DSA Ch. 17 1-3 (Dobson) Flashcards
Importantly, because many organs develop simultaneously during embryogenesis, the presence of congenital GI disorders should prompt what?
Evaluation of other organs!
This is a common congenital anomaly that occurs in one out of every 3,500 live births. It is commonly associated with other congenital malformations, particularly cardiac defects.
Tracheoesophageal (TE) Fistula
________ _______ is a related congenital malformation with a presentation similar to that of a TE fistula and can occur with or without the presence of a fistula.
Esophageal Atresia
Esophageal Atresia consists of a thin, noncanalized cord that replaces a segment of the esophagus, most commonly at the tracheal bifurcation. It is usually associated with a _________ connecting the upper or lower esophageal pouches to a bronchus or trachea.
Fistula
***Can also be fistula without atresia (TE fistula)!
TE fistulas occur due to abnormal septation of the caudal foregut during which weeks of embryonic development?
4th and 5th weeks
In embryonic development, the trachea normally forms as a _________ of the foregut and develops a complete septum that separates the esophagus from the trachea.
Diverticulum
This occurs in the Ileum, and is due to the failed involution of the Vitelline Duct (which connects the lumen of the developing gut to the yolk sac).
Meckel Diverticulum
The mucosal lining of Meckel diverticula may resemble that of normal small intestine, but ectopic ________ or ________ tissue may also be present. The latter may secrete acid, cause peptic ulceration of adjacent small intestinal mucosa, and present with occult bleeding or abdominal pain resembling acute appendicitis or obstruction.
Pancreatic
Gastric
What are the rule of 2’s for Meckel Diverticulum?
- 2% of population
- Within 2 ft. of Ileocecal valve
- Approx. 2 inches long
- 2x more common in males
- Symptoms by age 2 (usually)
***Although, only 4% of cases every show symptoms at all!
This occurs when there is thickened muscle around the pylorus, preventing food from leaving the stomach.
Pyloric Stenosis
Pyloric Stenosis occur 3-5x more often in males, and also has a much higher rate of concordance in (DIZYGOTIC/MONOZYGOTIC) twins, with a 200-fold increase if one of the twins is affected. In (DIZYGOTIC/MONOZYGOTIC) twins, there is just a 20-fold increase in risk for siblings of affected individuals.
Monozygotic
Dizygotic
What chromosomal syndromes give an increased chance of Pyloric Stenosis?
Turner Syndrome
Edward Syndrome
What antibiotics can give an infant increased risk of developing Pyloric Stenosis? Consumed either orally or via mother’s milk in their 1st 2 weeks of life.
Erythromycin
Azithromycin
This disease occurs in approximately 1 of 5000 live births, and occurs when normal migration of NCCs from cecum to rectum is arrested prematurely or when enteric ganglion cells undergo premature death.
Hirschsprung Disease (Aganglionic Megacolon)
Hirschsprung Disease may be isolated or occur in combination with other developmental abnormalities. 10% of all cases occur in children with _______ _______ and serious neurologic abnormalities are present in another 5%.
Down Syndrome
Hirschsprung Disease produces a distal intestinal segment that lacks which plexuses?
Meissner Submucosal Plexus
Auerbach Myenteric Plexus
In Hirschsprung Disease, coordinated peristaltic contractions are absent and functional occurs, resulting in _________ proximal to the affected segment.
Dilation
***This is what causes megacolon!
In Hirschsprung Disease, the ________ is always involved.
Rectum
Hirschsprung Disease is more common in males, but when it occurs in females what happens?
Females have longer length of colonic involvement
After birth, what occurs that makes us suspicious of Hirschsprung Disease?
Failure to pass meconium
Intrinsic innervation of much of the alimentary canal is provided by the _______ _______ _______, which runs from the esophagus to the anus, and contains approximately 100 million motor, sensory, and interneurons (unique to this system compared to all other parts of the PNS). These neurons are grouped into two plexuses.
Enteric Nervous System
This plexus lies in the muscularis layer of the alimentary canal and is responsible for motility, especially the rhythm and force of the contractions of the muscularis.
Auerbach Myenteric Plexus
This plexus lies in the submucosal layer and is responsible for regulating digestive secretions and reacting to the presence of food.
