Case 1 Flashcards
What are the three main functions of the mouth?
Mastication, swallowing and speech.
What are the three main stages of swallowing?
Oral, pharyngeal and esophageal.
Which stage of the swallowing process in entirely voluntary?
The oral phase
What is the pharyngeal swallow co-ordinated by? Where is this located?
It is co-ordinated by the swallowing centre on the medulla oblongata and the pons
What are the four stages of the oral phase of swallowing?
Moistening, Mastication, Trough formation and movement of the bolus posteriorly.
What are the three main pairs of salivary glands which cranial nerves innervate each?
Parotid (IX/Glossopharyngeal) and submandibular & sublingual (both innervated by VII/Facial)
What are the five main stages of swallowing?
Anitcipatory, Oral preparatory, Oral voluntary, Pharyngeal and Oesophageal
How man times roughly do we swallow a day?
1000 times a day
What two areas of the brain are involved in salivation in the anticipatory stage?
The amygdala and the cortex
In what stage does mastication occur?
The oral preparatory stage
What is bypassed by drugs absorbed through the mucous membrane of the mouth?
The first pass metabolism in the liver
What controls the movement of the tongue up and back against the palate in the oral voluntary stage?
The cortex and the medulla
What is the last stage of swallowing that is predominantly voluntary?
The oral voluntary stage
What are the five steps of the pharyngeal stage of swallowing?
the narrowing of the opening of the pharynx, the nasopharynx closes, the closing of the opening of the trachea, the opening of the oesophagus and the pharynx pushing food into the oesophagus
What are pulled medially inwards in order to narrow the the opening of the pharynx?
The palatopharyngeal folds.
How is the naopharynx closed?
The levator veli palatini contracts causing the soft palate and the uvula to rise and closes them off.
What apart from the moving of the epiglotis prevents food from entering the trachea?
The pulling together of the vocal folds.
What is the term for the interruption of breathing caused by swallowing?
swallowing apnea
What part of the brain receives all of the mouth’s sensation?
In or near the tractus solitarius.
What nerves supply motor innervation the pharynx
CN 5,9,10 and 12 and some of the superior cervical nerves.
What is the longest stage of swallowing?
The oesophageal stage
What is the nervous control of the oesophageal stage of swallowing?
The medulla and the enteric nervous system.
What type of muscle are the different parts of the oesophagus composed of?
The top third is striated muscle the bottom two thirds smooth muscle
What is the innervation of the different parts of the oesophagus?
The upper third (striated muscle) is innervated by CN 9&10 the lower two thirds (smooth muscle) is is innervated by the myenteric plexus with connection to the vagus nerve
What causes the sequential activation of the pharyngeal and oesophageal muscles in volved in swallowing? What neurotransmitter is used?
the vagus nerve, Ach is the neurotransmitter.
What distinguishes the lower oesophageal sphincter from most other sphincters?
It has no specific sphincteric muscle.
What is the effect of an increased level of blood gastrin on the LES? What puspose does this effect serve?
increases its muscle tone. This prevents reflux via distention as the stomach contracts.
Activation of what rectors innervated by what nerves help maintain the contraction/closure of the LES
Vagal Ach receptor (stimulated by the vagus nerve) and alpha adrenergic receptors (stimulated by sympathetic nerves)
Where is the swallowing pattern generator located?
At the medulla and base of the pons.
What are the two types of nerve in the swallowing pattern generator?
Generator and switching neurons
What is the role of the generator neurons in the swallowing pattern generator?
To trigger and time the swallowing process
What is the role of switching neurons in the swallowing pattern generator?
To distribute the drive to the various motor neurons involved in swallowing
Where are the generator neurons of the swallowing pattern generator located
the dorsal medulla
Where are the switching neurons of the swallowing pattern generator located?
The ventrolateral medulla
Via what nerves is sensory information from the oropharynx, larynx and oesophagus fed back to the swallowing center?
CN5 and 9
Via what nerves does the swallowing pattern generator send impulse to the muscles involved in swallowing?
CN 5, 7, 9, 10 & 12 as well as superior cervical nerves
What are the three types of protective receptors in the oesphagus?
Chemical, Thermal and Mechanical/stretch.
How apart from activating muscles that obstruct the airway does the swallowing center pause breathing?
It also inhibits neurons in the respiratory centre
What type of innervation is responsible for the gag reflex?
Parasympathetic nerves.
How might a thyroid problem cause swallowing problems?
A goitre can apply addition pressure on the area underneath it.
What does odynphagia mean?
Pain during swallowing
What is Achalasia?
When the LES does not relax enough to allow propulsion of the food into the stomach.
Damage to what is the most common cause of Achalasia?
The myenteric pexus.
Describe how the most common complication of Achalasia arise?
The tight LES does not allow the passage of food so it builds up within the oesophagus allowing pathogens to grow within the stored food leading to ulcers around it.
What is scleroderma?
Autoimmune attacking healthy tissues causing the stiffening of the oesophageal and pharyngeal muscles.
What type of bacteria is most commonly associated with aspirational pneumonia?
aerobic gram negative ( the most common are streptococcus pneumonae, haemophilus influenza and Staphlococcus aureus
How much water is typically used in a water swallow test what health professional usually caries it out?
150ml, a speach and language therapist.
In what test for swallowing is a patient made to drink a non toxic form of barium how long does it usual take?
videofluroscopy, roughly 30 minutes
What is one unique strength of videofluroscopy that other swallowing tests lack?
It can show aspiration
What modality does a manometry asses swallowing function via?
pressure