GI Motility Disorders Achlasia Flashcards
GI motility is the result of what 3 neural networks?
- CNS
- ANS
- Enteric
Enteric Nervous system is what:
Neurons located in the gut wall that comprise the intrinsic neural network called the enteric nervous system
CNS and ANS modulates enteric nervous system activities
ok
Enteric nervous system consists of two components. What are they
- Myenteric Plexus
- Meissner Plexus
Myenteric Plexus is present where and is responsible mostly for what?
Present between the circular and myenteric muscle layers.
Responsible mostly for motility
Meissner plexus is located where and is responsible for what?
Located in the submucosa and is responsible for secretion.
Peristalsis (rhythmic contraction) results from what?
Pacing from the pacemaker present in ENS. Pacemaker cells are called interstitial cells of cajal.
Are interstitial cells of cajal neural in origin?
Nope
Where are interstitia cells of cajal present?
Throughout the GI tract
Upper esophageal sphincter consists of what type of muscle?
striated muscle
Body of the esophagus consists of what type of muscle?
Both smooth and striated
Lower Esophageal sphincter relaxation is controlled by what nerve
Vagus Nerve.
What does receptive relaxation of the fundus apply to?
This describes the way the stomach relaxes to accept new food volume
Upper part of teh stomach handles what?
Liquids
Lower part of stomach handles what?
Solids
Food from the antrum empties into the duodenum when food is what size?
Less than 1 mm
What are the two motility patterns of the small bowel?
Fed and fasting
Fasting pattern =
MMC (Migratory Motor Complex)
Whats the point of MMC
Housecleaning, clears anything left in Small bowel and clears any bacteria
Function of fed pattern small bowel movements?
To mix food for absiorption
Achalasia
Failure of the esophagus to relax and allow food to pass.
- Commonly a failure of the Lower esophageal sphincter.
Incidence of achalasia
rare
Etiology of acahalasia
unknowm, potentially autoimmune
What is the pathophys of achalasia
Loss of post-ganglionic inhibitory neurons in the Myenteric Plexus thus shifting the balance to excitatory neurons.
Pathology of achalasia?
Lymphocyte infiltration in the myenteric plexus
Symptoms of achalasia
- dysphagia
- chest pain
- heart burn
- weight loss
- regurgitation of food ( globus- lump in throat)
DX of achalasia
history and physical, endoscopy, barium swallow, manometry
Characteristic finding of barrium swallow?
Dilated Esophagus with bird beaking of distal part
Severe dilatation can lead to
sigmoid esophagus
What the hell is manometry
Measurement of pressure using a special catheter.
Esophageal, antroduodenal and anorectal manometru are the most common
ok
What are the 2 manometric criteria required for dx of achalasia
1) LES fails to relax in response to swallow
2) Aperistalsis in the distal 2/3 of esophagus
- –
Most common tx for achalasia
Heller’s Myotomy
Complications of achalasia
- Malnutrition
- Aspiration
- Malignancy
- – Untreated achalasia is associated with an increased risk of squamous cell esophageal cancer
Diseases associated with achalasia-like motility disorders
1) malignancy
2) Chagas Disease: secondary to trypanosoma cruzi
3) Amyloidosis
4) Sarcoidosis
5) neurofibromatosis
Know diffuse esophageal spasm
Repetitive contractions in the esophagus and prolonged duration contractions.
Nutcracker esophagus
Increased distal peristaltic amplitude and duration
Nutcracker esophagus
Hypercontracting esophagus…increased distal peristaltic amplitude and duration
