GIT - Applied- Dr.Chintan

Salivary glands- Aptyalisn – xerostomia – dry mouth

- Anxiety, fear, sleep, dehydration, fever, atropine- Obstruction due to stone- Radiation therapy

- Sialorrhoea

- Pregnancy, parkinsonism, schizophrenia

Disorders of Swallowing- Paralysis of the Swallowing Mechanism - Dysphagia

- Damage to the 5th, 9th or 10th cranial nerve

- poliomyelitis or encephalitis - damaging the swallowing center in the brain stem

- paralysis of the swallowing muscles - muscle dystrophy, myasthenia gravis or botulism

- Food can go into nose & trachea

- Vomiting – operation – anesthesia - NBM

Disorders of Esophagus- Achalasia is a condition in which the LES fails to relax

during swallowing - food swallowed into the esophagus then fails to pass from the esophagus into the stomach

- damage in the neural network of the myenteric plexus in the lower 2/3rd of the esophagus – no receptive relaxation

- Severe prolonged achalasia – food remain for many hours – enlarged, infected esophagus due to stasis - Megaesophagus

- Ulceration – pain – rupture – death

- Rx – surgical, antispasmodic drug

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Disorders of Esophagus- LES incompetence, which permits reflux of acid

gastric contents into the esophagus (gastroesophageal reflux disease).

- This common condition causes heartburn and esophagitis and can lead to ulceration and stricture of the esophagus due to scarring.

- The condition can be treated by inhibition of acid secretion with H2 receptor blockers or omeprazole

- Surgical treatment

Disorders of the Stomach- Gastritis—Inflammation of the Gastric Mucosa

- chronic bacterial infection of the gastric mucosa

- alcohol or aspirin

- Long standing – gastric atrophy - autoimmunity against the gastric mucosa – achlorhydria – pernicious anemia

- Peptic Ulcer - an excoriated area of stomach or intestinal mucosa caused principally by the digestive action of gastric juice

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Peptic ulcer- imbalance between,- the rate of secretion of gastric juice- the degree of protection afforded by the

gastroduodenal mucosal barrier and the neutralization of the gastric acid by duodenal juices

- (1) excess secretion of acid and pepsin by the gastric mucosa

- (2) diminished ability of the gastroduodenal mucosal barrier to protect against the digestive properties

Peptic ulcer- chronic infection of the terminal portions of the gastric

mucosa and initial portions of the duodenal mucosa, infection most often caused by the bacterium Helicobacter pylori

- Once this infection begins, it can last a lifetime unless it is eradicated by antibacterial therapy

- the bacterium is capable of penetrating the mucosal barrier both by virtue of its

- physical capability to burrow through the barrier- releasing bacterial digestive enzymes that liquefy the

barrier

Peptic ulcer- Psychic disturbances

- smoking, presumably because of increased nervous stimulation of the stomach secretory glands;

- alcohol, because it tends to break down the mucosal barrier;

- aspirin and other NSAIDs that also have a strong propensity for breaking down barrier

Peptic ulcer- Zollinger-Ellison syndrome – gastrinomas – tumors

occur in the stomach and duodenum

- The gastrin causes prolonged hypersecretion of acid, and severe ulcers are produced

- Rx – antibiotic, ranitidine, omeprazole, misoprostol, antacids

- Gastrectomy, vagotomy – complicated bleeding ulcers

- Surgical removal of gastrinoma

Gastrectomy- Severe multiple ulcer, carcinoma, obesity surgery

- Pernicious anemia- Iron deficiency anemia

- Dumping syndrome- Weakness, sweating, dizziness after meals- Hypoglycemia- Hypovolemia- Hypotension

Gastric Function Tests- Fractional test meal- Overnight fasting – RT insertion – fasting sample (free

acidity) – starch meal (total acidity)- Sample also tested for blood, mucus, bile

- Histamine test- Fasting – 0.5 mg Histamine S.C. – 200 ml gastric juice

in 1 hr – 180 ml HCL

- Augmented Histamine test- Number of parietal cells – more in duodenal ulcer –

less in gastric ulcer

Gastric Function Tests- Pentagastrin test- Fasting – BAO – 10 mEq/hr- Synthetic gastrin S.C. – MAO – 25,27 mEq/hr- MAO 50 mEq/hr in duodenal ulcer- MAO normal in gastric ulcer, carcinoma

