ANATOMY AND PHYSIOLOGY

Mouth

The mouth is the starting point in the digestive system. Both mechanical and chemical

digestion can occur here. The teeth grind food for mechanical digestions while the

salivary gland break down for chemically for chemical digestion.

Salivary Glands

The salivary glands release saliva. The saliva breaks down food chemically. You have

three major salivary glands. One on the top of your mouth, one on the bottom and one

that covers both sides. Saliva breaks up food using the enzyme salivary amylas

Esophagus (also Oesophagus)

The esophagus, a muscular tube through which partially digested food travels, connects

the mouth and the stomach. Food goes down the esophagus using peristalsis, a pattern

of muscular movements, contracting and expanding.

Stomach

The stomach's job is to break down large food molecules into smaller pieces, so that

they are more easily absorbed into the blood.

The stomach can give off two or three liters of gastric juices per day. This juice can

even destroy the inner liner of the stomach. This is why the inner lining of the stomach

is replaced every two to three days.

Liver, Pancreas, and Gallbladder

The liver puts bile into the small intestine through the biliary system, using the

gallbladder as a container to hold the extra bile.

The pancreas puts off a fluid containing bicarbonate and several juices, including

trypsin, chymotrypsin, lipase, and pancreatic amylase, as well as nucleolytic juices, into

the small intestine. Both these organs help in the process of digestion.

Small Intestine

The small intestine connects the stomach and the colon or large intestine. It has three

parts. They are the duodenum, jejunum, and the ileum. The walls of the small intestine

are lined with villi. Villi help absorb nutrients and put them into the blood. This is the

main purpose of the small intestine.

Large Intestine (Colon)

The large intestine is used to remove water from solid waste. It is 1.5 meters in length. It

also absorbs some vitamins such as vitamin k.

Human Digestive System

The human digestive system is a complex series of organs and glands that processes

food. In order to use the food we eat, our body has to break the food down into smaller

molecules that it can process; it also has to excrete waste.

Most of the digestive organs (like the stomach and intestines) are tube-like and contain

the food as it makes its way through the body. The digestive system is essentially a

long, twisting tube that runs from the mouth to the anus, plus a few other organs (like

the liver and pancreas) that produce or store digestive chemicals.

The Digestive Process:

The start of the process - the mouth: The digestive process begins in the mouth. Food is

partly broken down by the process of chewing and by the chemical action of salivary

enzymes (these enzymes are produces by the salivary glands and break down starches

into smaller molecules).

On the way to the stomach: the esophagus - After being chewed and swallowed, the

food enters the esophagus. The esophagus is a long tube that runs from the mouth to

the stomach. It uses rhythmic, wave-like muscle movements (called peristalsis) to force

food from the throat into the stomach. This muscle movement gives us the ability to eat

or drink even when we're upside-down.

In the stomach - The stomach is a large, sack-like organ that churns the food and

bathes it in a very strong acid (gastric acid). Food in the stomach that is partly digested

and mixed with stomach acids is called chyme.

In the small intestine - After being in the stomach, food enters the duodenum, the first

part of the small intestine. It then enters the jejunum and then the ileum (the final part of

the small intestine). In the small intestine, bile (produced in the liver and stored in the

gall bladder), pancreatic enzymes, and other digestive enzymes produced by the inner

wall of the small intestine help in the breakdown of food.

In the large intestine - After passing through the small intestine, food passes into the

large intestine. In the large intestine, some of the water and electrolytes (chemicals like

sodium) are removed from the food. Many microbes (bacteria like Bacteroides,

Lactobacillus acidophilus, Escherichia coli, and Klebsiella) in the large intestine help in

the digestion process. The first part of the large intestine is called the cecum (the

appendix is connected to the cecum). Food then travels upward in the ascending colon.

The food travels across the abdomen in the transverse colon, goes back down the other

side of the body in the descending colon, and then through the sigmoid colon.

The end of the process - Solid waste is then stored in the rectum until it is excreted via

the anus.

