Upper GI tract structure and function

Question 1

How is mastication controlled?

Answer 1

Voluntary: somatic nerves control skeletal muscles of the mouth and jaw.
Reflex: automatic when food is in mouth.

Question 2

What prevents food from entering the nasal cavity?

Answer 2

Soft palate

Question 3

What prevents food from entering the lower respiratory tract?

Answer 3

Epiglottis and vestibular folds.

Question 4

Which glands produce saliva?

Answer 4

Parotid,submandibular and sublingual.

Question 5

What are the components of saliva?

Answer 5

Water, mucins, alpha-amylase,electrolytes and lysozyme.

Question 6

What is the parasympathetic control of salivary secretion?

Answer 6

Facial and glossopharyngeal nerves

stimulation causes profuse salivary secretion.

Question 7

What is the sympathetic control of salivary secretion?

Answer 7

Stimulated by adrenoreceptors.

Question 8

Is salvation affected by vagus?

Answer 8

Nope

Question 9

What is the reflex control of salivary secretion?

Answer 9

Food in the mouth activates chemoreceptors.

Question 10

What are the functions of the stomach?

Answer 10

Temporary store of ingested material.
Dissolve food particles and initiate digestive process.
Control delivery of contents to small intestine.
Sterilise ingested material.
Produces intrinsic factor for B12 absorption.