Meissner Submucosal Plexus
The ________ develops from the cranial portion of the foregut and is recognizable by the 3rd week of gestation. Development of the GI system results from a series of highly regulated biochemical processes and folding patterns.
Esophagus
The GI tract is subdivided functionally into what?
Foregut
Midgut
Hindgut
The esophagus is a muscular tube that is how long (in adults)?
18-22 cm
What provides the blood supply to the esophagus?
Upper 1/3 = Inferior Thyroid A.
Middle 1/3 = Branches of Thoracic Aorta
Lower 1/3 = Left Gastric A.
What provides nerve supply to the esophagus?
Sympathetic Trunks
Parasympathetic Nerve - Vagus
What is the function of the esophagus?
Move bolus of food from mouth to stomach
***Motility!
If a patient presents with difficulty and/or pain with swallowing stating that “food or liquid gets stuck” then what issue should we think of?
Upper GI obstruction or inflammation
If a patient presents with chest pain or says it feels like “heart burn”, or they are coughing, choking, and have a sour taste in their mouth, what issue should we think of?
If they have chest pain, HAVE to rule out MI first!
Otherwise, think incompetence of LES or reflux of gastric acid.
If a patient presents with “fatigue” and are lightheaded/fainting with pallor, what should we think of?
Blood loss/anemia
If a patient presents with weight loss, what should we think of?
Inadequate nutrition or cancer
What are the types of esophageal obstruction?
Functional
Structural/Mechanical
Achalasia
_________ causes of esophageal obstruction create disruptions in coordinated peristalsis.
Functional
This is a type of functional esophageal obstruction where patients have high-amplitude contractions of the distal esophagus that are, in part, due to loss of the normal coordination of inner circular layer and outer longitudinal layer smooth muscle contractions.
Nutcracker Esophagus (Jackhammer Esophagus)
This is a type of functional esophageal obstruction that presents as repetitive, simultaneous contraction of the distal esophageal smooth muscle.
Diffuse Esophageal Spasm
LES dysfunction consists of high resting pressure or incomplete relaxation, and is often present in many patients with Nutcracker Esophagus or Diffuse Esophageal Spasm. How does LES dysfunction differ from Achalasia?
Achalasia does this, but also includes reduced esophageal peristaltic contractions.
This is a disease that can also cause functional esophageal obstruction due to CREST syndrome.
Systemic Sclerosis
Another functional esophageal obstruction can be from complications due to increased intraesophageal pressure. An example of this is ________ ________.
Zenker Diverticulum
***Like a balloon animal, squeeze on one end then it balloons on the other end!
Zenker Diverticulum is located right above the UES. What are the symptomatic differences from small or large Zenker Diverticula?
Small – Usually asymptomatic
Large – Can trap food and cause regurgitation and halitosis
Structure/Mechanical esophageal obstruction is due to stricture or stenosis that is either ________ or not ________ related.
Cancer
Cancer
What are the “not cancer” causes of structure/mechanical esophageal obstruction?
- Esophageal Webs
- Esophageal Rings
- Achalasia
- Inflammation and scarring (esophagitis)
This type of structural esophageal obstruction is an idiopathic ledge-like protrusion of mucosa that may cause obstruction. They are uncommon, and occur most often in females over 40 yo.
Esophageal Webs
The main symptom of esophageal webs is non progressive ________ associated with incompletely chewed food.
Dysphagia
In the upper esophagus, webs may be accompanied by IDA, glossitis, and cheilosis as part of the _______ or _______. With these, there is also a risk of esophageal cancer!
P-B-K (Paterson-Brown-Kelly)
P-V-S (Plummer-Vinson Syndrome)
What are other disease associations with Esophageal Webs?
- GERD
- C-GVHD
- Celiac Disease
Esophageal Rings are called _______ ______, and are categorized as type A or type B. These rings are circumferential and thicker, and include the mucosa, submucosa, and occasionally hypertrophic muscularis propria.
Schatzki Ring
This type of Schatzki Ring (Esophageal Ring) is present in the distal esophagus above the gastroesophageal junction and covered in squamous mucosa.
Type A rings