- Insulin test- Insulin IV infusion – hypoglycemia – vagal stimulation –

gastric secretion- Check for vagotomy

- X-ray Abdomen standing – Gas under right diaphragm

Gastric Function Tests- Barium meal- Swallowing a suspension of radiopaque barium

sulphate- Gastric ulcer – ulcer crater - duodenal ulcer – no crater, - gastric carcinoma – hour glass

- IF estimation

- Endoscopy & Biopsy

Disorders of the Small Intestine- Pancreatic Failure

- (1) in pancreatitis, - (2) when the pancreatic duct is blocked by a gallstone

at the papilla of Vater,- (3) after the head of the pancreas has been removed

because of malignancy

- 60 per cent of the fat entering the small intestine may be unabsorbed, as well as one half of the proteins and carbohydrates

Pancreatitis- Acute pancreatitis or chronic pancreatitis

- The most common cause of pancreatitis is drinking excess alcohol,

- the second most common cause is blockage of the papilla of Vater by a gallstone

- Self digestion – vicious cycle – trypsin inhibitor overcomed

Malabsorption- Sprue – surgical removal

- Nontropical Sprue - idiopathic sprue, celiac disease

- gluten enteropathy, results from the toxic effects of gluten present in certain types of grains - wheat and rye

- gluten has a direct destructive effect on intestinal enterocytes

- Destruction of microvilli first – then villi – reduction of surface area

- Rx - Removal of wheat and rye flour from the diet

Tropical Sprue- occurs in the tropics and can often be treated with

antibacterial agents

- In the early stages of sprue, intestinal absorption of fat is more impaired than absorption of other digestive products.

- The fat that appears in the stools is almost entirely in the form of salts of fatty acids rather than undigested fat - steatorrhea

- The problem is one of absorption, not of digestion

Tropical Sprue- very severe cases of sprue - impaired absorption of

proteins, carbohydrates, calcium, vitamin K, folic acid, and vitamin B12

- (1) severe nutritional deficiency, often developing wasting of the body;

- (2) osteomalacia (demineralization of the bones because of lack of calcium);

- (3) inadequate blood coagulation caused by lack of vitamin K;

- (4) macrocytic anemia of the pernicious anemia type, owing to diminished vitamin B12 and folic acid absorption

Paralytic ileus- Adynamic Ileus

- Direct inhibition of smooth muscles during OT

- Peritoneum irritation

- Intestinal motility ↓- Retention – distension – gas & fluid- Intestinal colic

- Rx: 6 – 8 hrs rest

Disorders of the Large Intestine- Constipation - slow movement of feces through the

large intestine

- dry, hard feces in the descending colon that accumulate because of over absorption of fluid

- Any pathology of the intestines that obstructs movement of intestinal contents, such as tumors, adhesions that constrict the intestines, or ulcers, can cause constipation

- irregular bowel habits that have developed through a lifetime of inhibition of the normal defecation reflexes

Constipation- one does not allow defecation to occur when the

defecation reflexes are excited

- if one overuses laxatives to take the place of natural bowel function,

- the reflexes themselves become progressively less strong over months or years, and the colon becomes atonic

- person should establishes regular bowel habits early in life, usually defecating in the morning after breakfast when the gastrocolic and duodenocolic reflexes cause mass movements in the large intestine

Megacolon- severe constipation - bowel movements occur only once a

week

- allows tremendous quantities of fecal matter to accumulate in the colon, causing the colon sometimes to distend to a diameter of 3 to 4 inches - Hirschsprung’s disease

- lack of or deficiency of ganglion cells in the myenteric plexus in a segment of the sigmoid colon - neither defecation reflexes nor strong peristaltic motility can occur

- The sigmoid itself becomes small and spastic while feces accumulate proximal to this area, causing megacolon in the ascending, transverse and descending colons

Diarrhea- rapid movement of fecal matter through the large

intestine

- Enteritis - inflammation usually caused either by a virus or by bacteria in the intestinal tract.

