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GI Physiology II (Part 1) - Coggle Diagram
GI Physiology II (Part 1)
Swallowing
Oral Phase
Tongue pushes food to the pharynx (voluntary)
Pharyngeal Phase
Food stimulates the swallowing centers of the medulla and lower pons
CN X
CN IX
CN V
Inhibit respiration; Prevent choking
Esophageal Phase
Secondary peristalsis for leftovers
Pathophysiology
Dysphagia: Difficulty in swallowing
Esophageal achalasia: LES does not relax (open)
GERD: LES does not contract (close)
Chewing
Muscles of Mastication
Lateral pterygoid
Temporalis
Medial pterygoid
Masseter
Jaw stretch reflex and jaw closure (muscle spindle)
Peristalsis
Esophagus and Small intestine
Back of bolus: LM relax; CM contract
Front of bolus: LM contract; CM relax
Circular muscle innervation
Front of bolus: NO and Inhibitory motor neuron
Back of bolus: ACh and Substance P and excitatory motor neuron
Stimulant: Distention and chemicals from food
PROPULSIVE MOVEMENT
Cells generating GI motility patterns
Smooth Muscle Cells
Gap junctions for synchronous contraction
EXCEPTIONS: Pharynx, UES, upper 1/3 of esophagus and EAS
Slow waves generate contractions; Spatial summation
Enteric neurons
Hormones and neural stimulation
ONLY AFFECTS AMPLITUDE
Specialized interstitial cells (pacemakers)
ICC-IM = muscle bundles between CM and LM in the stomach and colon
ICC-DMP = muscular plexus of the small intestine
ICC-MY = myenteric plexus all throughout GI tract
Segmentation contractions
Small intestine
MIXING MOTILITY; NO NET MOVEMENT