Digestive System Glossary:

anus - the opening at the end of the digestive system from which feces (waste) exits the

body.

appendix - a small sac located on the cecum.

ascending colon - the part of the large intestine that run upwards; it is located after the

cecum.

bile - a digestive chemical that is produced in the liver, stored in the gall bladder, and

secreted into the small intestine.

cecum - the first part of the large intestine; the appendix is connected to the cecum.

chyme - food in the stomach that is partly digested and mixed with stomach acids.

Chyme goes on to the small intestine for further digestion.

descending colon - the part of the large intestine that run downwards after the

transverse colon and before the sigmoid colon.

duodenum - the first part of the small intestine; it is C-shaped and runs from the

stomach to the jejunum.

epiglottis - the flap at the back of the tongue that keeps chewed food from going down

the windpipe to the lungs. When you swallow, the epiglottis automatically closes. When

you breathe, the epiglottis opens so that air can go in and out of the windpipe.

esophagus - the long tube between the mouth and the stomach. It uses rhythmic

muscle movements (called peristalsis) to force food from the throat into the stomach.

gall bladder - a small, sac-like organ located by the duodenum. It stores and releases

bile (a digestive chemical which is produced in the liver) into the small intestine.

ileum - the last part of the small intestine before the large intestine begins.

jejunum - the long, coiled mid-section of the small intestine; it is between the duodenum

and the ileum.

liver - a large organ located above and in front of the stomach. It filters toxins from the

blood, and makes bile (which breaks down fats) and some blood proteins.

mouth - the first part of the digestive system, where food enters the body. Chewing and

salivary enzymes in the mouth are the beginning of the digestive process (breaking

down the food).

pancreas - an enzyme-producing gland located below the stomach and above the

intestines. Enzymes from the pancreas help in the digestion of carbohydrates, fats and

proteins in the small intestine.

peristalsis - rhythmic muscle movements that force food in the esophagus from the

throat into the stomach. Peristalsis is involuntary - you cannot control it. It is also what

allows you to eat and drink while upside-down.

rectum - the lower part of the large intestine, where feces are stored before they are

excreted.

salivary glands - glands located in the mouth that produce saliva. Saliva contains

enzymes that break down carbohydrates (starch) into smaller molecules.

sigmoid colon - the part of the large intestine between the descending colon and the

rectum.

stomach - a sack-like, muscular organ that is attached to the esophagus. Both chemical

and mechanical digestion takes place in the stomach. When food enters the stomach, it

is churned in a bath of acids and enzymes.

transverse colon - the part of the large intestine that runs horizontally across the

abdomen.

The digestive system carries out six basic processes: 

ingestion 

secretion 

propulsion 

digestion 

absorption

defecation

Ingestion is taking food into the mouth. 

Secretion is the act of expelling a liquid. The cells lining the GI tract secrete about 9

liters (9.5 quarts) of water, acid, buffers, and enzymes each day to lubricate the canal

and aid in the process of digestion. 

Propulsion consists of alternating contraction and relaxation of smooth muscle in the

walls of the GI tract to squeeze food downwards. 

Digestion has two parts, mechanical and chemical. Mechanical digestion is chewing up

the food and your stomach and smooth intestine churning the food, while chemical

digestion is the work the enzymes do when breaking large carbohydrate, lipid, protein

and nucleic acid molecules down into their subcomponents -these and others are the

nutrients-. 

Absorption occurs in the digestive system when the nutrients move from the

gastrointestinal tract to the blood or lymph. 

Defecation is the process of expelling what the body couldn't use.

PATHOPHYSIOLOGY OF BLEEDING PEPTIC ULCER DISEASE

Helicobacter Pylori

Non-Steroidal Anti-Inflammatory Drugs

Release of cytokines, lipopolysaccharides, heat-shock protein enzymes, etc.

Hydrogen ions and pepsin

Topical and systemic effects

Inflammatory cascade initiated (cytokines, lymphocytes, neutrophils, etc.)

