Clinical Medical AssistingChapter 16: Digestive System

Objectives• Identify combining word forms of the digestive system and

their role in the formation of medical terms

• Define the structures and functions of the digestive system

• Identify common diseases of the digestive system and their treatment, as well as diagnostic procedures relating to the digestive system

• List abbreviations related to the digestive system

• Describe the relation of nutrition to the functioning of the digestive system

• Identify the basic nutrient types

• Explain the relationship and balance among the three energy providing nutrients

• Distinguish between water-soluble and fat-soluble vitamins

• Discuss herbal supplements

• Explain the reason for nutrition labels on food packaging

Objectives (con’t)

Chapter OverviewThe digestive system is also known as the gastrointestinal (GI) system. It includes several structures and accessory organs located along 30 feet of hollow tubing between the mouth and the anus that work to store and digest food, eliminate waste, and utilize nutrients. (See Figure 16.1.) Simply, the digestive system breaks down food into components that can be used as nutrients for all the cells of the body. To function effectively, the digestive system requires coordination with and input from other body systems, including the immune system, the muscular system, and the nervous system.

Structure and Function of the Digestive System

The chain of organs that makes up the digestive system is sometimes referred to as the alimentary canal, and the organs form a continuous tube from the mouth to the anus.

Mouth

The digestive tract begins at the mouth, the point at which food enters the body.

Esophagus

A tube that is approximately 10 inches long and covered in two layers of smooth muscle

StomachThe stomach is the sac-like structure that stores and digests large particles of food.

Small Intestine

The small intestine is a tube that is one inch in diameter and 20 feet in length.

Large Intestine

The large intestine is five feet long and two inches in diameter.

Liver

The liver is the largest gland in the body.

GallbladderThe gallbladder is a small sac underneath the liver that concentrates and stores bile.

Pancreas

The pancreas is a gland that has both endocrine and exocrine functions.

Nutrition

Proper nutrition is essential to the function of the digestive system.

NutrientsNutrients provide energy for the cells of the body and regulate body processes.

Carbohydrates

Carbohydrates are the body’s main source of energy.

FatsFats, or lipids, are also composed of carbon, hydrogen, and oxygen, but in different ratios and arrangements than carbohydrates.

Protein

A protein is composed of repeating units of amino acids.

VitaminsA vitamin is an organic molecule that regulates metabolic processes in the body.

Minerals

Minerals cannot be produced by the body and must be supplied by the diet.

WaterThe human body is composed of roughly 50% water.

Calories and Energy Balance

The amount of energy supplied by each nutrient is measured in calories.

Herbal and Dietary Supplements

Complementary and alternative medicine (CAM) encompasses diverse medical and healthcare systems, therapies, and products.

Diseases and Disorders of the Digestive System

When any of the steps in the digestive process (ingestion, absorption, digestion, or elimination) is hindered or altered, gastrointestinal complications can occur.

Appendicitis

Acute inflammation of the appendix

Signs and Symptoms of Appendicitis

Usually begins with generalized abdominal pain that eventually localizes to the lower right abdomen

CirrhosisA progressive and irreversible condition in which the cells of the liver are gradually destroyed due to chronic hepatic inflammation

Signs and Symptoms of Cirrhosis

Early signs of cirrhosis are general and diffuse.

Constipation

Constipation is the decreased frequency of bowel movements or difficulty defecating.

Signs and Symptoms of Constipation

Constipation is characterized by hard, dry, and infrequent bowel movements. The bowel movements may be painful.

DiarrheaDiarrhea is defined as an increased frequency and decreased consistency of fecal matter compared with an individual’s normal bowel habits.

Signs and Symptoms of Diarrhea

Diarrhea is characterized by frequent, liquid stools.

Gastroenteritis

An inflammation of the stomach and intestines

Signs and Symptoms of Gastroenteritis

Gastroenteritis is characterized by fever, nausea, abdominal pain, cramping, diarrhea, and vomiting.

Gastroesophageal Reflux Disease

Often referred to as heartburn, is a common problem

Hepatitis

An inflammation caused by a viral infection of the liver

Irritable Bowel Syndrome

A common GI syndrome characterized by chronic abdominal pain and altered bowel habits

Inflammatory Bowel Disease

Includes ulcerative colitis (UC) and Crohn’s disease

Obesity

Nearly 100 million American adults are overweight or obese.

Pancreatitis

An acute or chronic inflammation of the pancreas

Peptic Ulcer DiseaseBy the frequent recurrence of peptic ulcers, which are lesions in the mucosal lining of the stomach (gastric ulcer) or in the first part of the small intestine (duodenal ulcer).

Diagnostic Procedures and Therapeutic Modalities of the

Digestive System

The symptoms of many GI diseases and disorders overlap with each other and involve multiple body systems.

Colonoscopy

A colonoscopy is a procedure used to visualize the inside of the colon and rectum.

Gastroscopy

The visualization of the esophagus, stomach, and duodenum with a flexible, fiber-optic endoscope.

Radiological Studies

X-rays are used to visualize areas of the GI tract and can be used to diagnose a variety of conditions.

Occult Blood Test

A fecal occult blood test (FOBT) is used to identify the presence of blood in the feces that is not visible to the naked eye.

Colostomy

An artificial opening of the colon that allows fecal material to be excreted from the body through the abdominal wall

Ileostomy

An artificial opening in the ileum that allows chyme in the small intestine to empty through a tube in the abdominal wall

Therapeutic Diets

Designed to correct or compensate for disease states, including malnutrition, diabetes mellitus, cardiovascular disease, and even cancer

Summary• The gastrointestinal (GI) system includes the structures

and organs that store and digest food, eliminate waste, and utilize nutrients. It includes the mouth, esophagus, stomach, small intestine, large intestine, liver, gallbladder, and pancreas.

• The entire digestive process takes place in four steps: ingestion, digestion, absorption, and elimination.