Lecture 10 - Gastrointestinal System

Mouth > pharynx > epiglottis > esophagus > stomach > duodenum > jejunum > ilieum > Ileocecal valve > large intestine > sigmoid colon > rectum > anus

Peristalsis

4

Mucosa, submucosa, muscularis, serosa

Epithelium (epithelial cells), loose connective tissue, and smooth muscle

blood vessels, glands, submucosal plexus

Myenteric plexus, inner circular layer, outer longitudinal layer

Connective tissue and epithelium of peritoneum

1. Ingestion
2. Mastication (chewing)
3. Deglutition (swallowing)
4. Digestion
5. Absorption
6. Excretion

Dental caries, gum disease
Infectious diseases (e.g. gastroenteritis)
Circulatory disorders, hemorrhagic lesions
Multifactorial disorders (e.g. peptic ulcer, inflammatory bowel disease)
Obstructive disorders
Functional disorders (e.g. indigestion, malabsorption)
Neoplasms

general term for inflammation and soreness in the mouth, including the tongue, gums, lips, cheeks, and palate.

Herpesvirus infecction

Thrush (Candida Albicans)

Aphthous Stomatitis (canker sores)

1. Herpesvirus infection
2. Candida albicans infection (thrush)
3. Aphthous stomatitis (canker sores)

it targets non-keratinized surfaces

tobacco chewing (#1 cause)

1. Leukoplakia
2. Erythroplakia
3. Ulcer
4. Crater
5. Nodule

Squamous cell carcinomas

1. Dysphagia
2. Esophageal (retrosternal) pain
3. Aspiration or regurgitation

difficulty swallowing

pain that occurs behind the sternum or breastbone

2-3

Developmental abnormalities: ATRESIA with or without esophageal-tracheal fistula
Hiatal hernia
Motility disorders (achalasia)
Esophagitis
Circulatory disturbances (varices~varicose veins)
Carcinoma

a rare swallowing disorder that makes it difficult for food and liquid to pass from the esophagus into the stomach.

a CONGENITAL disorder in which a baby's esophagus does not form properly during pregnancy.

an abnormal connection between the esophagus and trachea

occurs when part of the stomach moves up into the chest through a hole in the muscular wall called the diaphragm

when the stomach and part of the esophagus “slide” up into the chest

stratified squamous epithelium

columnar epithelium

condition that occurs when the lining of the esophagus is damaged by acid reflux, causing it to thicken and turn red

inflammation of the esophagus

Reflux of gastric juice ("peptic esophagitis")
Infection: viruses, fungi (immunosuppressed persons), bacterial superinfection
Chemical irritants: exogenous chemicals or drugs

Endoscopy: finding a lot of eosinophils in the stomach

4% of all cancers

8,000

Alcohol and tobacco abuse

MEN

POOR: avg survival is 2 years

Upper or lower esophagus

Lower esophagus, developing in Barrett's esophagus

1. Pain: midline, upper abdomen
Vomiting
2. Bleeding: acute with hematemesis (blood in vomit) or chronic with melena (stool has blood - oxidized; upper GI bleeding)
3. Dyspepsia ~ indigestion
Systemic consequences: iron deficiency anemia caused by chronic blood loss, vitamin B12 malabsorption-related megaloblastic anemia.

inflammation of the stomach lining

indigestion

stress, shock, food, exogenous chemicals, drugs
EROSIONS ~ more diffused
ULCERATIONS ~ spots that are damaged into the layers

intestinal metaplasia

Helicobacter pylori (H. pylori)
Autoimmune (with pernicious anemia)

Helicobacter pylori (H. pylori)

an open sore found on the lining of the stomach or duodenum (the first part of the small intestine).

MULTIFACTORIAL

Gastric juice: HCL, pepsin
Mucosal barrier defects: stress, shock, NSAIDs, smoking reduce resistance
H. pylori: found in most patients

duodenum ulcers

In the muscularis because there are a lot of blood vessels here.

25,000 people
causing 14,000 deaths/year
8 x more common in JAPAN & CHILE
Incidence has decreased over past 70 years in the U.S.

