Chapter 18-1

Question 1

Six (6) major functions of the Digestive System

Answer 1

1. Ingestion
2. Secretion
3. Digestion: Mechanical and Chemical
4. Mixing and Propulsion
5. Absorption: from the lumen into the bloodstream
6. Defecation

Question 2

Describe the alimentary canal and accessory organs of the digestive system. Identify specific organs that are examples of each category

Answer 2

Alimentary Canal: “digestive tract” from mouth to anus. Digests and absorbs nutrients.

Canal Organs: Mouth, Pharynx, Esophagus, Stomachm, Small Intestine, Rectum & Anus

Accessory Organs: Pancreas, Liver and Gallbladder

Question 3

Define: Mastication, Bolus & Deglutition

Answer 3

1.Mastication: Chewing Food
2.Bolus: Food that is masticated/ coated with Saliva
3.Deglutition: Act of swallowing a bolus

Question 4

Describe the two (2) types of digestion that typically occur inside of the alimentary canal.

Answer 4

1. Mechanical Digestion: physical process of breaking down food into smaller pieces
2. Chemical Digestion: process of breaking down food into smaller molecules using enzymes

Question 5

Describe the functions of secretion and absorption and how it relates to the digestive system

Answer 5

Secretion and absorption is part of both mechanical and chemical digestion

Question 6

histology of the alimentary canal:
The tissue layer that is most superficial and helps anchor digestive organs to
surrounding structures in the abdominal cavity:

Answer 6

Serosa

Question 6

histology of the alimentary canal:
The tissue layer where secretion and absorption occurs

Answer 6

Mucosa

Question 6

histology of the alimentary canal:
The tissue layer that comes in direct contact with food/fluids in the alimentary canal

Answer 6

Mucosa

Question 6

Identify the two (2) functions of the peritoneum

Answer 6

1. Anchors the abdominal organs
2. Protects the abdominal organs

Question 7

histology of the alimentary canal:
The tissue layer that anchors the mucosa to the muscularis:

Answer 7

Submucosa

Question 7

histology of the alimentary canal:
The tissue layer that consists of either smooth or skeletal muscle

Answer 7

Muscularis

Question 7

Components of the peritoneum:
Greater omentum

Answer 7

Largest fold, associated with beer bellies protects anterior abdomen

Question 8

Components of the peritoneum:
Lesser omentum

Answer 8

Anchors stomach and Duodenum to liver

Question 9

Components of the peritoneum:
Falciform ligament

Answer 9

Anchors liver to diaphragm and anterior abdominal wall

Question 10

Components of the peritoneum:
Mesentery

Answer 10

Anchors jejunum and illeum to posterior abdominal wall

Question 11

Components of the peritoneum:
Mesocolon

Answer 11

Anchors large intestine to the posterior abdominal wall

Question 12

Explain the function of the uvula in the oral cavity

Answer 12

Prevents substance in the oral cavity from passing top to the nasal cavity

Question 13

Regarding teeth:
What type of teeth are found most posterior in the mouth?

Answer 13

Molars

Question 14

Regarding teeth:
The total number of adult teeth?

Answer 14

32

Question 15

Regarding teeth:
Usually the sharpest teeth in the mouth

Answer 15

Canine

Question 16

Regarding teeth:
What type of teeth are wisdom teeth?

Answer 16

3rd Molars

Question 17

Regarding teeth:
what type of teeth are found most anterior in the mouth

Answer 17

Incisors

Question 18

Regarding teeth:
Part of tooth that is exposed to the surface and contains enamel

Answer 18

Crown

Question 19

Regarding teeth:
Part of teeth that sits at the gum line

Answer 19

Neck

Question 20

Regarding teeth:
Part of the tooth that sits inside the tooth socket

Answer 20

Root

Question 21

What function does the periodontal ligament serve?

Answer 21

Anchors the tooth inside the alveolar process (tooth socket) and absorbs impact

Question 22

Identify and explain the three (3) functions of saliva

Answer 22

1. Lubrication of food (easier to swallow)
2. Digestion: via Salivary amylase and Lingual lipase
3. Immunity: IgA antibodies

Question 23

What is the primary function of the esophagus?

Answer 23

Esophagus: Propulsion

Question 24

Explain how the composition of muscle and how it changes as you progress from superior to
inferior through the esophagus.

Answer 24

1. Superior: Muscularis = skeletal muscle
2. Middle: Muscialris mixture of skeletal and smooth muscle
3. Inferior: Smooth muscle

Question 25

Describe the purpose of the following:

1. Upper esophageal sphincter
2. Lower esophageal sphincter

Answer 25

1. Upper esophageal sphincter— Separates upper esophagus from the pharynx
2. Lower esophageal sphincter— Seperates lower esophagus from the cardia (stomach)

Question 26

Which sphincter is associated with gastroesophageal reflux (heartburn)?

Answer 26

“heart burn” stems from the inferior sphincter = Lower esophageal sphincter

Question 27

Identify and briefly describe the four (4) primary functions of the stomach

Answer 27

Stomach Regions
Cardia: connects the stomach to the lower esophagus
Body: main portion of the stomach
Fundus: upper extensionn
Pylorus: connects the stomach to the duodenum

Functions:
1. Reservoir of food
2. Production of chyme (liquefied food)
3. Chemical digestion
4. Controlled release of chyme into the duodenum

Question 28

What is the significance of rugae in the stomach?

Answer 28

Folds in the mucosal lining of the stomach that allow expansion

Question 29

Explain the importance of the following types of cells located in the stomach:

a. Mucous neck cells
b. Parietal cells
c. Chief cells
d. G cells

Answer 29

a. Mucous neck cells— gastritis pits, secrete mucous on the lining of the stomach
b. Parietal cells— secrete HCl and Intrinsic factor
c. Chief cells— secrete Pepsinogen which is activated pinto pepsin
d. G cells— only endocrine cell, secretes gastrin inro bloodstream