GI Swallowing Flashcards
How many phases are there in swallowing and which are voluntary and which involuntary.
- 1) voluntary, 2) involuntary, 3) involuntary
What occurs in phase one of swallowing.
Food is compressed in to roof of the mouth and is pushed back towards the oropharynx. VOLUNTARY.
Which muscles are involved in the first phase of swallowing?
The buccinator muscles- contain food within the oral cavity.
Muscles of mastication- break down food
The suprahyoid muscules- elevate the hyoid and flatten the floor of the mouth pushing the tounge upward.
What occurs in phase 2 of swallowing?
The nasopharynx is closed off by the soft palate.
The hyoid is elevated to shorten and widen the pharynx.
Which muscles close of the nasopharynx?
The muscles of the soft palate- lavtor veli palatini, tensor veli palatini and muscle of the uvula.
Which muscles raise the hyoid and larynx?
The muscles of the floor of the mouth- mylohyoid, hypoglossus and geniohyoid.
What occurs in phase 3 of swallowing?
The sequential contraction of the pharyngeal constrictors.
What is the innervation of the pharyngeal constrictors?
The pharyngeal plexus from CN X and XI.
What causes the gag reflex?
Irritation of the oropharynx.
What occurs in the gag reflex?
Reflex elevation of the pharynx due to irritation of the oropharynx.
What is the reflex arc of the gag reflex between?
CN IX and X.
