1.5.1 Gastrointestinal Motility and Dysmotility I Flashcards
What is the role of bicarbonate in the saliva?
Protects erosion of teeth, neutralizes gastric secretions that reflux
How does the tongue aid in the propulsion of food?
Tip of the tongue presses against the palate lateral regions form seals with alveolar ridges
Tongue will also aid in creation of negative pressure
How does the cricopharyngeus muscle coordinate with other muscles?
When there is a signal to swallow - it will relax and the other muscles will contract to move the bolus of food.
What is zenker’s diverticulum?
Herniation between inferior pharyngeal constrictor and cricopharyngeus
Can lead to retention of food in the pouch, foul breathe and increased intrabolus pressure during swallowing
What is the importance of the intrabolus pressure?
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.
What are some functional changes associated with oropharyngeal dysmotility in the pharyngeal phase?
What is this an example of?
Failure of the UES to relax
What is this an image of?
Salivary glands
What are the 3 salivary glands?
Parotid (20%) - largest, serous
Submandibular (70%) - mucous and serous
Sublingual - Mucous and serous
How will a cricopharyngeal bar affect intrabolus pressure?
Vasodilation of the glands does what to the production of saliva?
Increases the production of saliva
Explain the neural control of swallowing.
Initiation is under voluntary control
Bolus activates afferent nerves which signal to the swallowing center
This will then send the proper signals for swallowing
What are some of the mechanisms involved in preventing aspiration?
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
What are the two categories of dysphagia?
functional deficit or pathological disorder
What is a cricopharyngeal bar?
Explain the pharyngeal stage of swallowing
- 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.
- The posterior tongue continues to move the bolus backward. The hyoid bone and larynx move forward and upward. The epiglottis is tipped downward.
- 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).
- 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.
What is the role of proline rich proteins in saliva?
Antimicrobial properties
Acinar cells of the ducts are stimulated by?
These are serous cells and are stimulated by ACh, NE, substance P and VIP
How does stress effect UES pressure?
the anticipatory rise in UES pressure will be a result of stress
What are functional changes of the oral phase in oropharyngeal dysmotility?
Abnormal bolus control before swallowing
Imparied swallow initiation - neuronal
Abnormal bolus transport - tongue dysfunction
Describe the oral stage of swallowing
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
Duct cells secrete what and are stimulated by?
Secrete bicarbonate and are stimulated by ACh and NE
What is dysphasia?
Difficulty or inability to swallow
What is the difference between these two images?
When compared with the normal cricopharyngeus muscle, the muscle from patient with Zenker’s demonstrates fiber dropout
WHat is the role of amylase in saliva?
Break down oligosaccharides
Superior and anterior movement of the hyoid and larynx allow for what?
Opening of the UES following relaxation of the needed muscles
What is are some disorders in oropharyngeal swallowing?
What is the role of mucins in saliva?
lubrication and modulation of adhesion of microorganisms
What is the nadir UES?
THe lowest pressure durin relaxation - higher than normal can indicate diminished UES relaxation
Explain the differences between inhalation, swallowing, and vomiting in regards to the internal components.
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.
What are some of the disorders of the UES?
What is the importance of the cricopharyngeus muscle?
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
