Human disease, Digestive system

Organs of the alimentary canal

• Mouth

• Pharynx or Throat 

• Esophagus

• Stomach

• Small Intestines

• Large Intestines

• Rectum

• Anal Canal

Accessory organs

• Teeth

• Tongue

• salivary glands

• Liver

• Gallbladder

• pancreas

• Mouth

• mechanical breakdown of food

• Pharynx

Throat

digestion begins

in the mouth

amylase

enzyme

for initial degradation of starch

food

bolus, swallowed into the esophagus

Sphincter

at the esophagus/gastric junction prevents food to go back to the esophagus (regurgitation)

Stomach

• Gastric enzymes

• Hydrochloric acid

• CHYME:

• Gastric mucosa protected by a thick layer of mucus

• Gastric enzymes

• initially break down proteins

• Hydrochloric acid

• activates other enzymes from pancreas

• CHYME:

• Moistened, acidic food

Chyme passes

into the initial portion of the small intestine (duodenum)

Pyloric sphincter

• prevents food to back to stomach

• will make sure chime is processed in the stomach before it passes into the duodenum

peristalsis

Chyme moves forward throughout the intestines by means of contractions (from smooth muscle in the wall of intestines)

duodenum

most digestion occurs in the first part of the small intestines

Pancreas (exocrine)

secretes into the duodenum:

• Enzymes to digest carbohydrates, fat and proteins

• Alkaline substance to neutralize the acidic secretion from the stomach

Bile

• Formed in the liver stored in the gallbladder

• Emulsifier reduced big fat droplets into small ones easy to digest (by the enzymes) and absorb

Finally sugars, lipids and amino acids

are absorbed into blood capillaries and lymph vessels in the intestinal wall

• villi

• Intestinal wall arranged to provide maximum surface

Material not digested

passed into the colon

• Absorption of water and minerals continues

cecum

first part of the colon

to which the appendix is attached

appendix

mass of lymphatic tissue

Stomatitis

• Inflammation of the oral mucosa

Cause of Stomatitis

• Local or systemic infection

• strep, gonorrhea, syphilis

• Herpes (type1 and 2)

• Candida

risk factors of Stomatitis

• Immune deficiency

• use of long term ATB

• Candida

thrush

Herpes 1

oral to oral

Herpes 2

genital to oral

symptoms of Stomatitis

swollen mucosa, canker sore, ulcers

canker sore

small circular lesions of with red borders

mouth cancer

• Remains among the ten leading causes of cancer death worldwide

• Linked to tobacco and alcohol

• Cause of 80 to 90 percent is smoking cigarettes, cigars, or pipes, and chewing tobacco

Squamous cell carcinoma

most common form of mouth cancer

Esophagus Cancer

occurs most commonly in men over 60 and is nearly always fatal

risk factors are alcohol and smoking

dysphagia principal symptom

dysphagia

difficulty swallowing

Esophageal varices

varicose (enlarged) veins that develop in the esophagus

affects people who abuse alcohol and have cirrhosis of the liver

most serious danger is hemorrhage

Cirrhosis

the destruction and scarring of tissue impairs blood flow through the liver which elevates pressure in the veins of the abdomen and elsewhere

Esophagitis

• Inflammation of the esophagus

• TX:

  • Non irritating diet, frequent small meals

  • Antacids, acid reducing medications

  • sleep with head elevated

  • avoid eating 2-3 hours before bed

risk factors of esophagitis

obesity, old age, and pregnancy

symptoms of Esophagitis

• Heart burn, resembles pain of heart disease

cause of Esophagitis

• Incompetency of cardiac sphincter (GERD)

• reflux

Hiatal Hernia

• Protrusion of part of the stomach through diaphragm at the point where the esophagus joins the stomach

risk factors of Hiatal Hernia

congenital defect in diaphragm

obesity and smoking

increased intra-abdominal pressure associated with obesity

diagnose of Hiatal Hernia

x-ray, EGD

treatment for Hiatal Hernia

• Surgery

• Non irritating diet.

