Normal Swallow Flashcards
4 phases of the swallow
Oral prep, oral, pharyngeal, esophageal
Beginning/end of oral prep phase
beginning: when bolus enters the mouth, end: when the bolus is pushed to the roof of the mouth by the tongue
Important anatomy of the oral prep phase
tongue (most important), lips, the jaw
Muscles of mastication and oral preparation of the bolus (oral prep phase)
5 paired muscles: temporalis, masseter, lateral pterygoid, medial pterygoid (all are muscles of mastication), buccinator (responsible to keep the bolus taught/retain pressure in your mouth)
Describe the oral prep phase:
the bolus enters the mouth, the tongue moves laterally, muscles of mastication and jaw create a rotary chew, chew is voluntary at first then becomes reflexive, saliva helps turn the food into a bolus, bolus is centralized and compressed by the tongue and pressed against the hard palate
Describe the oral prep phase with CN innervation:
Open your mouth (CN 5), move food laterally to the teeth and chew (CN 5), centralize the bolus as it mixes with saliva (CN 7) and move it up to the roof (CN 12)
Chewing begins as ____ but then becomes ____
voluntary, reflexive
3 sets of salivary glands
submandibular (underneath the jaw), parotid (top of the teeth), sublingual (under the tongue)
Why is saliva needed
saliva starts the digestion process, adds liquid to the bolus to make it more cohesive /manageable, keeps our mouth clean
Beginning/end of oral phase
beginning: when bolus begins anterior-posterior movement after being pressed against the roof of the mouth, end: when bolus reaches the oropharynx
Buccinator function
Tighten cheeks to molars (CN VII)
Temporalis function
lifts and retracts jaw (CNV3)
Masseter function
elevates jaw (CNV3)
Lateral pterygoid function
side-to-side (CN V3)
Medial pterygoid function
elevation (CN V3)
The border between oral prep and oral phase is iffy. What is one landmark that separates the two:
Faucial Pillars
Describe the oral phase
the bolus moves from the roof of the mouth (hard palate) posteriorly towards the hypopharynx, velum raises
Main CN innervation during the oral phase:
CN XII innervates the muscles of the tongue to help with A>P propulsion
Intrinsic muscles of the tongue (4):
superior longitudinal muscle, transverse muscle, vertical muscle, inferior longitudinal muscle
Extrinsic muscles of the tongue (3 important ones):
palatoglossus muscle, styloglossus muscle, genioglossus muscle (and hyoglossus)
Superior longitudinal muscle
(intrinsic muscle) runs back to front. Meant to shorten the tip of your tongue (raise tip) and create concave depression
Transverse muscle
(intrinsic muscle) underneath the superior longitudinal muscle, responsible for elongation and narrowing
Vertical muscle
(intrinsic muscle) underneath the superior longitudinal muscle, responsible for flattening the tongue
Inferior longitudinal muscle
(intrinsic muscle) bottom of the tongue. shorten tongue/depress tip. Putting the tongue behind the teeth
Palatoglossus muscle
(extrinsic muscle) moves the tongue towards the palate. Helps raise the tongue
Styloglossus muscle
(extrinsic muscle) responsible for lifting the posterior portion of the tongue and pulling it backwards (elevating and retracting)
Genioglossus muscle
(extrinsic muscle) connects to the hyoid bone and lifts everything in the larynx
2 jobs of the pharyngeal phase
airway protection and bolus propulsion