T2. DIGESTIVE PROCESSES IN MOUTH, PHARINX AND ESOPHAGUS

Question 1

What type of epithelium covers the mouth?

Answer 1

Stratified squamous epithelium

Question 2

What are the functions of the mouth?

Answer 2

Ingestion, mastication, chemical digestion, and swallowing

Question 3

What triggers the involuntary chewing reflex?

Answer 3

Stimulation of oral receptors by food

Question 4

What muscles elevate the teeth to crush food?

Answer 4

Muscles involved in the chewing reflex

Question 5

What does mastication accomplish?

Answer 5

Breaks food into smaller pieces for easier swallowing and enzyme action

Question 6

What is the role of the tongue in mastication?

Answer 6

Manipulates food for mechanical digestion

Question 7

What are the functions of saliva?

Answer 7

Moistens mouth, starts starch digestion, cleans teeth, inhibits bacterial growth, stimulates taste, moistens/binds food into bolus

Question 8

What is the pH of saliva?

Answer 8

Between 6.8 and 7.0

Question 9

What is the water content of saliva?

Answer 9

97.0% to 99.5% water

Question 10

What digestive enzyme in saliva starts starch digestion?

Answer 10

Salivary amylase

Question 11

What enzyme in saliva is activated by stomach acid to digest fat?

Answer 11

Lingual lipase

Question 12

What is the role of mucus in saliva?

Answer 12

Lubricates and binds food into a bolus

Question 13

What is the function of lysozyme in saliva?

Answer 13

Kills bacteria

Question 14

What is the function of IgA in saliva?

Answer 14

Antibody that inhibits bacterial growth

Question 15

What electrolytes are found in saliva?

Answer 15

Na⁺, K⁺, Cl⁻, phosphate, and bicarbonate

Question 16

What are intrinsic salivary glands?

Answer 16

Small glands dispersed in oral tissues

Question 17

What are the types of intrinsic salivary glands?

Answer 17

Lingual (tongue), labial (lips), and buccal (cheeks)

Question 18

What are extrinsic salivary glands?

Answer 18

Larger glands connected to the oral cavity by ducts

Question 19

What are the three pairs of extrinsic salivary glands?

Answer 19

Parotid, submandibular, and sublingual

Question 20

Where is the parotid gland located?

Answer 20

Beneath the skin anterior to the earlobe

Question 21

Where is the submandibular gland located?

Answer 21

Halfway along the body of the mandible

Question 22

Where are the sublingual glands located?

Answer 22

In the floor of the mouth with multiple ducts

Question 23

What is the structure of salivary glands at the microscopic level?

Answer 23

Branched ducts ending in acini

Question 24

What do mucus acini secrete?

Answer 24

Mucus

Question 25

What do serous acini secrete?

Answer 25

Thin fluid rich in amylase and electrolytes

Question 26

What are mixed acini?

Answer 26

Acini with both mucous and serous cells

Question 27

How is salivation controlled?

Answer 27

By salivary nuclei responding to food signals and autonomic fibers

Question 28

What does parasympathetic stimulation produce in salivation?

Answer 28

Abundant, thin, enzyme-rich saliva

Question 29

What does sympathetic stimulation produce in salivation?

Answer 29

Less, thicker saliva with more mucus

Question 30

What do acinar cells add to saliva?

Answer 30

Amylase, mucin, and lysozyme

Question 31

How much saliva do extrinsic salivary glands secrete per day?

Answer 31

About 1 to 1.5 liters

Question 32

What is the pharynx?

Answer 32

A muscular funnel connecting oral cavity to esophagus and air to larynx

Question 33

What is the function of the pharynx?

Answer 33

Transports food and air

Question 34

What are pharyngeal constrictors?

Answer 34

Superior, middle, and inferior circular muscles that force food downward

Question 35

What is the esophagus?

Answer 35

A straight muscular tube 25–30 cm long from pharynx to stomach

Question 36

Where does the esophagus pass through the diaphragm?

Answer 36

Esophageal hiatus

Question 37

What structures are found in the esophagus?

Answer 37

Sphincters and esophageal glands in submucosa

Question 38

What happens to the esophagus when empty?

Answer 38

Folds into longitudinal ridges

Question 39

What is deglutition?

Answer 39

Swallowing—a complex action using over 22 muscles

Question 40

Which muscles control the upper part of swallowing?

Answer 40

Skeletal muscles innervated by somatic motor neurons

Question 41

Which muscles control the lower esophagus?

Answer 41

Smooth muscle controlled by the autonomic nervous system

Question 42

What are the two phases of swallowing?

Answer 42

Buccal phase (voluntary) and pharyngoesophageal phase (involuntary)

Question 43

What occurs in the buccal phase?

Answer 43

Tongue collects food into a bolus and pushes it to oropharynx

Question 44

How is the epiglottis involved in swallowing?

Answer 44

Tips posteriorly to allow bolus to slide around into laryngopharynx

Question 45

What triggers the pharyngoesophageal phase?

Answer 45

Stimulation of tactile receptors in the laryngopharynx

Question 46

What prevents food from entering nasal cavity and larynx during swallowing?

Answer 46

Involuntary actions of the pharyngoesophageal phase

Question 47

What moves the bolus down through the pharynx?

Answer 47

Sequential constriction of superior, middle, and inferior pharyngeal constrictors

Question 48

What triggers peristalsis in the esophagus?

Answer 48

Bolus stretching the esophagus

Question 49

What happens at the lower end of the esophagus during swallowing?

Answer 49

The lower esophageal sphincter relaxes to let food into the stomach