Diseases of the Esophagus Flashcards Preview

GI/Nutrition > Diseases of the Esophagus > Flashcards

Flashcards in Diseases of the Esophagus Deck (46)
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1
Q

What is the main physiological function of the digestive tract?

A

To process acquired food and water to meet the nutritional needs of the multi cellular organism

2
Q

What is the single task of the esophagus?

A

To transport the bolus (food/water) from pharynx into the gastric reservoir (sometimes to transport things out)

3
Q

How is swallowing both voluntary AND involuntary?

A

The initial phase is voluntary, but as the bolus is pushed backwards by the tongue to the hypopharynx the involuntary phase of the swallow reflex is triggered

4
Q

How many muscles are required for swallowing

A

More than 50 (oral, pharyngeal, laryngeal, esophageal, and diaphragmatic)

5
Q

What compartments of the body does the esophagus traverse?

A

Cervical, Thoracic, and Abdominal (It is 18-26 cm in length)

6
Q

What four layers make up the wall of the esophagus? How thick is each layer?

A

Mucosa, submucosa, muscularis propria, and adventitia; They each reach 2-4 mm in thickness

7
Q

What outward motion signifies the start of the involuntary phase of swallowing?

A

Upward movement of the “adam’s apple”

8
Q

What is the difference between the inner and outer muscular layer of the esophagus?

A

Inner layer is circular Outer layer is longitudinal

9
Q

Which layer of the esophagus is not fixed, and slides over the other layers?

A

Mucosa layer

10
Q

What are the muscular differences between the upper esophageal sphincter (UES) and the lower esophageal sphincter (LES)?

A

The upper quarter of the esophagus and UES are composed of striated muscle The lower half of the esophagus along with the LES are composed of smooth muscle

11
Q

Which layer of muscle thickens near the LES?

A

Inner circular layer

12
Q

What is the crural diaphragm?

A

Part of the diaphragm around the LES that contributes to the resting tone (also called the external esophageal sphincter)

13
Q

What is peristalsis?

A

Coordinated and propulsive sequential contraction of the esophageal muscle

14
Q

What mechanism allows primary peristalsis to occur?

A

Appropriately timed relaxation of the upper and lower esophageal sphincters

15
Q

Describe the two subtypes of peristalsis?

A
  • Primary - triggered by swallow (associated with pharyngeal contraction and UES relaxation)
  • Secondary - Triggered by esophageal distention (contraction starts proximal to distention)
16
Q

What two nervous processes contribute to peristalsis?

A

Intrinsic: Enteric neural plexus

Extrinsic: Vagus nerve

17
Q

How is proximal esophageal striated muscle peristalsis controlled?

A

Action potential involves calcium release mainly from sarcoplasmic reticulum via T-tubules The peristalsis is generated by the swallowing “central pattern generator” of the brainstem

18
Q

How is distal esophageal smooth muscle peristalsis controlled?

A

Calcium influx from outside and latency gradiant with “dual peripheral innervation” Peristalsis is physiologically regulated as “a wave of inhibition followed by a wave of excitation”

19
Q

Vagal efferents synapse both on _______ and ______ myenteric neurons

A

inhibitory; excitatory

20
Q

How do vagal efferents affect excitatory motor neurons?

A

Predominantly acetylcholine (some substance P) leads to calcium release and depolarization and second messenger pathways

21
Q

How do vagal efferents affect inhibitory motor neurons?

A

Predominantly NO leads to a cGMP dependent pathway which inhibits calcium entry and leads to hyperpolarization (Can also be triggered by vasoactive intestinal peptide)

22
Q

Do layers of the esophageal muscles contract separately or together?

A

Together - they move in a coordinated fashion to propel the bolus

23
Q

What is the most specific esophageal symptom in esophageal disorders?

A

Dysphagia (difficulty swallowing)

24
Q

What kinds of food can lead to dysphagia? Which causes dyphagia first?

A

Solid AND liquid (Solid food is more dependent on peristalsis and will present first with dysphagia)

25
Q

What other symptoms often present with dysphagia and can be used to aid in diagnosis?

A
  • Heartburn
  • Regurgitation (effortless)
  • Odynophagia (pain during swallow and bolus transit)
  • Chest pain (Non exertional and non cardiac)
26
Q

How long after swallowing should pain occur for dysphagia diagnosis?