Mucosal damage and ulceration

Decreased mucus production,

Decreased blood flow,

Increased neutrophils,

Decreased bicarbonate,

Decreased cell restitution

Bleeding

Melena

Hematemesis

Abdominal Pain

DRUG STUDY

Name of drug Pharmacodynamics

Dosage Adverse effects Contraindications Nursing Responsibilities Rationale

Metronidazole Direct-acting trichomonacide and amebicide that works inside and outside the intestines. It is thought to enter the cells of microorganisms that contain nitroreductase, forming unstable compounds that bind to DNA and inhibit synthesis, causing cell death.

CNS: headache, dizziness, seizuresGI: abdominal pain, anorezia, nausea, diarrhea, dry mouth, furry tongue, glossitis, unpleasant taste vomitingSkin: rashes, urticariaHematologic: leucopeniaLocal: phlebitis at IV siteNeuro: peripheral neuropathyOther: superinfection

- patients with hypersensitivity to metronidazole or other nitroimidazoles.- use cautiously in patients with history of blood dyscrasia, CNS disorder, or retinal or visual changes.Patients- use cautiously in patients who take hepatotoxic drugs or have hepatic disease or alcoholism.

- administer with food or milk. Tablets may be crushed for patients with difficulty swallowing.

- instruct patient to take medication exactly as directed evenly spaced times between dose, even if feeling better. Do not skip doses or double up on missed doses. Id a dose is missed, take as soon as remembered if not almost time for the next dose.

- caution patient about activities that may be requiring mental awareness until response to medication is known.

- caution patient that medication may cause an unpleasant metallic taste.

- to minimize gastric irritation.

- altering the dosage of the medication may cause untoward effects.

- drug may cause dizziness or light-headedness.

- inform patient that medication may cause urine to turn dark.

- advise patient to consult a health care professional if there is no improvement after a few days or if signs such as black furry overgrowth in tongue, or foul-smelling stools develop.

- monitor patient for adverse reactions.

- this may indicate occurrence of superinfection.

Amoxicillin Binds to bacterial cell wall causing cell death; prevents bacterial cell wall during cell wall synthesis

CNS: seizuresGI: pseudomembranous colitis, diarrhea, nausea, vomitingSkin: rashes, urticariaBlood: blood dyscrasiaOther: anaphylaxis, serum sickness, superinfection

Hypersensitivity to penicillins, cephalosporins. Not used to treat pneumonia, bacteremia pericarditis during acute stage.

- obtain pt’s hx of allergy

- Assess pt for any s/s of infection - Assess for pt’s sensitivity to penicillin or other cepalosporins - assess for allergic rxn during therapy

- Assess for bowel pattern.

- allergy to drug or any of its components is a contraindication

- early detection may provide time for prompt intervention- if diarrhea should occur, medication has to be

- monitor patient for hypersensitivity or adverse reactions

discontinued

Omeprazole Omeprazole is converted into metabolites that irreversibly bind and inhibit H+-K+-ATPase (an enzyme on the surface of gastric parietal cells). It inhibits transport of hydrogen ions into the gastric lumen. Omeprazole increases the gastric pH and reduces gastric acid formation.

CNS: drowsiness, dizziness, fatigue, headache, weaknessCV: chest painGI: abdominal pain, acid regurgitation, constipation, diarrhea, flatulence, nausea, vomitingSkin: itching, rashOther: allergic reaction

- Ccontraindicated in patients hypersensitive to drug- use cautiously in patients with liver disease- contraindicated in pregnant women, lactation and children <2 years

- instruct patient to take medication before meals

- caution patient to avoid driving or other activities requiring mental alertness until reaction to drug has been established.- instruct patient to avoid alcohol, products containing aspirin or NSAIDs.

- monitor patient for signs of allergic reactions and adverse effects

- drug may cause occasional dizziness or drowsiness.

