

What is the mesocolon?

Answer 25

The mesentery attached to much of the large intestine.

Question 26

What are the 2 prominent mesenteries?

Answer 26

The greater omentum (“apron”) and the lesser omentum.

Question 27

How many layers of folded visceral peritoneum make up the greater omentum?

Answer 27

4 layers of folded visceral peritoneum.

Question 28

What is the first visible structure when the abdominal cavity is opened?

Answer 28

The greater omentum.

Question 29

Which omentum is smaller?

Answer 29

The lesser omentum.

Question 30

The organs of the digestive system are ________ supplied with blood vessels and nerves.

Answer 30

Extensively

Question 31

Define splanchnic circulation.

Answer 31

The collection of blood vessels that supplies and drains the digestive organs in the abdominopelvic cavity.

Question 33

What do branches of the celiac trunk, superior mesenteric artery, and inferior mesenteric artery have in common?

Answer 33

They are branches from the abdominal aorta that supply the digestive organs with blood.

Question 34

Where do digestive organ veins drain to?

Answer 34

The hepatic portal vein.

Question 35

What are the two branches of the autonomic nerbous system?

Answer 35

The sympathetic nervous system and the parasympathetic nervous system.

Question 36

Define a plexus.

Answer 36

A cluster of nerves.

Question 37

What are the three main nerve clusters that serve the abdominal digestive organs?

Answer 37

The celiac plexus, the superior mesenteric plexus, and the inferior mesenteric plexus. Note: these have the same names as the arteries that supply the digestive organs! :)

Question 38

Define the enteric nervous system.

Answer 38

A self-contained branch of the autonomic nervous system that extends from the esophagus to the anus. It regulates secretion and motility of the digestive organs.

Question 39

What are the 4 main tissue layers of the alimentary canal?

Answer 39

Mucosa, submucosa, muscularis externa, and either the serosa or the adventitia. These layers surround a hollow space called the lumen.

Question 40

Name the 3 components of the mucosa.

Answer 40

Epithelium, lamina propria (LCT), and 2 layers of SM called the muscularis mucosae.

Question 41

What does mucus do in relation to the epithelium?

Answer 41

Coats the epithelium and protects it and its underlying organs from ingested food and chemical signals secreted by the digestive organs.

Question 42

Regenerative epithelial cells have a high rate of _________.

Answer 42

Mitosis. This means they are able to be quickly replaced.

Question 43

What is the submucosa made up of (tissue-wise)?

Answer 43

Dense irregular connective tissue.

Question 44

What regulates the motility of the muscularis externa?

Answer 44

The myenteric plexus.

Question 45

Serosa is the outer connective tissue layer for organs ______ the peritoneal cavity, while adventitia is the layer for organs _______ the peritoneal cavity.

Answer 45

Inside, outside. Both structures support digestive organs and anchor them to surrounding structures.

Question 46

What is motility?

Answer 46

The movement of a cell or tissue.

Question 47

What do swallowing, churning, peristalsis, and defecation have in common?

Answer 47

They are forms of motility of the digestive system.

Question 48

Sympathetic activity ______ digestive processes, while parasympathetic activity ______ them.

Answer 48

Inhibits, stimulates

Question 49

What is motility regulated by (in the digestive system)?

Answer 49

The ENS

Question 50

Functions stimulated by the ENS are called ______ reflexes, while functions stimulated by the ANS are called ______ reflexes.

Answer 50

Short, long

Question 51

The endocrine system regulates digestive processes by secreting what?

Answer 51

Hormones