• Reduce weight if obese

• cholinergic drugs strengthen cardia sphincter

Gastritis

• Inflammation of  gastric mucosa

acute gastritis

• Irritants: aspirin, coffee, tobacco, alcohol

chronic gastritis

• stomach lining does not secrete intrinsic factor and hydrochloric acid

• associated with Def of vit B12

intrinsic factor

is required for the absorption of vitamin B12

hydrochloric acid

aids in protein digestion

Peptic Ulcer

• Ulcer of the stomach and duodenum

• tissue inflammation→necrotic tissue→slough off (hole)

3 main causes of Peptic Ulcers are

Helicobacter pylori, excessive aspirin use, and hypersecretion of stomach acid

complications of Peptic Ulcers

hemorrhage

hemostasis

melena

perforation

serious complication of peptic ulcer

peritonitis

obstruction

scar tissue around ulcer or pyloric sphincter spasm

Gastroenteritis

• Inflammation of stomach and intestines

• Bacteria, virus

• Food poisoning, toxins

• Treatment:

  • Replenish water and electrolytes

  • Antispasmodics

Vomiting

• protective mechanism, a response to the presence of an irritant or infection, a distension, or a blockage. Send message to brain.

vomiting center

• located in the medulla (brain) which stimulates the diaphragm and stomach muscles to contract

• the sphincter at the base of the esophagus opens and gastric contents are REGURGITATED.

Gastric Carcinoma

• Risk Factors

  • Consumption of preserved, salted, cured foods

    • Diet low in fruits and vegetables

  • Helicobacter pylori has been implicated

• Symptoms

  • Frequent bloating, loss of appetite, early satiety, nausea, vomiting, abdominal cramps, excessive gas, and blood in the feces, pernicious anemia

pernicious anemia

no intrinsic factor leading to the def of vitamin B12

Appendicitis

• Inflammation of the appendix

• Rupture of wall à spilling of fecal material à peritonitis

Malabsorption Syndrome

• Can’t absorb fat or other substances

• Main symptom: diarrhea, malnutrition, lack of energy, and cant maintain weight

• Cause:

  • diseased pancreas or blocked pancreatic duct: no lipase

  • liver disease or blocked bile ducts: bile cannot be secreted

  • Defective mucosa cells

• TX:

  • Careful control of diet

  • Nutritional supplements (fat soluble vitamins A D E K)

Malabsorption Syndrome example

• Celiac Disease: can’t digest gluten. Dx made with biopsy and history of signs and symptoms. The onset of the disease usually occurs in infancy.

in absence of lipase

fat cannot be absorbed or digested

celiac disease

cant digest gluten

genetic

Diverticulosis

• Abnormal pouches in the intestinal wall

• risk: age, diet that’s low fiber, family history

Diverticulitis

• Inflammation of diverticula

• Diverticula impacted with fecal material

• pain on left side of abdomen

• antibiotics

Crohn Disease:

AKA as Regional enteritis

• Inflammation and thickening of intestine lining

• Mostly affects the upper colon and distal end of the ilium

• SS:

  • Related to inflammation

  • intestinal walls become thick and rigid-chronic obstruction

  • Pain resembles appendicitis, usually in the lower right quadrant of the abdomen

• Cause: unknown

• TX:

  • Anti-inflammatory meds, Immunosuppressive therapy, antibiotics

Chronic Inflammatory diseases of large Intestines

Crohn Disease: AKA as Regional enteritis

Ulcerative Colitis

Ulcerative Colitis

• Extensive ulceration of colon and rectum

• Most common in young females

• SS: diarrhea with pus, mucus, blood.  Cramp like pain

• X-Ray: lacking of haustra, pipe stem colon

• Cause: autoimmune

• TX:

  • Diet regulations

  • Corticoids, sedatives, surgery (colostomy)

Colon and Rectum carcinoma

• High Incidence in the US

• SS

  • depends on location of the tumor: usually grows slowly and remains localized

  • Change of bowel habits

  • Anemia

• Cause:

  • Ulcerative Colitis and Familial Polyposis

  • Diet high in meat, low in fiber

• Prevention:

