Upper GI Tract Structures and Function

Question 1

What is chewing’s main physiological purpose?

Answer 1

To defend against respiratory failure

Question 2

Which nerves control voluntary chewing?

Answer 2

Somatic nerves

Question 3

What 3 pairs of glands secrete saliva?

Answer 3

Parotid
Submandibular
Sublingual

Question 4

What are the 5 main constituents of saliva?

Answer 4

Water
Mucins - lubricant
a-Amylase - cattalyses breakdown of polysaccharides
Electrolytes - regulates pH
Lysozyme - bacteriocidal

Question 5

Which 2 nervous systems control salivary secretion?

Answer 5

Sympathetic and Parasympathetic

Question 6

What is the effect of parasympathetic stimulation on salivary secretion?

Answer 6

Produces profuse watery salivary secretion

Question 7

What is the effect of sympathetic stimulation on salivary secretion?

Answer 7

Produces small viscous salivary secretion

Question 8

Is the 4th layer in the esophagus; serosa or adventitia?

Answer 8

Adventitia

Question 9

What type of epithelium lines the mucosa in the esophagus?

Answer 9

Stratifies squamous epithelium

Question 10

Does the esophagus contain mucous glands in the submucosa?

Answer 10

Yes

Question 11

What occurs in the oral phase of swallowing?

Answer 11

The bolus (food) is pushed to the back of the mouth by the tongue

Question 12

What effect does the presence of a bolus have on the pharynx?

Answer 12

It causes a sequence of reflex contractions of pharyngeal muscles?

Question 13

Where are the contractions of pharyngeal muscles co-ordinated from?

Answer 13

Medulla

Question 14

What is the name of the structure that relaxes allowing food to pass into the esophagus?

Answer 14

Upper esophageal sphincter

Question 15

What does the upper esophageal sphincter do after the bolus has entered the esophagus and why?

Answer 15

Contracts to prevent food reflux

Question 16

What is the name of the process that propels the bolus from the esophagus to the stomach?

Answer 16

Peristalsis

Question 17

Which sphincter relaxes to allow the bolus to enter the stomach?

Answer 17

Lower esophageal sphincter

Question 18

What process occurs immediately after the bolus has entered the stomach?

Answer 18

Relaxation of the stomach

Question 19

Which nerves innervate the relaxation of the elastic smooth muscle of the gastric fundus and body of the stomach?

Answer 19

Vagal nerves

Question 20

What are the 5 basic functions of the stomach?

Answer 20

Temporary storage
Dissolve and begin to digest food
Control delivery to small intestine
Sterilise ingested materials
Produce intrinsic factor

Question 21

What sphincter allows entering of food to the duodenum?

Answer 21

Pyloric sphincter

Question 22

What is the name of the submucosal and mucosal folds in the stomach?

Answer 22

Mucosae

Question 23

Is the outer layer of the stomach; serosa or adventitia?

Answer 23

Serosa