Digestive System Overview & Anatomy of the Mouth, Pharynx and Esophagus

Question 1

Name the 2 main divisions of the digestive system organs.

Answer 1

Alimentary Canal

Acessory Digestive Organs

Question 2

Name the 7 parts of the gastrointestinal tract.

Answer 2

1. mouth
2. pharynx
3. esophagus
4. stomach
5. small intestine
6. large intestine
7. anus

Question 3

Name the 6 digestive system accessory organs.

Answer 3

1. teeth
2. tongue
3. gallbladder
4. salivary glands
5. liver
6. pancreas

Question 4

review diagrams etc.

Answer 4

look at the diagrams etc

Question 5

What structures respectively form these parts of the mouth?

a. opening
b. floor
c. walls
d. roof

Answer 5

a. opening = lips
b. floor = tongue
c. walls = cheeks
d. roof = hard / soft palates

Question 6

List the 2 bones, and the membrane to which the tongue is attached.

Answer 6

The tongue is attached to the HYOID BONE and the MANDIBLE. The membranous LINGUAL FRENULUM.

Question 7

How many teeth are there in the adult human and what do they do?

Answer 7

32 teeth. Together they work to
tear
crush,
grind food to mechanically digest food

Question 8

What are the 4 types of teeth, how many of each type are there, and what does each type do?

Answer 8

(in each of the four quadrants):
2 incisors - for biting
1 canine - for tearing
2 pre-molars - for grinding
3 molars - for crushing

Question 9

What is the specific function of the salivary gland in the process of digestion?

Answer 9

Food is mixed and moistened with saliva (from the salivary glands) containing enzymes that begin the process of chemical digestion by breaking down starches.

Question 10

Where are the taste buds located?

Answer 10

Taste buds are found primarily on the tongue, but also on the surface of the mouth, and the wall of the pharnyx.

Question 11

Describe the function of the tongue in the digestive process.

Answer 11

The tongue grips the food, constantly repositions it between the teeth, and forms it into a compact mass which is pushed back to the pharynx to begin the process of swallowing.

Question 12

What is a bolus?

Answer 12

A bolus is a compact mass of food formed by the combination fo chewing by the teeth and repositioning by the tongue.

Question 13

List the 3 parts of the pharynx.

Answer 13

the nasopharynx
the oropharynx
the laryngopharynx

Question 14

Through which sections of the pharynx does air travel?

Through which sections of the pharynx does food travel?

Answer 14

Air enters the nose, continues through the nasopharynx, oropharynx, and the laryngopharnyx. Air then enters the trachea on its way to the lungs.

Food and liquids enter the mouth, continue through the oropharynx and the laryngopharnx but then continue into the esophagus.

Question 15

What prevents food from entering the lungs? And why is this necessary?

Answer 15

Food is prevented from entering the larynx by the epiglottis, a flap of elastic cartilage which covers the lzynx when swallowing food or liquid.

Question 16

What are the two types of skeletal muscles in the pharynx.

What do these two muscular layers do to assist with food passage?

Answer 16

• circumferential outer layer
• inner longitudinal layer

These muscles contract alternatively squeezing food into the esophagus.

Question 17

List and describe the tissue layers of the esophagus.

Answer 17

There are 4 layers of tissue in the esophagus:

1. mucosa - innermost layer that secretes mucus into the interior of the GI tract.
2. Submucosa - contains blood and lymph vessels, lymph nodes, nerves and mucous glands
3. Muscularis Externa - made up of 2 layers of muscle: the outer longitudinal fibers and inner circumferential fibers
4. Serosa - the outermost layer made up of cells that make serous fluid

Question 18

Explain peristalsis.

Answer 18

Peristalsis is the squeezing of food through the GI tract by the alternating contraction of the sets of longitudinal and circumferential muscles.

Question 19

What are the 3 main divisions of the tooth?

Answer 19

• the crown
• the neck
• the root

Question 20

What are the 3 types of papillae on the tongue? Which two contain taste buds?

Answer 20

3 types of papillae which help to grip food on the tongue:

• circumvallate
• fungiform
• filiform

The Circumvallate and Fungiform Papillae both contain taste buds.