- these may cause drug-drug interaction and GI irritation

- early detection provides time for immediate interventions.

MEDICAL MANAGEMENT

Given the current understanding of the pathogenesis of PUD, most patients with

PUD are treated successfully with cure of H pylori infection and/or avoidance of

NSAIDs, along with the appropriate use of antisecretory therapy.

A number of treatment options exist for patients presenting with symptoms

suggestive of PUD or ulcerlike dyspepsia, including empiric antisecretory

therapy, empiric triple therapy for H pylori infection, endoscopy followed by

appropriate therapy based on findings, and H pylori serology followed by triple

therapy for patients who are infected. Breath testing for active H pylori infection

may be used.

Computer models have suggested that obtaining H pylori serology followed by

triple therapy for patients who are infected is the most cost-effective approach;

however, no direct evidence from clinical trials provides confirmation.

Perform endoscopy early in patients older than 45-50 years and in patients with

associated so-called alarm symptoms, such as dysphagia, recurrent vomiting,

weight loss, or bleeding.

SURGICAL TREATMENT

With the success of medical therapy, surgery has a very limited role in the management

of PUD.

Potential indications for surgery include refractory disease. Complications of PUD

include the following:

o Refractory, symptomatic peptic ulcers, though rare with the cure of H

pylori infection and the appropriate use of antisecretory therapy, are a

potential complication of PUD.

o Perforation usually is managed emergently with surgical repair. However,

this is not mandatory for all patients.

o Obstruction can complicate PUD, particularly if PUD is refractory to

aggressive antisecretory therapy, H pylori eradication, or avoidance of

NSAIDs. Obstruction may persist or recur despite endoscopic balloon

dilation.

o Penetration, particularly if not walled off or if a gastrocolic fistula develops,

is a potential complication of PUD.

o Bleeding can complicate PUD, particularly in patients with massive

hemorrhage and hemodynamic instability, recurrent bleeding on medical

therapy, and failure of therapeutic endoscopy to control bleeding.

The appropriate surgical procedure depends on the location and nature of the

ulcer.

o Many authorities recommend simple oversewing of the ulcer with

treatment of the underlying H pylori infection or cessation of NSAIDs for

bleeding PUD.

o Additional surgical options for refractory or complicated PUD include

vagotomy and pyloroplasty, vagotomy and antrectomy with

gastroduodenal reconstruction (Billroth I) or gastrojejunal reconstruction

(Billroth II), or a highly selective vagotomy.

IF NOT TREATED

Complications of Bleeding Peptic Ulcer Disease

Bleeding from granulation tissue Erosion of ulcer into an artery or vein

HEMORRHAGE

Sudden onset of weakness

Dizziness Thirst Cold and moist skin

Desire to defecate

Passage of loose, tarry, or even red stools and coffee-

ground emesis

Excessive blood loss

Circulatory shock

Edema, spasm or contraction of scar tissue

OBSTRUCTION

Interference with the free passage of gastric contents through the pylorus

or adjacent areas

Feeling of epigastric fullness

And heaviness after meals

SEVERE OBSTRUCTION

Vomiting of undigested food

Ulcer erodes through all the layers of the stomach or duodenum

PERFORATION

Gastrointestinal contents enter the peritoneum

PERITONITIS Penetrate adjacent

Symptoms:

Radiation of pain into the lower back

Severe night distress

Inadequate pain relief from eating food or taking antacids

Bowel obstruction

Translocation of fluid into

peritoneal cavity and into bowel

Nausea and vomiting

Further losses of fluid

Hypovolemia and shock

Note: if peritonitis progresses and is left untreated, it leads to toxemia and shock, and

eventually death.

PERITONITIS

Reflex muscle guarding

Abdomen is rigid, often described as board-like

Breathing is shallow

Vomiting

Fever

Elevated WBC count

Tachycardia

Hypotension

Irritation of phrenic nerve

Hiccups

PARALYTIC ILEUS ABDOMINAL DISTENTION