  • Colonoscopy after 45 y/o

• DX

  • DRE, proctoscopy, colonoscopy

family polyposis

is a hereditary disease in which numerous polyps develop in the intestinal tract

intestinal obstruction

organic and functional (paralytic)

intestinal obstruction organic

material blockage

intestinal obstruction functional

paralytic

decrease in peristalsis

inguinal hernias

intestine pinches as it protrudes through muscle of body wall

volvulus

intestines twist on itself

adhesions

linking of two surfaces by fibrous scars, occurs following surgery or inflammation

intussusception

a segment of intestine telescopes into the part forward to it

Hemorrhoids

• Varicose veins in the rectum mucosa

• internal or external

• Causes:

  • Heredity, poor dietary habits, inadequate fiber, overuse of laxatives, lack of exercise.

prolapse

hemorrhoid coming through the anal opening

IBS = Irritable Bowel Syndrome

• Common large intestine disease

• function disorder of motility

• Cramps, change in bowel habits, bloating gas

• Not progress to inflammatory disease or Ca

• Cause:

  • Abuse of laxatives

  • Certain foods can trigger it : coffee, alcohol, spicy foods, fatty foods, concentrated orange juice

• TX:

  • Fiber in diet to relieve constipation

  • Tension relieving activities: sports, regular exercise

Dysentery

• Acute inflammation of colon = colitis

• Infectious disease

• SS:

  • diarrhea (pus, blood, mucus).

  • Pain

• Cause:

  • Bacteria, parasitic infections, contaminated water

liver

• Largest glandular organ of the body

• Regenerates when diseased or damaged cells

• Receives dual blood supply:

  • Oxygenated blood

  • Nutrient-rich blood

• Oxygenated blood

• from Hepatic Artery

• Nutrient-rich blood

• from Portal Vein

Jaundice: 

(icterus)

• Usually associated with liver disease

• Excess of bilirubin in blood à yellowish discoloration of skin and mucous membranes

• Bilirubin

• is formed from metabolism of Heme group of RBC

• is conjugated with other chemicals to form Bile. Bile is stored and concentrated in gallbladder

• Bilirubin increases because

• ↑ Heme availability (prehepatic): Hemolytic anemia

• Hepatic conditions

• Obstruction (post hepatic)

Viral Hepatitis

• Jaundice

• Urine color: dark yellow

• Enlarged, tender liver

Hep A

• • Least serious form of hepatitis.

  • Formerly called infectious hepatitis

  • SS: anorexia, nausea, mild fever, jaundice

  • Transmission: fecal-oral, contaminated food and water = poor sanitation

  • Prevention:

    • Active: vaccination

    • Passive:  Immunoglobulin(provides temporary protection after exposure) 

Hep B

• Can produce chronic disease, cirrhosis, fulminating hepatitis

• Formerly called serum hepaptitis

• Prevention:

• Active: vaccination

  • Passive: immunoglobulin: HBIG

• Transmission: blood, sex

Hep C

• Leading cause of chronic hepatitis and cirrhosis

• Transmission: blood mainly, sex

• Tx:

  • Antivirals

  • Most common reason of liver transplant

Hep D

• Defective virus, can only infect liver if it is previously infected with Hep B.

• More  serious than Hep B alone and frequently progresses to chronic disease

Hep E

• Rare in the US

• Produces epidemics in Asia, Africa, Mexico

• Transmission: fecal-oral. Contaminated water

• No vaccines or treatment available

• No evidence to progress to chronic disease

Cirrhosis

• slowly progressing disease in which healthy liver tissue is replaced with scar tissue, eventually preventing the liver from functioning properly

Cirrhosis symptoms

• Jaundice

• Acholia:

• Dark yellow color of Urine:  (Excess of bile transported to the kidneys)

• Abdominal mass and pain in the upper quadrant

• Ascites:

• hepatic ammonia

• hypoalbuminemia

Cirrhosis causes

• Chronic alcoholism: AKA portal cirrhosis, Laennec cirrhosis, nutritional cirrhosis

• Severe chronic hepatitis

• Chronic inflammation of bile ducts

• Certain drugs and toxins: Acetaminophen (tylenol)

• Acholia

• clay colored stools (Bile not secreted into the duodenum)

• Ascites

• distention of the abdomen due to the accumulation of fluids in the peritoneal cavity.