Unknown; maybe nitrosamines in food, maybe H. pylori

Developmental abnormalities: Hirschsprung's disease, congenital diverticula (e.g., Meckel's)
Diverticulosis, obstructions, hernias
Vascular disorders
Inflammatory bowel disease
Infections, including peritonitis
Malabsoption syndrome
Neoplasms

a condition in newborns that affects the large intestine (colon) and causes problems with passing stool because the muscles don't work so there is severe constipation. CURE: surgical intervention

Megacolon

a common congenital abnormality where a small pouch that extends from the wall of the small intestine, caused by incomplete closure of the vitelline duct during the fifth week of fetal development

Inflammation in your lower small intestine and part of your large intestine

condition in which pocketS develop on your large intestine

Diverticulosis

Hemerrhoids
Angiodysplasia
Ischemic bowel disease
Chronic ischemia
Acute thrombosis of mesenteria arteries, veins
Nonocclusive intestinal infarts

Valves are leaky

swollen, fragile blood vessels in the colon. (INCREASE DIAMETER).

Older people

Occlusive and non-occlusive formations causes necrosis and bowels do not work.

Number one cause is atherosclerosis. Tissuse starts to die out.

Familial (runs in the family) ++
Peak age 15-25years
Immune disturbances +
Extraintestinal complications + (aka other organs are affected)
Treatment (no cure) +

Distribution: segmental, including ileum and ileocecal (CROHN'S) vs. diffuse, colon ONLY; goes backwards starts at rectum (UC)
Transmural: ++ (CROHN'S) vs. - (UC)
Granuloma: + (CROHN'S) vs. - (UC)
Fistula: + (CROHN'S) vs. - (UC)
Megacolon: - (CROHN'S) vs. + (UC)
Cancer: + CROHN'S vs. ++ (UC)

Crohns

Right side of the intestinal tract. Ileum and Ileosecal valve

Starts at the rectum > sigmoid colon > descending colon > transverse colon > ascending colon (DIFFUSED FORM)

Transmural (affects all)

Mucosa and submucosa (dr. nasr said it)

Crohn's; because inflammation can spread through all the layers in the bowel wall

Crohn's disease

UC

both, mostly UC.

Food poisioning: bacterial toxins ~ salmonella
Viral infections ~ stomach virus, nora virus (cruise ship)
Infectious diarrhea ~ mexico water
Small-intestine infection: E. coli, Vibrio cholerae, Giardia lamblia, rotavirus
Large-intestine infection: E. coli, shigella, norwalk virus, entamoeba

Salmonella

Stomach virus, nora virus (cruise ships)

Water in foreign country

E.coli, vibrio cholerae

E.coli, shigella Sp

Rotavirus

norwalk virus aka norovirus

Giardia lamblia

Entamoeba histolytica

an inflammation of the appendix

a vestigial hollow tube, same tissue as tonsils

pain

inflammation of the peritoneum

Rupture of stomach
Spread of infection from fallopian tubes
Rupture of abscess
Infection of preexisting ascites

Peritoneal effusion aka ascites

fluid builds up in the abdomen aka peritoneal effusion

Acute pancreatitis
Rupture of the gallbladder
Postsurgical peritonitis

Major digestive enzymes

is a rare form of aseptic peritonitis, or inflammation of the abdominal cavity without infectious pathogens

Acute pancreatitis
Rupture of the gallbladder
Postsurgical peritonitis

chronic digestive and immune disorder that damages the small intestine. Loss of villi. It's caused by a sensitivity to gluten

a rare bacterial infection that causes malabsoption due to big inflammation response

Tropheryma whipplei

Deficiency of gastric juices: postgastrectomy conditions, atrophic gastritis
Deficiency of bile: biliary obstruction, liver disease, Crohn's disease
Deficiency of pancreatic juices: chronic pancreatitis
Bacterial overgrowth: G. lamblia

Digest

Celiac sprue
Tropical sprue
Infectious enteritis (e.g., E.coli, rotavirus)
Crohn's disease
Whipple's disease
Congenital abetaliproproteinemia
Short bowl syndrome (after surgical resection)

inherited disease that prevents the body from absorbing fats and certain vitamins from food. fatty stool ewwww.

when the small intestine is unable to absorb nutrients properly after surgery or damage

Colon

Sporadic or familial (S:F = 8:2)
Benign or malignant (B:M = 3:1)
May be Solitary or multiple
Primary or secondary (P > S)

Adenomas, carcinomas

90%; adenomas, carcinomas

Lymphomas or mesenchymal tumors (benign soft tissue tumor, e.g., lipoma, leiomyoma, sarcomas)

3rd most common cancer of internal organs
Affects 190,000 persons per year in the U.S.

Colonoscopy: identifying a napkin-ring lesion because the tumor grows in a circle and narrows the passage

Sigmoid colon