Oesophageal Function Flashcards
Label the areas of the throat (anatomy)
- Nasopharynx
2.Oropharynx - Hypopharynx
4.Larynx
Esophagus
What areas are striated and smooth in throat?
Pharynx, upper oesophageal sphincter (UOS), upper 1/3 of oesophagus – striated muscle
Lower 2/3 of oesophagus, lower oesophageal sphincter (LOS) – smooth muscle
Phases of swallowing
Oral Phase - Volunatry (striated muscle)
Pharyngeal phase (involunatry striated muscle)
Oesophageal (Invol, striated and smooth muscle)
Oral Phase
- stages and explain
- Prep phase
- form bolus
Mastication via teeth, tongue and cheeks to posotion solids, grind and break down - Salvia
- Lubrication and dissolve (amylase) - Transfer phase
- Tip of tongue moves into contact with hard palate.
Closes off anterior oral cavity
Bolus is pushed back of mouth
Pharyngeal phase
-movement of bolus
Lasts slightly less than 1 second
Bolus enters pharynx from back of mouth
Bolus descends through the pharynx by peristalsis at 30-40 cm/s
UOS relaxes (upper oesophageal spinchter)
Bolus leaves pharynx
CLOSE OFF MOUTH, AIRWAY (Pharyngeal phase)
Tongue pushes against palate; seals back of mouth (oropharynx)
Soft palate elevates, proximal
pharyngeal wall moves medially; seals off upper airway (nasopharynx)
Epiglottis swings down, vocal cords and arytenoids adduct; seals off lower airway (laryngeal vestibule leading into trachea)
Essentially:
Upper oesophageal sphincter closed
Soft palate blocks nasal cavity as upper oesophageal sphincter open and epiglottis blocks the larynx
upper oesophageal spchinter re closes
oesophageal phase
UOS relaxes
Bolus enters oesophagus
oesophageal peristalsis iniated
Normal oesophageal function
- Peristalsis - co ordinatted muscular activity resulting in propagation
Primary Peristalsis:
Initated by swallow, continuation of pharygenal contraction
Secondary peristalsis
No induced by swallowing, result of stimualtion of sensory receptors in the body of oesophagus by retained bolus or gastric acid (invol)
oesophagus layers and what nerve
Inner to outer layers
1. Mucosa and sunmucosa (meissner/submucoslplexus)
- Circular muscle (contraction causes increase in luminal pressure), Auerbach/myenteric plexus
- Longitudal muscle
(contractin causes shortening), Vagus nerve
oesophageal peristalsis
- what nervous system used
Parasympathetic and sympathetic nerves (autonomic nervous system)
Enteric nervous system
- Plexus of nerves embedded in the wall of the GI tract
Submucosal plexus (submucosa)
Myenteric plexus (between circular and longitudinal muscles)
- Can operate autonomously – co-ordination of reflexes
- Also communicates with parasympathetic and sympathetic nervous
systems
Reflux and LOS
LOS - releases gas from stomach
people with reflux want Los tightened but if you Tighten it too much you can’t burp and you get gas bloat.
Control of swallowing
- controled by
Process
Swallowing controlled by both cortex and brainstem BUT CO ORIDINATED by medulla
Swallowing centre in brainstem receives sensory input from receptors in posterior mouth and upper pharynx and also innervates swallowing muscles via cranial nerves
Tests for DISORDER AND DISEASE of oesophgeaus
- Gastroscopy
camera down to see anything anatomically wrong - Barium swallow / video fluoroscopy
- 24h pH study
- have a sensor that goes through nose to sit in oesophagus at Los junction, act like a normal day then push button when you
have symptoms to correlate to what is happening inside oesophagus at the same time - manometry: pressure sensors. sensors only down for a little bit and
get them to swallow foods/liquids
Reflux: What is it
acid comes back up , LOS is in appropriately relaxed (can be due to a number of diff things),
acid coming back up burns lower besophagus
OTHER CONTRIBUTING MECHANISMS of reflux (4)
- Hypotensive LOS i.e. not contracting tight enough
Caffeine, alcohol, chocolate, fats
- Certain medications e.g. beta-blockers, nitrates, calcium channel blockers - Hiatus hernia
Note: Not all people with hiatus hernia have reflux
- Relevant, but not main part of the pathophysiology - Impaired oesophageal peristalsis
- reduced clearance
sometimes as you get older, oesophagus gets tired and peristalsis doesnt really happen and so food can just sit there in oesophagus and sometimes ferments in there creating gas and discomfort
4.Disordered gastric motility
- More acid in fundus
Grades of Hiatus hernia
- Normal flap valve
2-3: Reduced flap valve but no hernia
4: Hiatus hernia with stomach sliding inot chest cavity
SYMPTOMS OF GORD
- Heartburn/chest discomfort
- Burning sensation or discomfort over the chest - Regurgitation
- Food or liquid coming back up into mouth - Sour or bitter taste in mouth
- May be worse soon after eating or lying down (e.g. bed time)
OTHER: Nausea, bloating, trouble swallowing, NOTHING
Why do GORD syptoms occur
pH in oesophagus normally 6-7 (neutral)
Squamous epithelium not able to handle pH of gastric contents (which is 1-2 unless buffered by food)
The oesophageal nerve fibres give a sensation of “burning discomfort” – heartburn
Sensitivity of oesophagus to acid highly variable
Complications of GORD
- Reflux oesophagitis
Some people with acid reflux develop ulceration
This is the most common cause of ulcers in the oesophagus - Oesophageal stricture
Scarring from repeated acid exposure and ulceration - Barrett’s oesophagus (if left untreated)
- Cellular change in oesophageal epithelium due to chronic acid exposure causing cancer
QUESTIONS/ALARMS of patients
Unintentional weight loss
Dysphagia (trouble swallowing)
Odynophagia (pain when swallowing)
Unexplained iron deficiency anemia
Persistent vomitting (blockage?)