- Infectious diarrhea - the infection is most extensive in the large intestine and the distal end of the ileum

- the mucosa becomes extensively irritated, and its rate of secretion becomes greatly enhanced - motility of the intestinal wall usually increases manyfold

Diarrhea- Psychogenic Diarrhea - periods of nervous tension

- Ulcerative Colitis

- allergic or immune destructive effect

- strong hereditary tendency

- extensive areas of the walls of the large intestine become inflamed and ulcerated

Diarrhea- The motility of the ulcerated colon is often so great that mass

movements occur much of the day rather than for the usual 10 to 30 minutes

- the colon’s secretions are greatly enhanced

- the patient has repeated diarrheal bowel movements

- Rx – ileostomy - to allow the small intestinal contents to drain to the exterior rather than to pass through the colon for healing

- ulcers sometimes fail to heal - surgical removal of the entire colon

Paralysis of Defecation- defecation is normally initiated by accumulating feces

in the rectum, which causes a spinal cord–mediated defecation reflex

- When the spinal cord is injured somewhere between the conus medullaris and the brain, the voluntary portion of the defecation act is blocked while the basic cord reflex for defecation is still intact

- a small enema to excite action of this cord reflex, usually given in the morning shortly after a meal, can often cause adequate defecation

Dietary fibers- Cellulose, lignin, pectin

- Prevention & Rx of constipation

- Prevent postprandial hyperglycemia – useful in Diabetics

- ↓ blood cholesterol – bind with BS

- ↓ in carcinoma incidence

Vomiting- Vomiting is the means by which the upper GIT rids

itself of its contents when almost any part of the upper tract becomes excessively irritated, over distended, or even over excitable

- Distention or irritation of the duodenum provides an especially strong stimulus for vomiting

- The sensory signals that initiate vomiting originate mainly from the pharynx, esophagus, stomach and upper portions of the small intestines → vagal and sympathetic afferent nerve fibers → vomiting center

Vomiting- “vomiting center” – motor - 5th, 7th, 9th, 10th, and 12th

cranial nerves to the upper GIT

- vagal and sympathetic nerves to the lower tract and through spinal nerves to the diaphragm and abdominal muscles

- antiperistalsis begins to occur often many minutes before vomiting appears

- At the onset of vomiting, strong intrinsic contractions occur in both the duodenum and the stomach, along with partial relaxation of LES, thus allowing vomitus to begin moving from the stomach into the esophagus

Vomiting Act- (1) a deep breath, - (2) raising of the hyoid bone and larynx to pull the

upper esophageal sphincter open, - (3) closing of the glottis to prevent vomitus flow into

the lungs, - (4) lifting of the soft palate to close the posterior

nares

- strong downward contraction of the diaphragm along with simultaneous contraction of all the abdominal wall muscles

Vomiting Act- squeezing the stomach between the diaphragm and

the abdominal muscles, building the intragastric pressure to a high level

- LES relaxes completely, allowing expulsion of the gastric contents upward through the esophagus

- small area located bilaterally on the floor of the 4th ventricle called the chemoreceptor trigger zone (CTZ) for vomiting

- apomorphine, morphine and some digitalis derivatives

Vomiting Act- Destruction of CTZ blocks drug induced vomiting

but does not block vomiting resulting from irritative stimuli in the GIT

- Motion sickness - stimulates receptors in the vestibular labyrinth of the inner ear - brain stem vestibular nuclei – cerebellum - CTZ – vomiting

- Nausea – - (1) irritative impulses coming from the GIT,- (2) impulses that originate in the lower brain

associated with motion sickness

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GIT Obstruction- (1) cancer, - (2) fibrotic constriction resulting from ulceration or

from peritoneal adhesions, - (3) spasm of a segment of the gut, - (4) paralysis of a segment of the gut

- Pyloric obstruction – peptic ulcer – vomiting – alkalosis

- Obstruction beyond the stomach – vomiting – water, electrolytes - dehydration

GIT Obstruction- obstruction is near the distal end of the large

intestine - intense feeling of constipation

- Initially no vomiting – later severe vomiting

- Prolonged obstruction of the large intestine can finally causes rupture of the intestine itself or dehydration

- circulatory shock resulting from the severe vomiting

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FLATUS- (1) swallowed air, - (2) gases formed in the gut as a result of bacterial action, - (3) gases that diffuse from the blood into the GIT

- Most gases in the stomach are mixtures of nitrogen and oxygen derived from swallowed air - gases are expelled by belching

- In the large intestine, most of the gases are derived from bacterial action, including especially carbon dioxide, methane and hydrogen – explosion during OT

- beans, cabbage, onion, cauliflower, corn, vinegar

Lactose intolerance- The low lactase levels are associated with intolerance to

milk

- diarrhea, bloating and flatulence after ingestion of milk

- The diarrhea is due to the increased number of osmotically active oligosaccharide molecules that remain in the intestinal lumen, causing the volume of the intestinal contents to increase

- The bloating and flatulence are due to the production of gas (CO2 and H2) from disaccharide residues in the lower small intestine and colon by bacteria

Thank You…-