Deglutition Flashcards
1
Q
Pharynx (what it is, segments of pharynx, and innervation)
A
- muscular tube that connects nasal and oral cavities with the esophagus and larynx
- nasopharynx: from nasal choanae (posterio nasal apertures) to sofe palate
- oropharynx: ends at level of hyoid/epiglottis
- laryngopharynx: ends at laryngeal inlet
- innervation by the pharyngeal plexus (GVA: CN IX, SVE: CN X)
2
Q
Layers of pharynx
A
(external to internal)
- buccopharyngeal fascia, from the visceral layer of the deep cervical fascia
- muscular layers
- circular layer: phayrngeal contrsictors
- longitudinal layer: pharyngeal elevators (stylo-, salpingo, and palatopharngeus muscles)
- pharyngobasilar fascia (aka pharyngeal aponeurosis or tela submucosa)
- pharyngeal mucosa
3
Q
Epiglottis: formed from and functions
A
formed from elastic cartilage
function: prevents aspiration of foreign bodies into larynx
4
Q
Vallecula
A
aka epiglottic depressions, “split traps” to hold saliva and prevent the initiation of swallowing reflex
5
Q
Esophagus: what it does and cervial and thoracic portions
A
- muscular tube that connects pharynx to stomach
- cervical portion (upper 1/3) is skeletal muscle (SVE CN X)
- thoracic portion (lower 2/3) is smooth muscle (GVE CN X, parasympathetic innervation)
- thoracic portion moves food through waves of smooth muscl contractions called peristalsis
6
Q
Esophagus: 2 functional sphincters
A
- upper sphincter (UES): skeletal muscle, opened by swallowing reflex; part of the inferior pharyngeal constrictor muscle
- lower sphincter (LES): smooth muscle; also called the esophagogastric or cardiac sphincter
7
Q
Esophagus: points of contrsiction
A
- cervical constriction: at the pharynx-esophagus junction, forms upper esophageal sphincter
- thoracic constrictions: aortic arch, left 1o bronchus
- diaphragmatic constriction: at esophageal hiatus
8
Q
Movements of deglutition
A
- Stage II transport: tongue pushes bolus back, squeezing against hard palate; volus passes into oropharynx
- Elevation phase: soft palate elevates and seals off nasopharynx; pharynx moves up to encompass bolus; tongue presses against roof of mouth; larynx moves up and forward; epiglottis closes
- pharyngeal phase: pharyngeal constrictors contract to produce “explosive swallowing”; food moves into esophagus
- esophageal phase: bolus moves down through the esophagus by peristalsis
9
Q
Stage II transport
A
- tongue pushes bolus back, squeezing against hard palate; bolus passes into oropharynx
- movement: voluntary
- speed: slow
- Muscles: extrinsic muscles of tongue (CN XII)
- genioglossus
- hyoglossus
- styloglossus
- palatoglossus (CN X)
10
Q
Swallowing reflex
A
- mechanoreceptors in the mucosa of the oropharynx detect liquids/bolus
- afferent signal (GVA) transmitted to brainstem by CN IX
- efferent signal (SVE) transmitted to muscles of the elevation phase
11
Q
Elevation phase
A
12
Q
Soft palate
A
- levator veli palatini (CN X)
- musculus uvulae (CN X)
- tensor veli palatini (CN V3)
13
Q
Pharyngeal elevators
A
- stylopharyngeus (CN IX)
- salpingopharyngeus (CN X)
- palatopharyngeus (CN X)
14
Q
Hyoid/laryngeal elevators
A
- thyrohyoid (C1)
- digastric (CN V/VII)
- stylohyoid (CN VII)
- mylohyoid (CN V3)
- geniohyoid (C1)
- hyoglossus (CN XII)
15
Q
Pharyngeal phase
A
- pharyngeal constrictors contract to produce “explosive swallowing”; food moves into esophagus
- movement: involuntary
- speed: rapid
- muscles: pharyngeal constrictors (CN X)
