Section 1 & 2

Question 1

Name the parts of the digestive tract in order.

Answer 1

Mouth, oral cavity, pharynx, esophagus, stomach, small intestine, large intestine and anus

Question 2

What is the alimentary canal?

Answer 2

The digestive tract

Question 3

What two groups are the organs in the digestive system divided into?

Answer 3

The digestive tract and the accessory digestive organs

Question 4

What are the accessory digestive organs?

Answer 4

Tongue, teeth, salivary glans, liver, biliary ducts and gallbladder, and pancreas.

Question 5

Describe the functions of the digestive tract.

Answer 5

1. Digestion: mastication (chewing) crushes the food into smaller pieces to facilitate chemical processing by enzymes into small molecules.
2. Absorption: Digestion is completed in the small intestine and here most nutrients are absorbed. In the large intestine, water, vitamins, etc. are absorbed.
3. Secretion: In the presence of food, cells of the stomach’s mucosal wall release gastric acid to perform chemical digestion.
4. Motility: When food is swallowed, muscles in the esophageal wall contract and relax to push food through the esophagus down to the stomach.
5. Elimination of waste: Leftover materials, which are not absorbed or utilized by the body are eliminated by the process of defecation (shitting)

Question 6

What is the mucosa of the digestive tract, and the parts?

Answer 6

The innermost layer of the digestive tract wall. Composed of three main elements: surface epithelium, lamina propria, and muscularis mucosa.

Question 7

Describe the function of surface epithelium of the mucosa of the digestive tract wall.

Answer 7

The type of epithelial layer reflects the expected function of the organ. Examples of functions include secretion, absorption, and protection.

Question 8

What is lamina propria?

Answer 8

A layer of loose connective tissue under the surface epithelium of the mucosa (e.g in the digestive tract wall).

Question 9

What is the muscularis mucosa?

Answer 9

• the layer of the mucosa of the digestive tract wall
• composed of smooth muscle fibers
• under the lamina propria.

Question 10

What is the submucosa of the digestive tract wall?

Answer 10

• the layer below the mucosa
• composed of dense irregular connective tissue
• contains blood vessels, lymphatics, glands and nerve plexuses

Question 11

What is the muscularis externa of the digestive tract wall?

Answer 11

• composed of circular and longitudinal layers of smooth muscle with nerve plexuses in between the layers
• the plexuses are responsible for muscular contraction to propel food through the digestive tract

Question 12

What is serosa/adventitia of the digestive tract wall?

Answer 12

• the outermost layer of the digestive tract is either a serosa or an adventitia

Serosa:
- when the layer is serous membrane (a single layer of thin, flat cells that form a membranous sheet and secrete lubricating fluid)

Adventitia:
- when the outer layer is composed of loose connective tissue

Question 13

Summarize the layers of the digestive tract wall, innermost to outermost.

Answer 13

inner

1. Mucosa: composed of surface epithelium, lamina propria, and muscularis mucosa
2. Submucosa: a layer of dense irregular connective tissue with blood vessels, nerves, lymphatics, glands, etc.
3. Muscularis externa: circular and longitudinal layers of smooth muscle that account for peristalsis and segmentation
4. Serosa OR adventitia: layer that is either serous in nature, or composed of loose connective tissue

outer

Question 14

What does the oral cavity consist of?

Answer 14

• The vestibule (the space between the cheeks and lips and the gums and teeth)
• The oral cavity proper (the other areas of the mouth)

Question 15

What is the palate?

Answer 15

The palate makes up the superior border of the oral cavity
- divided into the hard palate (bone) and soft palate (muscle)
- the posterior extension of the soft palate is called the uvula

Question 16

What are the two types of teeth humans have?

Answer 16

Deciduous and permanent

Question 17

What are deciduous teeth?

Answer 17

“Baby teeth”
Consists of (total 20 teeth in the whole mouth):
- 2 incisors
- 1 canine (cuspid)
- 2 molars in each quadrant of the jaw

Question 18

What are permanent teeth?

Answer 18

Consists of (32 teeth total in the whole mouth):
- 2 incisors
- 1 canine (cuspid)
- 2 premolars (bicuspids)
- 3 molars in each quadrant of the jaw

interesting* the two pairs of third molars are known as our “wisdom teeth”!

Question 19

Which muscles control the shape of the tongue itself?

a) intrinsic
b) extrinsic

Answer 19

a) intrinsic

Question 20

Which muscles move the tongue during chewing and speech?

a) intrinsic
b) extrinsic

Answer 20

b) extrinsic

Question 21

What are the different types of muscles in the tongue, and what do they both do?

Answer 21

• Intrinsic muscles: control the shape of the tongue itself
• Extrinsic muscles: move the tongue during chewing and speech

Question 22

What is the frenulum?

Answer 22

On the interior surface of the tongue, and it anchors the tongue to the floor of the mouth.

Question 23

What are the papillae of the tongue, where are they, and what is their function?

Answer 23

• on both the superior and lateral surfaces of the tongue
• they are projections or bumps
• there are four types of papillae, some of which contain taste buds, allowing the humans the sense of gustation

Question 24

What are the three major salivary glands, and what do they secrete?

Answer 24

1. Parotid:
   - secretes serous (watery) fluid
   - located anterior and inferior to the external ear opening
2. Submandibular:
   - secretes serous and mucous (viscous) fluid
   - inferior to the mandible
3. Sublingual:
   - secretes mucus
   - inferior to the tongue

Question 25

What are tonsils and what are the three tonsils?

Answer 25

Tonsils are collections of lymphoid tissue found in areas of the pharynx. They play a role in the immune system.

The three tonsils are:
1. Palatine tonsils
2. Pharyngeal tonsil
3. Lingual tonsils