2.1 Salivation and Swallowing

Question 1

What is saliva? What does in contain?

Answer 1

A hypotonic watery secretion released by salivary glands. It also contains antibodies, electrolytes, enzymes, bacterial flora, lymphocytes, neutrophils and epithelial cells

Question 2

In what way do minor glands produce saliva?

Answer 2

Continuously

Question 3

What is the purpose of baseline saliva production?

Answer 3

Reduce friction
Hydrate oral cavity
Prevent bacterial build up

Question 4

What does failure of baseline saliva production result in?

Answer 4

Dry mouth
Halitosis (bad breath)
Poor dental hygiene

Question 5

In what way do mass-ejecting glands produce saliva?

Answer 5

Intermittent production of large amounts of saliva

Question 6

What is mass release of saliva triggered by?

Answer 6

Thought, smell, sight and taste of food

Question 7

What are the three pairs of mass-ejecting glands called?

Answer 7

Parotids
Sublingual
Submandibular

Question 8

What kind of saliva do the parotid glands release?

Answer 8

Serous- thin and watery

Question 9

What kind of saliva do the sublingual glands release?

Answer 9

Mucous saliva- thick and containing mucins

Question 10

What kind of saliva do the submandibular glands release?

Answer 10

Mixed secretions but mainly mucous

Question 11

What is salivation?

Answer 11

The process by which saliva is produced

Question 12

List 4 functions of saliva

Answer 12

Moistening and softening of food
Lubrication of food
Initiates digestion
Detoxification of food
Teeth maintenance
Clearance of oral suagrs

Question 13

What do the parotid glands drain into?

Answer 13

Stenson’s duct and then the oral cavity

Question 14

Which of the mass-ejecting glands are the largest?

Answer 14

Parotid

Question 15

Where are the submandibular salivary glands located?

Answer 15

On the floor of the mouth

Question 16

What is a salivary secretory unit known as?

Answer 16

An acinus

Question 17

Which part of the acinus secretes the saliva?

Answer 17

Acinar cells

Question 18

What happens in the ductal cells of a salivary acinus?

Answer 18

Ions are reabsorbed to produce hypertonic saliva

Question 19

What is the gag reflex?

Answer 19

Substances entering the mouth are rejected by gagging or retching

Question 20

Where does the mouth become the oropharynx?

Answer 20

Posterior to the palatoglossal arch

Question 21

What are the two substages in the oral phase of swallowing?

Answer 21

Preparatory phase

Transit phase

Question 22

What happens in the Preparatory phase of swallowing?

Answer 22

Food is under voluntary control. It is chewed and mixed with saliva to form a bolus. It ends when the food is positioned on the tongue for transport.

Question 23

What happens in the transit phase of swallowing?

Answer 23

Begins when the tongue pushes the food upwards and posteriorly. Sensory receptors are then activated.

Question 24

What happens in the pharyngeal phase of swallowing?

Answer 24

Soft palate is raised to close of nasopharynx. Hyoid bone and larynx are raised to close of the airways. The food is forced into the airways. This phase is reflexive.

Question 25

What is the upper oesophageal sphincter?

Answer 25

A 2-3mm zone of elevated pressure between the pharynx and the oesophagus

Question 26

What is the lower oesophageal sphincter?

Answer 26

Located between the oesophagus and the stomach at level T10 where the oesophagus passes through the diaphragm. It is under autonomic control.

Question 27

What controls the oesophageal phase?

Answer 27

Swallowing centres of the brain

Question 28

When does the oesophageal phase start?

Answer 28

When the bolus passes the upper oesophageal sphincter

Question 29

When does the oesophageal phase end?

Answer 29

When the bolus moves past the lower oesophageal sphincter

Question 30

What is the primary peristaltic wave?

Answer 30

A peristaltic wave that starts at the upper oesophageal sphincter as food passes through it.

Question 31

What happens if the primary peristaltic wave does not clear the food out of the oesophagus?

Answer 31

A secondary peristaltic wave starts just above the site of distention where the food is stuck.