Biology
March 25, 2015
Mr. Robert Lewis
Tammy Jeffries
People often refer to the entire abdominal region as “the stomach.” In actuality, the
stomach is an organ located in the upper left part of your abdomen. It is the first intra-abdominal
part of your digestive tract. Your stomach contains several muscles, and can change shape as you
eat or change posture. It plays an instrumental role in digestion. When you swallow, food travels
down your esophagus, passes the lower esophageal sphincter, and enters the stomach. Your
stomach has three jobs: temporary storage of food and liquids, production of digestive juices
and emptying the mixture into the small intestine. How long this process takes depends on the
foods you eat and how well your stomach muscles function. Certain foods, like carbohydrates,
pass through quickly, while proteins remain longer. Fats take the most time to process.
Gastroesophageal Reflux Disease
Reflux is when stomach contents such as food, acid or bile moves back into your esophagus.
When this happens with regular frequency (twice a week or more), it is called gastroesophageal
reflux disease (GERD). This chronic condition can cause pain (heartburn) and irritate the
esophagus lining.
Risk factors include:
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obesity
smoking
pregnancy
asthma
diabetes
hiatal hernia
delay in stomach emptying
scleroderma
Zollinger-Ellison syndrome
Treatment involves over-the-counter remedies and dietary changes. Severe cases require
prescription medication or surgery.
Part 4 of 9: Gastritis
Gastritis
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Biology
March 25, 2015
Mr. Robert Lewis
Tammy Jeffries
Gastritis is when your stomach lining becomes inflamed. Acute gastritis may come on suddenly;
chronic gastritis happens slowly. According to the Cleveland Clinic, eight in 1,000 people have
acute gastritis and two of every 10,000 develop chronic gastritis (Cleveland Clinic, 2013).
Symptoms of gastritis include:
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hiccups
nausea, vomiting
indigestion
bloating
appetite loss
black stool (due to bleeding in the stomach)
Causes include:
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stress
bile reflux from the small intestine
access alcohol consumption
chronic vomiting
use of aspirin or non-steroidal anti-inflammatory medication (NSAIDs)
bacteria or viruses
pernicious anemia
autoimmune diseases
Medications can reduce acid and inflammation. You should avoid foods and beverages that cause
symptoms.
Part 5 of 9: Peptic Ulcer
Peptic Ulcer
If the lining of your stomach breaks down you may have a peptic ulcer. Most are located in the
first layer of the inner lining. An ulcer that goes all the way through the stomach lining is called a
perforation and requires immediate medical attention.
Symptoms include:
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abdominal pain
nausea, vomiting
inability to drink fluids
feeling hungry soon after eating
fatigue
weight loss
black colored stool (tarry stools)
chest pain
Biology
March 25, 2015
Mr. Robert Lewis
Tammy Jeffries
Risk factors include:
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Helicobacter pylori bacteria
excessive alcohol consumption
too much aspirin or NSAIDs
tobacco
radiation treatments
using a breathing machine
Zollinger-Ellison syndrome
Treatment depends on the cause. It may involve medications or surgery to stop the bleeding.
Part 6 of 9: Gastroenteritis
Viral Gastroenteritis
Viral gastroenteritis is when a virus causes your stomach and intestines to become inflamed. The
main symptoms are vomiting and diarrhea. You may also have cramping, headache, and fever.
Most people recover within a few days. The very young, elderly, and people with other diseases
are at increased risk of dehydration.
Viral gastroenteritis is spread through close contact or contaminated food or drink. According to
the U.S. Centers for Disease Control and Prevention (CDC), outbreaks are more likely to occur
in closed environments like schools and nursing homes (CDC, 2011)
Part 7 of 9: Hiatal Hernia
Hiatal Hernia
The hiatus is the gap in the muscle wall that separates your chest from your abdomen. If your
stomach slides up into the chest through this gap, you have a hiatal hernia. If part of the stomach
pushes through and stays in the chest cavity next to the esophagus, it is called a parasophageal
hernia. This less common type of hernia can cut off the stomach's blood supply.
Symptoms of hiatal hernia include bloating, belching, pain, or a bitter taste in the throat. The
cause is not always known, but can be due to injury or strain. Your risk factor is higher if you are
overweight, over age 50, or smoke.
Treatment involves medications to treat pain and heartburn. Your doctor may recommend you
maintain a healthy weight, limit fatty and acidic foods, and elevate the head of your bed. Severe
cases may require surgery.
Part 8 of 9: Gastroparesis
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Biology
March 25, 2015
Mr. Robert Lewis
Tammy Jeffries
Gastroparesis
Gastroparesis is a condition in which your stomach takes too long to empty.
Symptoms include:
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nausea, vomiting
weight loss
bloating
heartburn
Causes include:
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diabetes
medications that affect the intestines
stomach or vagus nerve surgery
anorexia nervosa
postviral syndromes
muscle, nervous system, metabolic disorders
Treatment may include medication and dietary changes. In severe cases, surgery may be
necessary.
Part 9 of 9: Stomach Cancer
Stomach Cancer
Stomach cancer generally grows slowly over the course of many years. In most cases, it begins
in the innermost layer of the stomach lining.
Untreated, stomach cancer can spread to other organs or into the lymph nodes or bloodstream.
The earlier stomach cancer is diagnosed and treated, the better the outlook.
The stomach is located in the upper-left area of the abdomen below the liver and next to
the spleen. Its expanded J shape and three layers of muscle help turn liquid and chewed food
into material suitable for the intestinal tract. When the stomach is empty, the inside has small
folds called rugae. As the stomach expands, these folds disappear to accommodate the new
contents. The average stomach can hold about 1.5 gallons of food and liquid at maximum
capacity. It only holds food for about four hours before passing it along the digestive tract. The
stomach’s main component for digestion is the powerful mix of secretions collectively called
gastric juices. To counteract these strong juices, the stomach protects itself with mucus-like
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Biology
March 25, 2015
Mr. Robert Lewis
Tammy Jeffries
secretions. Without this protection, the stomach would essentially digest itself. Cells in the
stomach create the active ingredients in gastric juices: Pepsin: This protein-digesting enzyme
activates when food enters the stomach. Hydrochloric acid: This extremely strong acid breaks
down food and any other foreign element such as dirt and bacteria. Two muscular rings called
sphincters also provide additional defense against the chemicals in the stomach by moving
contents along. The esophageal sphincter separates the esophagus and the stomach. When that
muscle doesn’t relax properly, it feels like it is difficult to swallow. On the opposite end of the
stomach, the pyloric sphincter regulates the speed at which food moves down to the small
intestine. After the stomach has done its work, the highly acidic mixture of gastric juices and
food (known as chyme) leaves the stomach, moves past the pyloric sphincter, and goes into the
duodenum before entering the small intestine.
Because the chemicals in the stomach work due to a subtle balance, many problems can arise
with the stomach. Some common conditions related to the stomach include: Indigestion,
heartburn, Nausea, Vomiting, Diarrhea, Ulcers, and Crohn’s disease.
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