GI Disorders

Question 1

What are some disorders affecting the oral cavity and swallowing?

Answer 1

• Xerostomia

* Dysphagia

Question 2

What is Xerostomia?

Answer 2

DRY MOUTH
Hyposalivation or excessive clearance:
- Anxiety
- Sjogren’s syndrome
- damage to salivary glands
- cancer treatment
- dehydration

Question 3

What is the most common cause of Xerostomia?

Answer 3

Medications!

eg. antihistamines, antidepressants, antihypertensives, anti-Parkinson agents

Question 4

What treatment is used to treat xerostomia?

Answer 4

Saliva substitutes.

Pilocarpine
muscarinic receptor agonist, increases exocrine secretion

Question 5

What is Dysphagia?

Answer 5

Swallowing disorder! (disruption in swallowing process):
[reduced laryngeal closure → aspiration]

• Problem can occur at any stage of swallowing
• Range from:
• –Total inability to swallow
• –Coughing/choking because some food/liquid enters windpipe (aspiration)

Question 6

Why is Dysphagia a serious threat to health?

Answer 6

• Aspiration
• Pneumonia
• Malnutrition
• Dehydration
• Weight loss
• Airway obstruction

Question 7

What are some neurological conditions that may lead to Dysphagia?

Answer 7

• Stroke (most common)
• Traumatic brain injury
• Cerebral palsy
• Parkinson disease and other degenerative neurological disorders

Question 8

What are some disorders affecting the Oesophagus and Stomach?

Answer 8

• Reflux

* Peptic ulcers

Question 9

What causes Reflux Oesophagitis (heartburn)?

[How can the acid defy gravity?]

Answer 9

If gastro-oesophageal sphincter RELAXED, upon inspiration:

• intrapleural P decreases
• oesophagus expands

THUS, lower P in oesophageal lumen pulls acidic stomach contents into the oesophagus!

Question 10

How is Reflux Oesophagitis (heartburn) treated?

Answer 10

With agents that neutralise acid or reduce acid production by the stomach!
Including:
- antacids
- histamine receptor antagonists
- proton pump inhibitors

Question 11

How can the bact. Helicobacter pylori withstand the acidic stomach?

Answer 11

1. Reside in mucus layer
2. Settle in antrum (no acidproducing cells)
3. Produce urase (breaks down urea into ammonia – buffers)

Question 12

What type of bact. contribute to the formation of peptic ulcers?

Answer 12

Helicobacter pylori

Question 13

How do H. Pylori contribute to ulcer formation?

Answer 13

1. Secreting toxins that cause persistent inflammation (gastritis) at the site of infection
2. Disrupting the tight junctions between epithelial cells, allowing acid to penetrate
3. Increasing gastrin release by keeping pH up in antrum

Question 14

What disorders affect the accessory organs?

Answer 14

• Biliary obstruction

* Pancreatitis

Question 15

What is biliary obstruction?

What a result of biliary obstruction?

Answer 15

Blockage of any duct that carries bile from the liver or gallbladder to S.I.

Result = jaundice

Question 16

What is the most common cause of biliary obstruction?

Answer 16

Choleliths!

(Other causes include:

• malignancy
• infection
• biliary cirrhosis)

Question 17

What causes jaundice?

Answer 17

Bilirubin (break down product of old red blood cells) can not be eliminated in the faeces and accumulates in body!

Question 18

What is Pancreatitis?

Answer 18

INFLAMMATION OF PANCREAS!

– pancreatic enzymes irritate and damage the pancreas itself (can be acute or chronic)

Question 19

What damage does pancreatitis cause?

Answer 19

Tissue loss
Necrosis
Pain

Question 20

What causes pancreatitis?

Answer 20

Results mainly from:

• alcoholism
• certain drug use
• duct blockage (most often from gall stones)

Question 21

What are some disorders affecting the S.I.?

Answer 21

• Gluten allergy (CELIAC DISEASE)

* Lactose intolerance

Question 22

What is Celiac disease?

Answer 22

(Gluten enteropathy)

Abnormal gluten sensitivity causes a T-cell mediated inflammatory response upon ingestion causing destruction of villi!

If villi and microvilli are damaged –>
decreased SA of S.I. –>
indiscriminate impairment of nutrient absorption

Question 23

What are some disorders affecting the L.I.?

Answer 23

• Inflammatory bowel disease (IBD)

* Diverticula

Question 24

What is Lactose Intolerance?

Answer 24

Inability to breakdown lactose
(due to lack of lactase molecule in S.I.)

THUS, lactose is fermented by bact. in L.I.

• produces gas & acids
• leads to flatulence & abdominal pain

Question 25

What is Inflammatory bowel disease (IBD)?

Answer 25

ULCERATIVE COLITIS

• Inflammation is contained to mucosal layer
• Loss of tight junctions disrupts ion movement  increased water in lumen
• Exposure to microbiome leads to inflammatory signal

Question 26

What is Diverticula?

Answer 26

Herniations protruding through the smooth muscle at openings created by vasa recta in wall of the colon

• Create small pouches lined by mucosa
• Most often found sigmoid colon –> region with highest intraluminal P’s

Question 27

What are the 2 types of Diverticula?

Answer 27

Diverticulosis

Diverticulitis

Question 28

What is Diverticulosis?

Answer 28

Having the condition of uninflamed diverticula!

– Cause not yet conclusive but associated with a low-fibre diet, constipation, and obesity

Question 29

What is Diverticulitis?

Answer 29

Inflammation of one or more diverticula!

– May be caused by:
trapped faecal material → obstruction → distension, mucous secretion and bacterial overgrowth → vascular compromise and perforation OR ↑ intraluminal pressure or dried food particles cause erosion → inflammation, focal necrosis, and perforation

– If severe, can cause intestinal rupture or peritonitis