Neurology and physiology, Schemes and Mind Maps of Neurology

Download Neurology and physiology and more Schemes and Mind Maps Neurology in PDF only on Docsity! Deglutition (SWALLOWING) GASTROINTESTINAL PHYSIOLOGY: Note #1. 3 of 4 IV) 3. ESOPHAGEAL PHASE Begins when bolus moves past UES Esophagus is very muscular Peristalsis started in pharynx, continues in esophagus Problems with relaxation of LES: o GERD (gastro-esophageal reflux disease) (esophagus passes through diaphragm) o Hiatal hernia (because esophagus passes through diaphragm) Figure 6: Bolus passes esophagus by peristalsis and arrives in stomach (1) Peristalsis (i) Primary peristalsis Continuation of pharyngeal peristalsis (ii) Secondary peristalsis When bolus is stuck o Above bolus:  Stimulates circular layer of muscles  Inhibits longitudinal layer of muscles o Below bolus, descending axons:  Stimulate longitudinal layer of muscles  Inhibit circular layers of muscles Figure 7: Primary and secondary peristalsis in esophagus V) SUMMARY (1) Oral phase Boundaries of oral cavity o Anterior: oral vestibule (space btw. teeth and lips) o Posterior: palatoglossal arch Mastication: o Lateral pterygoid, medial pterygoid, masseter, temporalis m. o Innervated by CN V3 (mandibular br. of trigeminal n.) Salivation: o Chemical digestion o Soften food, form bolus Central trough and downward slope of tongue: o Intrinsic + extrinsic mm. of tongue o Innervated by CN XII (hypoglossal n.) (2) Pharyngeal phase Prevent bolus from going into nasopharynx o Uvula contract o Soft palate is elevated Prevent bolus from going into larynx o Approximate vocal cords → glottis shrinks o Epiglottis covers glottis Ensure bolus enters pharynx o Tighten arches o Elevate pharynx o Squeeze pharynx o Elevate larynx and move anteriorly Pharyngeal peristalsis (3) Esophageal phase Continuation of pharyngeal peristalsis Primary peristalsis o Wave-like continuation of pharyngeal peristalsis Secondary peristalsis o Onset of new peristalsis due to activation of stretch receptors in esophageal wall to ensure bolus moves down o Contract above bolus, relax below