A

less than 10 seconds

27
Q

What are the differences in dysphagia symptoms based on location?

A
  • Esophageal - Sticks or hangs up after swallow; may have chest pain when stuck
  • Pharyngeal - Difficulty initating swallow; coughing, choking and nasal regurgitation
28
Q

What are the common etiologies of dysphagia? (Mechanical vs. Neuromuscular)

A
  • Mechanical:
    • Peptic stricture (caused by acid reflux)
    • Esophageal ring (acquired or congenital)
    • Cancer
  • Neuromuscular:
    • Achalasia (most important)
    • Esophageal spasm; dysmotility (non-specific)
29
Q

What are some uncommon etiologies of dysphagia? (mechanical vs. neuromuscular)

A
  • Mechanical: Web, diverticulum, tumors, foreign body
  • Neuromuscular: Sclerodoerma; Chagas disease; Collagen Vascular disorders
30
Q

What signs of solid food dysphagia are indicative of cancer? peptic stricture? esophageal rings?

A
  • Cancer: Progressive and age > 50
  • Peptic stricture: Chronic heartburn
  • Esophageal Ring: Intermittent
31
Q

What signs of solid OR liquid food dysphagia are indicative of scleroderma/achalasia? spasm?

A
  • Liquid food dysphagia is often neuromuscular
    • Scleroderma/Achalasia: Progressive with heartburn/regurgitation
    • Spasm: Intermittent and chest pain
32
Q

What can be done diagnostically to identify esophageal disorders?

A
  • Upper GI endoscopy (structural information
  • Esophageal manometry (functional information)
  • Radiography: esophagram (structural and functional)
33
Q

What can you look for during an endoscopy?

A
  • Hypopharynx (observe true and false vocal cords and arytenoids
  • LES open or closed?
  • Obstruction?
  • Is Z line visible?
34
Q

What is esophageal manometry?

A
  • The technique for measurement of esophageal intra-luminal pressures (gold standard for diagnosis of esophageal motor disorders)
  • Time vs. Amplitude of contraction
35
Q
  • How long does the UES relax to allow bolus passage?
  • What is the amplitude of the contraction produced by the primary peristaltic wave?
  • What is the duration and speed of peristalsis?
  • How long does the LES relax to allow bolus emptying into stomach?
A
  • Half a second;
  • 150mmHg;
  • 3-7 sec at a speed of 3-5 cm/sec;
  • relaxes for 3-8 seconds
36
Q

What two processes make up achalasia?

A
  • Impaired relaxation of the LES and increased LES tone
  • Loss of peristalsis in the body of the esophagus
37
Q

What causes abnormal function of LES In achalasia?

A

Due to impaired and then loss of inhibitory (NO) activity

38
Q

What morphology is associated with achalasia?

A
  • Degeneration of ganglion cells in myenteric plexus
  • Inflammatory lymphocytic infilatration
39
Q

How does achalasia present?

A
  • Peak incidence in 7th decade (and 20-30) - Bimodal
  • Dysphagia is predominant symptom (solids and liquids)
  • Heartburn, chest pain, regurgitation and weight loss
  • Food stasis, bacterial fermentation and acidity Accommodative behavior
40
Q

How many modalities are needed for diagnosis of achalasia?

A

Two or three (must be observed structurally AND functionally)

41
Q

What are two different appearances of the barium esophagram that may indicate achalasia?

A
  • Bird beak
  • Sigmoid shape
42
Q

What is the differential diagnosis of achalasia (or what causes secondary achalasia)?

A
  • Malignancy
  • Other infiltrative disorders
  • Chagas disease
  • Para-neoplastic syndromes
  • Autonomic nerve damage
43
Q

What are the three types of therapy for achalasia?

A
  • Pharmacotherapy (NO donors and anticholinergic agents)
  • Endoscopic therapy - Botulinum toxin injection or pneumatic dilation
  • Operative therapy
44
Q

What characterizes an esophageal spasm?

A

Dis-coordinated contraction of the muscularis layer

45
Q

Why is esophageal spasm an issue?

A

It interferes with efficient delivery of food and fluids to the stomach

46
Q

In scleroderma esophagus the esophagus loses much of its ability to ______

A

contract (complete aperistalsis)