Palpable mass or lymphadenopathy
Family history of upper gastrointestinal cancer
Age (older = higher risk for cancer)
Ethnicity
SQUAMOCOLUMNAR JUNCTION
- where is it
- transition between..
Junction between oesophagus and stomach (Also known as Z line)
Transition between stratified squamous epithelium
(oesophagus) and columnar (gastric) epithelium
OESOPHAGITIS
- what is it
- causes
- symptoms
inflammation of the oesophagus
Causes:
1. Reflux
2. Medication
* Bisphosphonates
* Tetracyclines
- Infective
* Candidiasis (fungi)
- viral CMV
Pain/discomfort in chest
Bleeding – haematemesis Dysphagia – difficulty swallowing
PEPTIC STRICTURE
- What is it
- main symptom
- Causes
Prolonged inflammation: fibrosis and scarring
Dysphagia is MAIN symtpom
Causes:
-Reflux oesophagitis (acid exposure = peptic stricture)
-Caustic (Alkali ingestion)
- Radiotherapy
-Surgical (anastomotic)
- cancer
BARRETT’S OESOPHAGUS
- Due to
-How does it change cells - risk factors
Due to Chronic acid exposure.
Oesophageal epithelium (squamous epithelium) transforms to become like gastric epithelium (columnar epithelium with goblet cells)
High risk of suspicion in:
Male, over 50
Increased BMI
Smoker
European
Chronic symptoms
OESOPHAGEAL CANCER
-types
- what are assosicated risks causing OESOPHAGEAL CANCER
- where does each type usually occur in throat
2 types:
1. adenocarcinoma (adenoCa)
- squamous cell carcinoma (SqCC)
Risks:
GORD – risk of Barrett’s – risk of oesophageal adenoCa
Smoking, alcohol, diet – risk of oesophageal SqCC
adenoCa more likely to be in distal oesophagus/GO junction
SqCC more likely higher up in oesophagus
EOSINOPHILIC OESOPHAGITIS
- what happens
- patients usually have history of?
Eosinophils infiltrate the epithelium of oesophagus (causing narrowing of oesophagus and rings)
Allergy-mediated
Patient may have history of atopy: asthma,
hayfever, eczema
ZENKERS
- cause of zenkers
- symptoms
Failure of UOS to relax may be a
mechanism causing Excessive pressure causes the
weakest portion of the pharynx to balloon out
Symptoms: Regurgitation
DIFFUSE OESOPHAGEAL SPASM
- what is it
- symptoms
Non-peristaltic or simultaneous onset of contractions in the oesophagus
Symptoms include chest pain, dysphagia, food bolus obstruction
ACHALASIA
- what is it
-symptoms
-diagnosis tests
-treatment
Degeneration of ganglion cells in the myenteric plexus. Failure of relaxation of the lower oesophageal sphincter and Loss of peristalsis in the distal oesophagus
- Dysphagia for solids and liquids
- Regurgitation
- Chest pain, heartburn, and difficulty belching
Diagnosis tests Gastroscopy
Manometry
Barium swallow
- Inject botulinum toxin into LOS- this allows relaxtion
- Balloon - tears walls open
- Hellers myotomy:
cut muscle from outside (adventitia) in, cut both muscle layers but no further but need sphincter to be tight to prevent reflux so
perform a fundoplication to tighten junction
