1.5.1 Gastrointestinal Motility and Dysmotility I

Question 1

What is the role of bicarbonate in the saliva?

Answer 1

Protects erosion of teeth, neutralizes gastric secretions that reflux

Question 2

How does the tongue aid in the propulsion of food?

Answer 2

Tip of the tongue presses against the palate lateral regions form seals with alveolar ridges

Tongue will also aid in creation of negative pressure

Question 3

How does the cricopharyngeus muscle coordinate with other muscles?

Answer 3

When there is a signal to swallow - it will relax and the other muscles will contract to move the bolus of food.

Question 4

What is zenker’s diverticulum?

Answer 4

Herniation between inferior pharyngeal constrictor and cricopharyngeus

Can lead to retention of food in the pouch, foul breathe and increased intrabolus pressure during swallowing

Question 5

What is the importance of the intrabolus pressure?

Answer 5

The intrabolus pressure domain is relatively low and precedes the much higher pressure resulting from the arrival of the pharyngeal contraction coincident with the tail of the bolus. The magnitude of the intrabolus pressure is most dependent on the resistance to flow offered by the UES, in turn determined mainly by the UES diameter during opening and the intrinsic tissue elasticity or compliance within the sphincter.

Question 6

What are some functional changes associated with oropharyngeal dysmotility in the pharyngeal phase?

Answer 6

Question 7

What is this an example of?

Answer 7

Failure of the UES to relax

Question 8

What is this an image of?

Answer 8

Salivary glands

Question 9

What are the 3 salivary glands?

Answer 9

Parotid (20%) - largest, serous

Submandibular (70%) - mucous and serous

Sublingual - Mucous and serous

Question 10

How will a cricopharyngeal bar affect intrabolus pressure?

Answer 10

Question 11

Vasodilation of the glands does what to the production of saliva?

Answer 11

Increases the production of saliva

Question 12

Explain the neural control of swallowing.

Answer 12

Initiation is under voluntary control

Bolus activates afferent nerves which signal to the swallowing center

This will then send the proper signals for swallowing

Question 13

What are some of the mechanisms involved in preventing aspiration?

Answer 13

Rapid and coordinated movements of the bolus through the oral cavity and pharynx

Laryngeal elevation to move out of the way, laryngeal closure, epiglottis inversion

Bolus that does enter though triggers a strong cough

Question 14

What are the two categories of dysphagia?

Answer 14

functional deficit or pathological disorder

Question 15

What is a cricopharyngeal bar?

Answer 15

Question 16

Explain the pharyngeal stage of swallowing

Answer 16

1. The tip of tongue is in contact with the anterior palate. The bolus is propelled backwards between the tongue and soft palate which moves upwards to close off the nasopharynx.
2. The posterior tongue continues to move the bolus backward. The hyoid bone and larynx move forward and upward. The epiglottis is tipped downward.
3. The upper pharyngeal muscle at the posterior wall of the pharynx generates a contraction wave that forces the bolus down into the pharyngeal channel away from the nasopharynx. The distal pharynx relaxes to receive the bolus, the upper esophageal sphincter relaxes, and the trachea is closed off by movement of the glottis (muscles of the larynx also contract and prevent food from entering the trachea).
4. As the bolus moves into the esophagus, the various structures return to their resting positions, e.g., epiglottis turns upward, Hyoid bone and larynx descent, contact can be reestablished with the nasopharynx.

Question 17

What is the role of proline rich proteins in saliva?

Answer 17

Antimicrobial properties

Question 18

Acinar cells of the ducts are stimulated by?

Answer 18

These are serous cells and are stimulated by ACh, NE, substance P and VIP

Question 19

How does stress effect UES pressure?

Answer 19

the anticipatory rise in UES pressure will be a result of stress

Question 20

What are functional changes of the oral phase in oropharyngeal dysmotility?

Answer 20

Abnormal bolus control before swallowing

Imparied swallow initiation - neuronal

Abnormal bolus transport - tongue dysfunction

Question 21

Describe the oral stage of swallowing

Answer 21

Mastication - grinding of the food

Food is mixed with saliva and formed into a bolus

The tongue facilitatates the formation, containment and propulsion of bolus

Question 22

Duct cells secrete what and are stimulated by?

Answer 22

Secrete bicarbonate and are stimulated by ACh and NE

Question 23

What is dysphasia?

Answer 23

Difficulty or inability to swallow

Question 24

What is the difference between these two images?

Answer 24

When compared with the normal cricopharyngeus muscle, the muscle from patient with Zenker’s demonstrates fiber dropout

Question 25

WHat is the role of amylase in saliva?

Answer 25

Break down oligosaccharides

Question 26

Superior and anterior movement of the hyoid and larynx allow for what?

Answer 26

Opening of the UES following relaxation of the needed muscles

Question 27

What is are some disorders in oropharyngeal swallowing?

Answer 27

Question 28

What is the role of mucins in saliva?

Answer 28

lubrication and modulation of adhesion of microorganisms

Question 29

What is the nadir UES?

Answer 29

THe lowest pressure durin relaxation - higher than normal can indicate diminished UES relaxation

Question 30

Explain the differences between inhalation, swallowing, and vomiting in regards to the internal components.

Answer 30

The proximity of respiratory and GI tract has resulted in a complex set of morphologic and reflex adaptations that permit separation of respiratory and GI functions in the aerodigestive tract. **For example, breathing requires airflow between the nose or mouth and trachea. On the other hand, the lungs must be protected from aspiration during swallowing or vomiting by closing the epiglottis and larynx, and movement of fluid out the nose is prevented by sealing the soft palate.**

Question 31

What are some of the disorders of the UES?

Answer 31

Question 32

What is the importance of the cricopharyngeus muscle?

Answer 32

It is a horizontal, **striated** sphincter muscle at top of eso It controls the flow of material between esophagus and pharynx Relaxes as food passes **Tonically contracted state**